Schizoid personality disorder
|Schizoid personality disorder|
|People with schizoid personality disorder often prefer solitary activities.|
|Symptoms||Pervasive emotional detachment, reduced affect, lack of close friends, apathy, anhedonia, unintentional insensitivity to social norms, asexuality, preoccupation with fantasy, autistic thinking without loss of skill to recognize reality|
|Usual onset||Late childhood or adolescence|
|Types||Languid schizoid, remote schizoid, depersonalized schizoid, affectless schizoid (Millon's subtypes)|
|Risk factors||Family history|
|Diagnostic method||Based on symptoms|
|Differential diagnosis||Other mental disorders with psychotic symptoms (schizophrenia, delusional disorder, and a bipolar or depressive disorder with psychotic features), personality change due to another medical condition, substance use disorders, autism spectrum disorder, other personality disorders and personality traits|
|Treatment||Not yet studied.|
|Medication||Not general practice but may include low dose benzodiazepines, β-blockers, nefazodone, bupropion, low dose of risperidone or olanzapine|
|Cluster A (odd)|
|Cluster B (dramatic)|
|Cluster C (anxious)|
Schizoid personality disorder (/
The cause of SPD is uncertain, but there is some evidence of links and shared genetic risk between SPD, other cluster A personality disorders (such as schizotypal personality disorder) and schizophrenia. Thus, SPD is considered to be a "schizophrenia-like personality disorder". It is diagnosed by clinical observation, and it can be very difficult to distinguish SPD from other disorders such as Asperger syndrome, with which it is sometimes comorbid. This is complicated by clinical overlap in symptoms and the existence of a long-noted subgroup of mostly male Asperger's patients who go on to develop SPD.
The effectiveness of psychotherapeutic and pharmacological treatments for the disorder have yet to be empirically and systematically investigated. While low doses of atypical antipsychotics were originally also used to treat some symptoms of SPD, their use is no longer recommended. The substituted amphetamine bupropion may be used to treat associated anhedonia. However, it is not general practice to treat SPD with medications, other than for the short-term treatment of acute co-occurring disorders (e.g. depression). Talk therapies such as cognitive behavioral therapy (CBT) may not be effective, because people with SPD may have hard time forming a good working relationship with a therapist. People with SPD rarely seek treatment for their condition.
SPD is a poorly studied disorder, and there is little clinical data on SPD because it is rarely encountered in clinical settings. Studies have generally reported a prevalence of less than 1% (a few estimates, however, have been as high as 4%). It affects slightly more males than females. SPD is linked to negative outcomes, including a significantly compromised quality of life, reduced overall functioning even after 15 years and one of the lowest levels of "life success" of all personality disorders (measured as "status, wealth and successful relationships"). Bullying is particularly common towards schizoid individuals. Suicide may be a running mental theme for schizoid individuals, though they are not likely to actually attempt one. Some symptoms of SPD (e.g. solitary lifestyle and emotional detachment), however, have been stated as general risk factors for serious suicidal behaviour.
- 1 Signs and symptoms
- 2 Causes
- 3 Diagnosis
- 4 Treatment
- 5 Development and course
- 6 Epidemiology
- 7 History
- 8 See also
- 9 Notes
- 10 References
- 11 External links
Signs and symptoms
People with SPD are often aloof, cold and indifferent, which causes interpersonal difficulty. Most individuals diagnosed with SPD have trouble establishing personal relationships or expressing their feelings meaningfully. They may remain passive in the face of unfavorable situations. Their communication with other people may be indifferent and terse at times. Schizoid personality types are challenged to achieve the ability to assess the impact of their own actions in social situations.
When someone violates the personal space of an individual with SPD, it suffocates them and they must free themselves to be independent. People who have SPD tend to be happiest when in relationships in which their partner places few emotional or intimate demands on them and doesn't expect phatic or social niceties. It is not necessarily people they want to avoid, but negative or positive emotional expectations, emotional intimacy and self-disclosure. Therefore, it is possible for individuals with SPD to form relationships with others based on intellectual, physical, familial, occupational or recreational activities, as long as there is no need for emotional intimacy. Donald Winnicott explains this is because schizoid individuals "prefer to make relationships on their own terms and not in terms of the impulses of other people." Failing to attain that, they prefer isolation. In general, friendship among schizoids is usually limited to one person, often also schizoid, forming what has been called a union of two eccentrics; "within it – the ecstatic cult of personality, outside it – everything is sharply rejected and despised".
Although there is the belief people with schizoid personality disorder are complacent and unaware of their feelings, many recognize their differences from others. Some individuals with SPD who are in treatment say "life passes them by" or they feel like living inside of a shell; they see themselves as "missing the bus" and speak of observing life from a distance.
Aaron Beck and his colleagues report that people with SPD seem comfortable with their aloof lifestyle and consider themselves observers, rather than participants, in the world around them. But they also mention that many of their schizoid patients recognize themselves as socially deviant (or even defective) when confronted with the different lives of ordinary people – especially when they read books or see movies focusing on relationships. Even when schizoid individuals may not long for closeness, they can become weary of being "on the outside, looking in". These feelings may lead to depression or depersonalisation. If they do, schizoid people often experience feeling "like a robot" or "going through life in a dream".
According to Guntrip, Klein and others, people with SPD may possess a hidden sense of superiority and lack dependence on other people's opinions. This is very different from the grandiosity seen in narcissistic personality disorder, which is described as "burdened with envy" and with a desire to destroy or put down others. Additionally, schizoids do not go out of their way to achieve social validation.:60 Unlike the narcissist, the schizoid will often keep their creations private to avoid unwelcome attention or the feeling that their ideas and thoughts are being appropriated by the public.:174
The related schizotypal personality disorder and schizophrenia are reported to have ties to creative thinking, and it is speculated that the internal fantasy aspect of schizoid personality disorder may also be reflective of this thinking. Alternatively, there has been an especially large contribution of people with schizoid symptoms to science and theoretical areas of knowledge: maths, physics, economics, etc. At the same time, people with SPD are helpless at many practical activities due to their symptoms.
The 'secret schizoid'
Many schizoid individuals display an engaging, interactive personality, contradicting the observable characteristic emphasized by the DSM-5 and ICD-10 definitions of the schizoid personality. Guntrip (using ideas of Klein, Fairbairn and Winnicott) classifies these individuals as "secret schizoids", who behave with socially available, interested, engaged and involved interaction yet remain emotionally withdrawn and sequestered within the safety of the internal world.:17 Klein distinguishes between a "classic" SPD and a "secret" SPD, which occur "just as often" as each other. Klein cautions one should not miss identifying the schizoid person as a result of the patient's defensive, compensatory interaction with the external world. He suggests one ask the person what his or her subjective experience is, to detect the presence of the schizoid refusal of emotional intimacy and preference for objective fact.
Frequently, a schizoid individual's social functioning improves, sometimes dramatically, when the individual knows he or she is an anonymous participant in a real-time conversation or correspondence, e.g. in an online chatroom or message board. Indeed, it is often the case the individual's online correspondent will report nothing amiss in the individual's engagement and affect. A 2013 study looking at personality disorders and Internet use found that being online more hours per day predicted signs of SPD. Additionally, SPD correlated with lower phone call use and fewer Facebook friends.
Descriptions of the schizoid personality as "hidden" behind an outward appearance of emotional engagement have been recognized since 1940, with Fairbairn's description of "schizoid exhibitionism", in which the schizoid individual is able to express a great deal of feeling and to make what appear to be impressive social contacts yet in reality gives nothing and loses nothing. Because they are "playing a part", their personality is not involved. According to Fairbairn, the person disowns the part he is playing, and the schizoid individual seeks to preserve his personality intact and immune from compromise. The schizoid's false persona is based around what those around them define as normal or good behaviour, as a form of compliance.:143 Further references to the secret schizoid come from Masud Khan, Jeffrey Seinfeld and Philip Manfield, who give a description of an SPD individual who "enjoys" public speaking engagements but experiences great difficulty in the breaks when audience members would attempt to engage him emotionally. These references expose the problems in relying on outer observable behavior for assessing the presence of personality disorders in certain individuals.
A pathological reliance on fantasizing and preoccupation with inner experience is often part of the schizoid withdrawal from the world. Fantasy thus becomes a core component of the self in exile, though fantasizing in schizoid individuals is far more complicated than a means of facilitating withdrawal.:64
Fantasy is also a relationship with the world and with others by proxy. It is a substitute relationship, but a relationship nonetheless, characterized by idealized, defensive and compensatory mechanisms. This is self-contained and free from the dangers and anxieties associated with emotional connection to real persons and situations. Klein explains it as "an expression of the self struggling to connect to objects, albeit internal objects. Fantasy permits schizoid patients to feel connected, and yet still free from the imprisonment in relationships. In short, in fantasy one can be attached (to internal objects) and still be free." This aspect of schizoid pathology has been generously elaborated in works by R. D. Laing, Donald Winnicott and Ralph Klein.:64
People with SPD are sometimes sexually apathetic, though they do not typically suffer from anorgasmia. Their preference to remain alone and detached may cause their need for sex to appear to be less than that of those who do not have SPD. Sex often causes individuals with SPD to feel that their personal space is being violated, and they commonly feel that masturbation or sexual abstinence is preferable to the emotional closeness they must tolerate when having sex. Significantly broadening this picture are notable exceptions of SPD individuals who engage in occasional or even frequent sexual activities with others.
Fairbairn notes that schizoids can fear that in a relationship, their needs will weaken and exhaust their partner, or their idiosyncratic views will drive the partner away, so they feel forced to disown them, adopt a persona and move to satisfy solely the needs of the partner. The net result of this is a loss of dignity and sense of self within any relationship they enter, eventually leading to intolerable frustration and friction. Appel notes that these fears result in the schizoid's negativism, stubbornness and reluctance to love. Thus, a central conflict of the schizoid is between an immense longing for relationships but a deep anxiety and avoidance of relationships, manifested by the choosing of the "lesser evil" of abandoning others.:100
Harry Guntrip:303 describes the "secret sexual affair" entered into by some married schizoid individuals as an attempt to reduce the quantity of emotional intimacy focused within a single relationship, a sentiment echoed by Karen Horney's "resigned personality", who may exclude sex as "too intimate for a permanent relationship, and instead satisfy his sexual needs with a stranger", separating sex from long-term relationships. "Conversely, he may more or less restrict a relationship to merely sexual contacts and not share other experiences with the partner." Jeffrey Seinfeld, professor of social work at New York University, has published a volume on SPD:104 that details examples of "schizoid hunger", which may manifest as sexual promiscuity. Seinfeld provides an example of a schizoid woman who would covertly attend various bars to meet men for the purpose of gaining impersonal sexual gratification, an act which alleviated her feelings of hunger and emptiness.
Salman Akhtar describes this dynamic interplay of overt versus covert sexuality and motivations of some SPD individuals with greater accuracy. Rather than following the narrow proposition that schizoid individuals are either sexual or asexual, Akhtar suggests that these forces may both be present in an individual despite their rather contradictory aims. A clinically accurate picture of schizoid sexuality must therefore include the overt signs: "asexual, sometimes celibate; free of romantic interests; averse to sexual gossip and innuendo", as well as possible covert manifestations of "secret voyeuristic and pornographic interests; vulnerable to erotomania; and tendency towards perversions", although none of these necessarily apply to all people with SPD.
Individuals with SPD have long been noted to have an increased rate of unconventional sexual tendencies and paraphilias, such as fetishism, preoccupations with body parts, voyeurism, homosexuality, hebephilia or bestiality, though these are rarely acted upon. Instead, they often form part of their fantasies. They tend to be stronger with increased severity of the disorder and may be seen as part of the fundamental emotional and moral rift between themselves and others that leads them to avoid relationships. The schizoid is however often labelled asexual or presents with "a lack of a sexual identity". Kernberg states that this apparent lack of a sexuality does not represent a lack of sexual definition but rather a combination of several strong fixations to cope with the same conflicts.:125 People with SPD are often able to pursue their fantasies with fetish pornography readily available on the Internet while remaining completely unengaged with the outside world. People with SPD may often gravitate towards sexually immature or unavailable partners to ease any fears about expected sexual contact. Since there is no desire for genital sex, the relationship is based around other themes.:127
American psychologist Salman Akhtar provided a comprehensive phenomenological profile of SPD in which classic and contemporary descriptive views are synthesized with psychoanalytic observations. This profile is summarized in the table reproduced below that lists clinical features that involve six areas of psychosocial functioning and are organized by "overt" and "covert" manifestations.
"Overt" and "covert" are intended to denote seemingly contradictory aspects that may both simultaneously be present in an individual. It should be noted that these designations do not necessarily imply their conscious or unconscious existence. The covert characteristics are by definition difficult to discern and not immediately apparent. Additionally, the lack of data on the frequency of many of the features makes their relative diagnostic weight difficult to distinguish at this time. However, Akhtar states that his profile has several advantages over the DSM in terms of maintaining historical continuity of the use of the word schizoid, valuing depth and complexity over descriptive oversimplification and helping provide a more meaningful differential diagnosis of SPD from other personality disorders.
|Overt characteristics||Covert characteristics|
|Love and sexuality|
|Ethics, standards, and ideals|
Some evidence suggests the cluster A personality disorders have shared genetic and environmental risk factors, and there is an increased prevalence of schizoid personality disorder in relatives of people with schizophrenia and schizotypal personality disorder. Twin studies with schizoid personality disorder traits (e.g. low sociability and low warmth) suggest these are inherited. Besides this indirect evidence, the direct heritability estimates of SPD range from 50 to 59%. To Sula Wolff, who did extensive research and clinical work with children and teenagers with schizoid symptoms, "schizoid personality has a constitutional, probably genetic, basis." The link between SPD and being underweight may also point to the involvement of biological factors.
In general, prenatal caloric malnutrition, premature birth and a low birth weight are risk factors for being afflicted by mental disorders and may contribute to the development of schizoid personality disorder as well. Those who have experienced traumatic brain injury may be also at risk of developing features reflective of schizoid personality disorder.
The Diagnostic and Statistical Manual of Mental Disorders is a widely used manual for diagnosing mental disorders. DSM- 5 still includes schizoid personality disorder with the same criteria as in DSM-IV. In the DSM-5, SPD is described as a pervasive pattern of detachment from social relationships and a restricted range of expression of emotions in interpersonal settings, beginning by early adulthood and present in a variety of contexts, as indicated by at least four of the following:
- Neither desires nor enjoys close relationships, including being part of a family.
- Almost always chooses solitary activities.
- Has little, if any, interest in having sexual experiences with another person.
- Takes pleasure in few, if any, activities.
- Lacks close friends or confidants other than first-degree relatives.
- Appears indifferent to the praise or criticism of others.
- Shows emotional coldness, detachment, or flattened affectivity.
According to the DSM, those with SPD may often be unable to, or will rarely express aggressiveness or hostility, even when provoked directly. These individuals can seem vague or drifting about their goals and their lives may appear directionless. Others view them as indecisive in their actions, self-absorbed, absent-minded and detached from their surroundings (''not with it'' or ''in a fog''). Excessive daydreaming is often present. In cases with severe defects in the capacity to form social relationships, dating and marriage may not be possible.
The Classification of Mental and Behavioural Disorders of ICD-10 lists schizoid personality disorder under (F60.1).
The general criteria of personality disorder (F60) should be met first. In addition, at least four of the following criteria must be present:
- Few, if any, activities provide pleasure.
- Displays emotional coldness, detachment, or flattened affectivity.
- Limited capacity to express warm, tender feelings for others as well as anger.
- Appears indifferent to either praise or criticism from others.
- Little interest in having sexual experiences with another person (taking into account age).
- Almost always chooses solitary activities.
- Excessive preoccupation with fantasy and introspection.
- Neither desires, nor has, any close friends or confiding relationships (or only one).
- Marked insensitivity to prevailing social norms and conventions; if these are not followed, this is unintentional.
- A sense of superiority
- Loss of affect
The description of Guntrip's nine characteristics should clarify some differences between the traditional DSM portrait of SPD and the traditional informed object relations view. All nine characteristics are consistent. Most, if not all, must be present to diagnose a schizoid disorder.
More details about each of the characteristics can be found in the Harry Guntrip article.
Theodore Millon restricted the term "schizoid" to those personalities who lack the capacity to form social relationships. He characterizes their way of thinking as being vague and void of thoughts and as sometimes having a "defective perceptual scanning". Because they often do not perceive cues that trigger affective responses, they experience fewer emotional reactions.
For Millon, SPD is distinguished from other personality disorders in that it is "the personality disorder that lacks a personality." He criticizes that this may be due to the current diagnostic criteria: They describe SPD only by an absence of certain traits, which results in a "deficit syndrome" or "vacuum". Instead of delineating the presence of something, they mention solely what is lacking. Therefore, it is hard to describe and research such a concept.
|Languid schizoid (including depressive features)||Marked inertia; deficient activation level; intrinsically phlegmatic, lethargic, weary, leaden, lackadaisical, exhausted, enfeebled. Unable to act with spontaneity or seeks simplest pleasures, may experience profound angst, yet lack the vitality to express it strongly.|
|Remote schizoid (including avoidant and schizotypal features)||Distant and removed; inaccessible, solitary, isolated, homeless, disconnected, secluded, aimlessly drifting; peripherally occupied. Seen among people who would have been otherwise capable of developing normal emotional life but having been subjected to intense hostility lost their innate capability to form bonds. Some residual anxiety is present. Often seen among the homeless; many are dependent on public support.|
|Depersonalized schizoid (including schizotypal features)||Disengaged from others and self; self is disembodied or distant object; body and mind sundered, cleaved, dissociated, disjoined, eliminated. Often seen as simply staring into the empty space or being occupied with something substantial while actually being occupied with nothing at all.|
|Affectless schizoid (including compulsive features)||Passionless, unresponsive, unaffectionate, chilly, uncaring, unstirred, spiritless, lackluster, unexcitable, unperturbed, cold; all emotions diminished. Combines the preference for rigid schedule (obsessive-compulsive feature) with the coldness of the schizoid.|
While SPD shares several symptoms with other mental disorders, here are some important differentiating features:
|Depression||People who have SPD may also suffer from clinical depression. However, this is not always the case. Unlike depressed people, persons with SPD generally do not consider themselves inferior to others. They may recognize instead that they are "different".|
|Avoidant personality disorder (AvPD)||While people affected with APD avoid social interactions due to anxiety or feelings of incompetence, those with SPD do so because they are genuinely indifferent to social relationships. A 1989 study, however, found that "schizoid and avoidant personalities were found to display equivalent levels of anxiety, depression, and psychotic tendencies as compared to psychiatric control patients." There also seems to be some shared genetic risk between SPD and AvPD (see schizoid-avoidant behavior). Several sources to date have confirmed the synonymy of SPD and avoidant attachment style. However, the distinction should be made that individuals with SPD characteristically do not seek social interactions merely due to lack of interest, while those with avoidant attachment style can in fact be interested in interacting with others but without establishing connections of much depth or length due to having little tolerance for any kind of intimacy.|
|Other personality disorders||Schizoid and narcissistic personality disorders can seem similar in some respects (e.g. both show identity confusion, may lack warmth and spontaneity, avoid deep relationships with intimacy). Another commonality observed by Akhtar is preferring ideas over people and displaying intellectual hypertrophy, with a corresponding lack of rootedness in bodily existence. There are, nonetheless, important differences. The schizoid hides his need for dependency and is rather fatalistic, passive, cynical, overtly bland or vaguely mysterious. The narcissist is, in contrast, ambitious and competitive and exploits others for his dependency needs. There are also parallels between SPD and obsessive-compulsive personality disorder (OCPD), such as detachment, restricted emotional expression and rigidity. However, in OCPD the capacity to develop intimate relationships is usually intact, but deep contacts may be avoided because of an unease with emotions and a devotion to work.|
|Asperger syndrome||There may be substantial difficulty in distinguishing Asperger syndrome (AS), sometimes called "schizoid disorder of childhood", from SPD. But while AS is an autism spectrum disorder, SPD is classified as a "schizophrenia-like" personality disorder. There is some overlap, as some people with autism also qualify for a diagnosis of schizotypal or schizoid PD. However, one of the distinguishing features of schizoid PD is a restricted affect and an impaired capacity for emotional experience and expression. Persons with AS are "hypo-mentalizers", i.e., they fail to recognize social cues such as verbal hints, body language and gesticulation, but those with schizophrenia-like personality disorders tend to be "hyper-mentalizers", overinterpreting such cues in a generally suspicious way (see Imprinted brain theory). Although they may have been socially isolated from childhood onward, most people with schizoid personality disorder displayed well-adapted social behavior as children, along with apparently normal emotional function. SPD also does not require impairments in nonverbal communication such as a lack of eye contact, unusual prosody or a pattern of restricted interests or repetitive behaviors.|
|Simple-type schizophrenia||Simple-type schizophrenia is a diagnosis in the ICD-10 but is not present in the current DSM-5 or the upcoming ICD-11. It is a form of schizophrenia characterised by negative symptoms and a lack of psychotic features. Both simple schizophrenia and SPD share many negative symptoms like avolition, impoverished thinking and flat affect. Although they may look almost identical, what distinguishes them is usually the severity. Also, SPD is characterized by a lifelong pattern without change, whereas simple schizophrenia represents a deterioration.|
SPD is often found to be comorbid with at least one of several disorders or pathologies. Sometimes, a person with SPD may meet criteria for an additional personality disorder; when this happens, it is most often avoidant, schizotypal or paranoid PD. Alexithymia (the inability to identify and describe emotions) is often present in SPD. Sharon Ekleberry suggests that some people with schizoid personality features may occasionally experience instances of brief reactive psychosis when under stress.
Substance use disorder
Very little data exists for rates of substance use disorder among people with SPD, but existing studies suggest they are less likely to have substance abuse problems than the general population. One study found that significantly fewer boys with SPD had alcohol problems than a control group of non-schizoids. Another study evaluating personality disorder profiles in substance abusers found that substance abusers who showed schizoid symptoms were more likely to abuse one substance rather than many, in contrast to other personality disorders such as borderline, antisocial or histrionic, which were more likely to abuse many.
American psychotherapist Sharon Ekleberry states that the impoverished social connections experienced by people with SPD limit their exposure to the drug culture and that they have limited inclination to learn how to do illegal drugs. Describing them as "highly resistant to influence", she additionally states that even if they could access illegal drugs, they would be disinclined to use them in public or social settings, and because they would be more likely to use alcohol or cannabis alone than for social disinhibition, they would not be particularly vulnerable to negative consequences in early use.
Suicide may be a running theme for schizoid individuals, in part due to the knowledge of the large-scale ostracism that would result if their idiosyncratic views were revealed and their experience that most, if not all people, are unrelatable or have polar opposite reactions to them on societally sensitive issues, though they are not likely to actually attempt one. They might be down and depressed when all possible connections have been cut off, but as long as there is some relationship or even hope for one the risk will be low. The idea of suicide is a driving force against the person's schizoid defenses. As Klein says: "For some schizoid patients, its presence is like a faint, barely discernible background noise, and rarely reaches a level that breaks into consciousness. For others, it is an ominous presence, an emotional sword of Damocles. In any case, it is an underlying dread that they all experience." Often among people with SPD, there is a rationally grounded and reasoned position on why they want to die, and this "suicidal construct" takes a stable position in the mind. Demonstrative suicides or suicide blackmail, as seen in cluster B personality disorders such as borderline, histrionic or antisocial, are extremely rare among schizoid individuals. Schizoids tend to hide their suicidal thoughts and intentions.
Several studies have reported an overlap or comorbidity with the autism spectrum disorder Asperger syndrome. Asperger syndrome had traditionally been called "schizoid disorder of childhood", and Eugen Bleuler coined both the terms "autism" and "schizoid" to describe withdrawal to an internal fantasy, against which any influence from outside becomes an intolerable disturbance. In a 2012 study of a sample of 54 young adults with Asperger syndrome, it was found that 26% of them also met criteria for SPD, the highest comorbidity out of any personality disorder in the sample (the other comorbidities were 19% for obsessive–compulsive personality disorder, 13% for avoidant personality disorder and one female with schizotypal personality disorder). Additionally, twice as many men with Asperger syndrome met criteria for SPD than women. While 41% of the whole sample were unemployed with no occupation, this rose to 62% for the Asperger's and SPD comorbid group. Tantam suggested that Asperger syndrome may confer an increased risk of developing SPD. A 2019 study found that 54% of a group of males aged 11 to 25 with Asperger syndrome showed significant SPD traits, with 6% meeting full diagnostic criteria for SPD, compared to 0% of a control.
In the 2012 study, it was noted that the DSM may complicate diagnosis by requiring the exclusion of a pervasive developmental disorder (PDD) before establishing a diagnosis of SPD. The study found that social interaction impairments, stereotyped behaviours and specific interests were more severe in the individuals with Asperger syndrome also fulfilling SPD criteria, against the notion that social interaction skills are unimpaired in SPD. The authors believe that substantial subgroup of people with autism spectrum disorder or PDD have clear "schizoid traits" and correspond largely to the "loners" in Lorna Wing's classification The autism spectrum (Lancet 1997), described by Sula Wolff. The authors of the 2019 study hypothesised that it is extremely likely that historic cohorts of adults diagnosed with SPD either also had childhood-onset autistic syndromes or were misdiagnosed. They stressed that further research to clarify overlap and distinctions between these two syndromes was strongly warranted, especially given that high-functioning autism spectrum disorders are now recognised in around 1% of the population.
A study which looked at the body mass index (BMI) of a sample of both male adolescents diagnosed with SPD and those diagnosed with Asperger syndrome found that the BMI of all patients was significantly below normal. Clinical records indicated abnormal eating behaviour by some patients. Some patients would only eat when alone and refused to eat out. Restrictive diets and fears of disease were also found. It was suggested that the anhedonia of SPD may also cover eating, leading schizoid individuals to not enjoy it. Alternatively, it was suggested that schizoid individuals may not feel hunger as strongly as others or not respond to it, a certain withdrawal "from themselves".
Another study looked at rates of anti-social conduct in boys with either schizoid personality disorder or Asperger syndrome compared with a control group of non-schizoid individuals and found the incidence of anti-social conduct to be the same in both groups. However, the schizoid boys stole significantly less. Upon follow-up in adulthood, out of a matched group of 19 boys with SPD and 19 boys without, four of the schizoid boys reported having internal violent fantasies (concerned with Zulu wars, abattoirs, fascists and communists and a collection of knives, respectively), which were pursued entirely by themselves, while the only non-schizoid subject to report a violent fantasy life shared his with a group of young men (dressing up and riding motorcycles as a self-styled "panzer" group).
An absent parent or socio-economic disadvantage did not seem to affect the risk of anti-social conduct in schizoid individuals as much as it did in non-schizoid individuals. Absent parents and parental socio-economic disadvantage were also less common in the schizoid group.
The original concept of the schizoid character developed by Ernst Kretschmer in the 1920s comprised an amalgamation of avoidant, schizotypal and schizoid traits. It was not until 1980 and the work of Theodore Millon that led to splitting this concept into three personality disorders (now schizoid, schizotypal and avoidant). This caused debate about whether this was accurate or if these traits were different expressions of a single personality disorder.
A 2012 article suggested that two different disorders may better represent SPD: one affect-constricted disorder (belonging to schizotypal PD) and a seclusive disorder (belonging to avoidant PD). They called for the replacement of the SPD category from future editions of the DSM by a dimensional model which would allow for the description of schizoid traits on an individual basis.
Some critics such as Nancy McWilliams of Rutgers University and Parpottas Panagiotis of European University Cyprus argue that the definition of SPD is flawed due to cultural bias and that it does not constitute a mental disorder but simply an avoidant attachment style requiring more distant emotional proximity.[note 1] If that is true, then many of the more problematic reactions these individuals show in social situations may be partly accounted for by the judgements commonly imposed on people with this style. However, impairment is mandatory for any behaviour to be diagnosed as a personality disorder. SPD seems to satisfy this criterion because it is linked to negative outcomes. These include a significantly compromised quality of life, reduced overall functioning even after 15 years and one of the lowest levels of "life success" of all personality disorders (measured as "status, wealth and successful relationships").
People with schizoid personality disorder rarely seek treatment for their condition. This is an issue found in many personality disorders, which prevents many people who are afflicted with these conditions from coming forward for treatment: they tend to view their condition as not conflicting with their self-image and their abnormal perceptions and behaviors as rational and appropriate. There is little data on the effectiveness of various treatments on this personality disorder because it is seldom seen in clinical settings. However, those in treatment have the option of medication and therapy.
No medications are indicated for directly treating schizoid personality disorder, but certain medications may reduce the symptoms of SPD as well as treat co-occurring mental disorders. The symptoms of SPD mirror the negative symptoms of schizophrenia, such as anhedonia, blunted affect and low energy, and SPD is thought to be part of the "schizophrenic spectrum" of disorders, which also includes the schizotypal and paranoid personality disorders, and may benefit from the medications indicated for schizophrenia. Originally, low doses of atypical antipsychotics like risperidone or olanzapine were used to alleviate social deficits and blunted affect. However, a 2012 review concluded that atypical antipsychotics were ineffective for treating personality disorders.
In contrast, the substituted amphetamine bupropion may be used to treat anhedonia. Likewise, modafinil may be effective in treating some of the negative symptoms of schizophrenia, which are reflected in the symptomatology of SPD and therefore may help as well. Lamotrigine, SSRIs, TCAs, MAOIs and hydroxyzine may help counter social anxiety in people with SPD if present, though social anxiety may not be a main concern for the people who have SPD. However, it is not general practice to treat SPD with medications, other than for the short-term treatment of acute co-occurring axis I conditions (e.g. depression).
Despite the relative emotional comfort, psychoanalytic therapy of schizoid individuals takes a long time and causes many difficulties. Schizoids are generally poorly involved in psychotherapy due to difficulties in establishing empathic relations with a psychotherapist and low motivation for treatment.
Supportive psychotherapy is used in an inpatient or outpatient setting by a trained professional that focuses on areas such as coping skills, improvement of social skills and social interactions, communication and self-esteem issues. People with SPD may also have a perceptual tendency to miss subtle differences in expression. That causes an inability to pick up hints from the environment because social cues from others that might normally provoke an emotional response are not perceived. That in turn limits their own emotional experience. The perception of varied events only increases their fear for intimacy and limits them in their interpersonal relationships. Their aloofness may limit their opportunities to refine the social skills and behavior necessary to effectively pursue relationships.[clarification needed]
Besides psychodynamic therapy, cognitive behavioral therapy (CBT) can be used. But because CBT generally begins with identifying the automatic thoughts, one should be aware of the potential hazards that can happen when working with schizoid patients. People with SPD seem to be distinguished from those with other personality disorders in that they often report having few or no automatic thoughts at all. That poverty of thought may have to do with their apathetic lifestyle. But another possible explanation could be the paucity of emotion many schizoids display, which would influence their thought patterns as well.
Socialization groups may help people with SPD. Educational strategies in which people who have SPD identify their positive and negative emotions also may be effective. Such identification helps them to learn about their own emotions and the emotions they draw out from others and to feel the common emotions with other people with whom they relate. This can help people with SPD create empathy with the outside world.
The concept of "closer compromise" means that the schizoid patient may be encouraged to experience intermediate positions between the extremes of emotional closeness and permanent exile. A lack of injections of interpersonal reality causes an impoverishment in which the schizoid individual's self-image becomes increasingly empty and volatilized and leads the individual to feel unreal. To create a more adaptive and self-enriching interaction with others in which one "feels real", the patient is encouraged to take risks through greater connection, communication and sharing of ideas, feelings and actions. Closer compromise means that while the patient's vulnerability to anxieties is not overcome, it is modified and managed more adaptively. Here, the therapist repeatedly conveys to the patient that anxiety is inevitable but manageable, without any illusion that the vulnerability to such anxiety can be permanently dispensed with. The limiting factor is the point at which the dangers of intimacy become overwhelming and the patient must again retreat.
Klein suggests that patients must take the responsibility to place themselves at risk and to take the initiative for following through with treatment suggestions in their personal lives. It is emphasized that these are the therapist's impressions and that he or she is not reading the patient's mind or imposing an agenda but is simply stating a position that is an extension of the patient's therapeutic wish. Finally, the therapist directs attention to the need to employ these actions outside of the therapeutic setting.
Klein suggests that "working through" is the second longer-term tier of psychotherapeutic work with schizoid patients. Its goals are to change fundamentally the old ways of feeling and thinking and to rid oneself of the vulnerability to those emotions associated with old feelings and thoughts. A new therapeutic operation of "remembering with feeling" that draws on D. W. Winnicott's concepts of false self and true self is called for. The patient must remember with feeling the emergence of his or her false self through childhood and remember the conditions and proscriptions that were imposed on the individual's freedom to experience the self in company with others.
Remembering with feeling ultimately leads the patient to understand that he or she had no opportunity to choose from a selection of possible ways of experiencing the self and of relating with others and had few, if any, options other than to develop a schizoid stance toward others. The false self was simply the best way in which the patient could experience the repetitive predictable acknowledgement, affirmation and approval necessary for emotional survival while warding off the effects associated with the abandonment depression.
If the goal of shorter-term therapy is for patients to understand that they are not the way they appear to be and can act differently, then the longer-term goal of working through is for patients to understand who and what they are as human beings, what they truly are like and what they truly contain. The goal of working through is not achieved by the patient's sudden discovery of a hidden, fully formed talented and creative self living inside, but is a process of slowly freeing oneself from the confinement of abandonment depression in order to uncover a potential. It is a process of experimentation with the spontaneous, nonreactive elements that can be experienced in relationship with others.[clarification needed]
Working through abandonment depression is a complicated, lengthy and conflicted process that can be an enormously painful experience in terms of what is remembered and what must be felt. It involves mourning and grieving for the loss of the illusion that the patient had adequate support for the emergence of the real self. There is also a mourning for the loss of an identity, the false self, which the person constructed and with which he or she has negotiated much of his or her life. The dismantling of the false self requires relinquishing the only way that the patient has ever known of how to interact with others. This interaction was better than not to have a stable, organized experience of the self, no matter how false, defensive or destructive that identity may be.
The dismantling of the false self "leaves the impaired real self with the opportunity to convert its potential and its possibilities into actualities." Working through brings unique rewards, of which the most important element is the growing realization that the individual has a fundamental, internal need for relatedness that may be expressed in a variety of ways. "Only schizoid patients", suggests Klein, "who have worked through the abandonment depression ... ultimately will believe that the capacity for relatedness and the wish for relatedness are woven into the structure of their beings, that they are truly part of who the patients are and what they contain as human beings. It is this sense that finally allows the schizoid patient to feel the most intimate sense of being connected with humanity more generally, and with another person more personally. For the schizoid patient, this degree of certainty is the most gratifying revelation, and a profound new organizer of the self experience.":127
Development and course
SPD can be first apparent in childhood and adolescence with solitariness, poor peer relationships and underachievement in school. This may mark these children as different and make them subject to teasing.
Being a personality disorder, which are usually chronic and long-lasting mental conditions, schizoid personality disorder is not expected to improve with time without treatment; however, much remains unknown because it is rarely encountered in clinical settings.
SPD is uncommon in clinical settings (about 2.2%) and occurs slightly more commonly in males. It is rare compared with other personality disorders, with a prevalence estimated at less than 1% of the general population.
Philip Manfield suggests that the "schizoid condition", which roughly includes the DSM schizoid, avoidant and schizotypal personality disorders, is represented by "as many as forty percent of all personality disorders." Manfield adds "This huge discrepancy [from the ten percent reported by therapists for the condition] is probably largely because someone with a schizoid disorder is less likely to seek treatment than someone with other axis-II disorders."
A 2008 study assessing personality and mood disorder prevalence among homeless people at New York City drop-in centres reported an SPD rate of 65% among this sample. The study did not assess homeless people who did not show up at drop-in centres, and the rates of most other personality and mood disorders within the drop-in centres was lower than that of SPD. The authors noted the limitations of the study, including the higher male-to-female ratio in the sample and the absence of subjects outside the support system or receiving other support (e.g., shelters) as well as the absence of subjects in geographical settings outside New York City, a large city often considered a magnet for disenfranchised people.
A University of Colorado Colorado Springs study comparing personality disorders and Myers–Briggs Type Indicator types found that the disorder had a significant correlation with the Introverted (I) and Thinking (T) preferences.
The term "schizoid" was coined in 1908 by Eugen Bleuler to designate a human tendency to direct attention toward one's inner life and away from the external world, a concept akin to introversion in that it was not viewed in terms of psychopathology. Bleuler labeled the exaggeration of this tendency the "schizoid personality". He described these personalities as "comfortably dull and at the same time sensitive, people who in a narrow manner pursue vague purposes".
In 1910, August Hoch introduced a very similar concept called the "shut-in" personality. Characteristics of it were reticence, seclusiveness, shyness and a preference for living in fantasy worlds, among others. In 1925, Russian psychiatrist Grunja Sukhareva described a "schizoid psychopathy" in a group of children, resembling today's SPD and Asperger's. About a decade later Pyotr Gannushkin also included Schizoids and Dreamers in his detailed typology of personality types.
Studies on the schizoid personality have developed along two distinct paths. The "descriptive psychiatry" tradition focuses on overtly observable, behavioral and describable symptoms and finds its clearest exposition in the DSM-5. The dynamic psychiatry tradition includes the exploration of covert or unconscious motivations and character structure as elaborated by classic psychoanalysis and object-relations theory.
- Unsociability, quietness, reservedness, seriousness and eccentricity.
- Timidity, shyness with feelings, sensitivity, nervousness, excitability, fondness of nature and books.
- Pliability, kindliness, honesty, indifference, silence and cold emotional attitudes.
These characteristics were the precursors of the DSM-III division of the schizoid character into three distinct personality disorders: schizotypal, avoidant and schizoid. Kretschmer himself, however, did not conceive of separating these behaviors to the point of radical isolation but considered them to be simultaneously present as varying potentials in schizoid individuals. For Kretschmer, the majority of schizoids are not either oversensitive or cold, but they are oversensitive and cold "at the same time" in quite different relative proportions, with a tendency to move along these dimensions from one behavior to the other.
The second path, that of dynamic psychiatry, began in 1924 with observations by Eugen Bleuler, who observed that the schizoid person and schizoid pathology were not things to be set apart.:p. 5 Ronald Fairbairn's seminal work on the schizoid personality, from which most of what is known today about schizoid phenomena is derived, was presented in 1940. Here, Fairbairn delineated four central schizoid themes:
- The need to regulate interpersonal distance as a central focus of concern.
- The ability to mobilize self-preservative defenses and self-reliance.
- A pervasive tension between the anxiety-laden need for attachment and the defensive need for distance that manifests in observable behavior as indifference.
- An overvaluation of the inner world at the expense of the outer world.:p. 9
Following Fairbairn, the dynamic psychiatry tradition has continued to produce rich explorations on the schizoid character, most notably from writers Nannarello (1953), Laing (1965), Winnicott (1965), Guntrip (1969), Khan (1974), Akhtar (1987), Seinfeld (1991), Manfield (1992) and Klein (1995).
- Counterphobic attitude
- Dissociation (psychology)
- Sluggish cognitive tempo
- See Neurodiversity
- "F60 Specific personality disorders" (PDF). The ICD-10 Classification of Mental and Behavioural Disorders – Diagnostic criteria for research. Geneva: World Health Organization. p. 149.
- American Psychiatric Association (1968). Diagnostic and Statistical Manual of Mental Disorders, 2nd Edition. Washington, D. C. p. 42. doi:10.1176/appi.books.9780890420355.dsm-ii (inactive 2019-08-20). ISBN 978-0-89042-035-5.
- Millon, Theodore; Millon, Carrie M.; Meagher, Sarah E. (2012). "The Schizoid Personality (Chapter 11)". Personality Disorders in Modern Life. Seth D. Grossman, Rowena Ramnath (2nd ed.). John Wiley & Sons. pp. 371–374. ISBN 0-471-23734-5.
- Michelle L. Esterberg (2010). "Cluster A Personality Disorders: Schizotypal, Schizoid and Paranoid Personality Disorders in Childhood and Adolescence". Journal of Psychopathology and Behavioral Assessment. 32 (4): 515–528. doi:10.1007/s10862-010-9183-8. PMC 2992453. PMID 21116455.
- "Schizoid Personality Disorder (pp. 652–655)". Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (2013). 2013. ISBN 978-0-89042-555-8.
- MedlinePlus (2014). "Schizoid Personality Disorder". National Library of Medicine.
- Sonny Joseph (1997). "Chapter 3, Schizoid Personality Disorder". Personality Disorders: New Symptom-Focused Drug Therapy. Psychology Press. pp. 45–56. ISBN 9780789001344.
- Paul Emmelkamp (2013): Personality Disorders. p.54. See Cramer (2006) and Hong (2005) for details.
- Skodol (2011). "Personality Disorder Types Proposed for DSM-5". Journal of Personality Disorders. 25 (2): 136–69. doi:10.1521/pedi.2011.25.2.136. PMID 21466247.
It [SPD] was found by Ulrich (2007) to have the lowest functioning among the PDs with respect to achievement and interpersonal relations...
- Joseph Triebwasser; et al. (2012). "Schizoid Personality Disorder". Journal of Personality Disorders. 26 (6): 919–926. doi:10.1521/pedi.2012.26.6.919. PMID 23281676.
... it seems reasonable for DSM-5 to move away from ScPD as a categorical diagnosis and instead to include Detachment traits as a codable dimension that can have a substantial impact on an individual’s functioning and quality of life, and that can moreover be a focus of treatment.
- Coid, Jeremy; Yang, Min; Tyrer, Peter; Roberts, Amanda; Ullrich, Simone (May 2006). "Prevalence and correlates of personality disorder in Great Britain". The British Journal of Psychiatry: The Journal of Mental Science. 188 (5): 423–31. doi:10.1192/bjp.188.5.423. ISSN 0007-1250. PMID 16648528.
- Arthur S. Reber (2009) . The Penguin Dictionary of Psychology (4th ed.). London; New York: Penguin Books. p. 706. ISBN 9780141030241. OCLC 288985213.
- Salman Akhtar (1987). Schizoid Personality Disorder: A Synthesis of Developmental, Dynamic, and Descriptive Features. American Journal of Psychotherapy. 41. pp. 499–518. doi:10.1176/appi.psychotherapy.19184.108.40.2069. ISBN 9781461627685. PMID 3324773. Archived from the original on 2017-07-31. Retrieved 2017-02-10.
- Dennis S. Charney, Eric J. Nestler (2005): Neurobiology of Mental Illness. Oxford Press. ISBN 978-0-19-518980-3. Schizophrenia-like Personality Disorders. p. 240.
- Tantam, D. (December 1988). "Lifelong eccentricity and social isolation. II: Asperger's syndrome or schizoid personality disorder?". The British Journal of Psychiatry: The Journal of Mental Science. 153: 783–791. doi:10.1192/bjp.153.6.783. ISSN 0007-1250. PMID 3256377.
- Sharon C. Ekleberry (2008). "Cluster A - Schizoid Personality Disorder and Substance Use Disorders". Integrated Treatment for Co-Occurring Disorders: Personality Disorders and Addiction. Routledge. pp. 31–32. ISBN 978-0789036933.
- Lugnegård, Tove; Hallerbäck, Maria Unenge; Gillberg, Christopher (May 2012). "Personality disorders and autism spectrum disorders: what are the connections?". Comprehensive Psychiatry. 53 (4): 333–340. doi:10.1016/j.comppsych.2011.05.014. ISSN 1532-8384. PMID 21821235.
- Cook, Michal (2019-05-03). "Pronounced Overlap of Autistic and Schizoid Personality Trait Burden in Adolescence". IMFAR. Cite journal requires
- Maher, Alicia R.; Theodore, George (2012). "Summary of the Comparative Effectiveness Review on Off-Label Use of Atypical Antipsychotics". Journal of Managed Care Pharmacy. 18 (5 Supp B): 1–20. doi:10.18553/jmcp.2012.18.s5-b.1. ISSN 1083-4087.
- "Schizoid personality disorder". Mayo Foundation for Medical Education and Research (2016).
- Descriptions from DSM-III (1980) and DSM-5 (2013):"Schizoid PD, Associated features (p. 310)" and "Schizoid PD (p. 652–655)".
- James F. Masterson; Ralph Klein (1995). Disorders of the Self – The Masterson Approach. New York: Brunner / Mazel. pp. 25–27, pp. 54–55, pp. 95–143 (therapy). ISBN 9780876307861.
- Levi-Belz, Y.; Gvion, Y.; Levi, U.; Apter, A. (2019). "Beyond the mental pain: A case-control study on the contribution of schizoid personality disorder symptoms to medically serious suicide attempts". Comprehensive Psychiatry. 90: 102–109. doi:10.1016/j.comppsych.2019.02.005. PMID 30852349.
- Ronald D. Laing (1965). "The Inner Self in the Schizoid Condition". The Divided Self: an Existential Study in Sanity and Madness. Harmondsworth, Middlesex; Baltimore: Penguin Books. pp. 82–100. ISBN 9780140207347. OCLC 5212085.
- Philip Manfield (1992). Split self/split object: understanding and treating borderline, narcissistic, and schizoid disorders. Jason Aronson. pp. 204–207. ISBN 978-0-87668-460-3.
- Donald Winnicott (2006). The Family and Individual Development. Routledge. p. 73. ISBN 978-0415402774.
- Ernst Kretschmer (March 2013). "Chapter 10. Schizoid temperaments". Body structure and character. Studies on the constitution and theory of temperaments (in Russian). Ripol Classic. ISBN 9785458358392.
- Jeffrey J. Magnavita (1997). Restructuring Personality Disorders: A Short-Term Dynamic Approach. New York: The Guilford Press. p. 237. ISBN 978-1-57230-185-6.
- Aaron T. Beck, Arthur Freeman (1990). "Chapter 7 Schizoid and Schizotypal PD (p.120-146)". Cognitive Therapy of Personality Disorders (1st ed.). The Guilford Press. pp. 125 (Millon), 127–129 (cognitive therapy conceptualization). ISBN 9780898624342. OCLC 906420553.
- "Treatment of schizoid personality: An analytic psychotherapy handbook - ProQuest". search.proquest.com. Retrieved 2019-08-22.
- David Schuldberg (2001). "Six subclinical spectrum traits in normal creativity". Creativity Research Journal. 13 (1): 5–16. doi:10.1207/s15326934crj1301_2.
- George Domino (2002). "Creativity and Ego Defense Mechanisms: Some Exploratory Empirical Evidence". Creativity Research Journal. 14 (1): 17–25. doi:10.1207/S15326934CRJ1401_2.
- Kinney, Dennis K.; Richards, Ruth (2001). "Creativity in Offspring of Schizophrenic and Control Parents: An Adoption Study". Creativity Research Journal. 13 (1): 17–25. doi:10.1207/S15326934CRJ1301_3.
- Белорусов, Сергей (2017-09-05). Очерки душевной патологии. И возможности ее коррекции соотносительно с духовным измерением бытия (in Russian). Litres. ISBN 9785040548330.
- Avner Falk (2008). Islamic Terror: Conscious and Unconscious Motives. ABC-CLIO. p. 98. ISBN 978-0-313-35764-0.
- Rosen, L. D.; Whaling, K.; Rab, S.; Carrier, L. M.; Cheever, N. A. (2013). "Is Facebook creating "iDisorders"? The link between clinical symptoms of psychiatric disorders and technology use, attitudes and anxiety". Computers in Human Behavior. 29 (3): 1243–1254. doi:10.1016/j.chb.2012.11.012. ISSN 0747-5632.
- W. R. D. Fairbairn (2013). Psychoanalytic Studies of the Personality. Routledge. p. 3–17. ISBN 978-1-134-84213-1.
- Masud Khan (1974). "The Role of phobic and counter-phobic mechanisms and separation anxiety in schizoid character formation". The Privacy of the Self – Papers on Psychoanalytic Theory and Technique. New York: International Universities Press. p. 70. ISBN 978-0823643103.
- Jeffrey Seinfeld (1991). The Empty Core: An Object Relations Approach to Psychotherapy of the Schizoid Personality. J. Aronson. ISBN 978-0-87668-611-9.
Seinfeld writes: "The schizoid may also seem to be sociable and involved in relationships. However, he is frequently playing a role and not 'fully' involved, unconsciously disowning this role..."
- Donald Woods Winnicott (1991). Playing and Reality. Psychology Press. p. 26–38. ISBN 978-0-415-03689-4.
- Nannarello, Joseph J. (1953). "Schizoid". The Journal of Nervous and Mental Disease. 118 (3): 237–249. doi:10.1097/00005053-195309000-00004. PMID 13118367.
- "Treatment of schizoid personality: An analytic psychotherapy handbook - ProQuest". search.proquest.com. Retrieved 2019-08-22.
- Harry Guntrip (1969). Schizoid Phenomena, Object-Relations, and The Self. New York: International Universities Press. ISBN 978-1-85575-032-6.
- Karen Horney (1999). "Resignation: The Appeal of Freedom". Neurosis and Human Growth: The Struggle Towards Self-Realization. Routledge. pp. 264–265. ISBN 9780415210959.
- Kenneth S. Kendler (2006). "Dimensional representations of DSM-IV Cluster A personality disorders in a population-based sample of Norwegian twins: a multivariate study". Psychological Medicine. 36 (11): 1583–1591. doi:10.1017/S0033291706008609. PMID 16893481.
- Paul H. Blaney PhD (2014). Oxford Textbook of Psychopathology. Oxford University Press. p. 649. ISBN 978-0-19-981184-7.
- Sula Wolff (1995). Loners – The Life Path of Unusual Children. Routledge. p. 35. ISBN 978-0-415-06665-5.
- Amber A. Mather (2008). "Associations Between Body Weight and Personality Disorders in a Nationally Representative Sample". Psychosomatic Medicine. 70 (9): 1012–1019. doi:10.1097/psy.0b013e318189a930. PMID 18842749.
- Kathryn M. Abel (2010). "Birth weight, schizophrenia, and adult mental disorder: is risk confined to the smallest babies?". Archives of General Psychiatry. 67 (9): 923–930. doi:10.1001/archgenpsychiatry.2010.100. PMID 20819986.
- Willem H.J. Martens (2010). "Schizoid personality disorder linked to unbearable and inescapable loneliness". The European Journal of Psychiatry. 24 (1). doi:10.4321/S0213-61632010000100005.
- Brigham Young University (2014): Head injuries can make children loners. For original study, see Levan, Ashley; Baxter, Leslie; Kirwan, C. Brock; Black, Garrett; Gale, Shawn D (2015). "Right Frontal Pole Cortical Thickness and Social Competence in Children With Chronic Traumatic Brain Injury". Journal of Head Trauma Rehabilitation. 30 (2): E24–E31. doi:10.1097/HTR.0000000000000040. PMID 24714213.
- R.L. Jenkins; S. Glickman (April 1946). "The Schizoid Child". American Journal of Orthopsychiatry. 16 (2): 255–61. doi:10.1111/j.1939-0025.1946.tb05379.x.
- DiGiuseppe, Raymond; Tafrate, Raymond Chip (2007). Understanding Anger Disorders. Oxford University Press, USA. p. 207. ISBN 9780195170795.
- "Theodore Millon – The Retiring or Schizoid Personality". millonpersonality.com.
- James Overholser (1989) (November 1989). "Differentiation between schizoid and avoidant personalities: an empirical test". Canadian Journal of Psychiatry. 34 (8): 785–90. doi:10.1177/070674378903400808. PMID 2819642.
- Malcolm L. West and A. E. Sheldon-Keller (1994). Patterns of Relating An Adult Attachment Perspective. New York: Guilford Press. pp. 111–113. ISBN 978-0-89862-671-1.
- Fritz-Georg Lehnhardt, Astrid Gawronski, Kathleen Pfeiffer, Hanna Kockler, Leonhard Schilbach, and Kai Vogeley (2013). "The investigation and differential diagnosis of Asperger syndrome in adults". Deutsches Ärzteblatt International. 110 (45): 755–63. doi:10.3238/arztebl.2013.0755. PMC 3849991. PMID 24290364.CS1 maint: multiple names: authors list (link)
- World Health Organization (1993) – The ICD-10 Classification of Mental and Behavioural Disorders. "Simple schizophrenia" is classified F20.6.
- "ICD-11 - Mortality and Morbidity Statistics". icd.who.int. Retrieved 2019-08-22.
- American Psychiatric Association, DSM-IV (1994). Appendix B: Criteria Sets and Axes Provided for Further Study. p. 713. ISBN 9780890420621.
- Coolidge, Frederick L. (2012). "Are alexithymia and schizoid personality disorder synonymous diagnoses?". Comprehensive Psychiatry. 54 (2): 141–148. doi:10.1016/j.comppsych.2012.07.005. PMID 23021894.
- Wolff, S.; Cull, A. (August 1986). "'Schizoid' personality and antisocial conduct: a retrospective case not study". Psychological Medicine. 16 (3): 677–687. doi:10.1017/S0033291700010424. ISSN 0033-2917. PMID 3763781.
- Skinstad, Anne Helene; Swain, Annette (2001-01-01). "Comorbidity in a Clinical Sample of Substance Abusers". The American Journal of Drug and Alcohol Abuse. 27 (1): 45–64. doi:10.1081/ADA-100103118. ISSN 0095-2990. PMID 11373036.
- Анатольевна, Панченко Евгения; Сергеевич, Положий Борис (2011). "РАССТРОЙСТВА ЛИЧНОСТИ У ПАЦИЕНТОВ, СОВЕРШИВШИХ СУИЦИДАЛЬНЫЕ ПОПЫТКИ". Российский психиатрический журнал (3). ISSN 1560-957X.
- Kuhn R (2004). "Eugen Bleuler's concepts of psychopathology". Hist Psychiatry. 15 (3): 361–366. doi:10.1177/0957154X04044603. PMID 15386868. The quote is a translation of Bleuler's 1910 original.
- Livesley, W. J.; West, M. (February 1986). "The DSM-III Distinction between schizoid and avoidant personality disorders". Canadian Journal of Psychiatry. 31 (1): 59–62. doi:10.1177/070674378603100112. PMID 3948107.
- Nancy McWilliams (2011). Psychoanalytic Diagnosis: Understanding Personality Structure in the Clinical Process (2nd ed.). New York: Guilford Press. p. 196. ISBN 9781609184940.
- Parpottas Panagiotis (2012). "A critique on the use of standard psychopathological classifications in understanding human distress: The example of 'Schizoid Personality Disorder'". Counselling Psychology Review. 27 (1): 44–52.
- McVey, D. & Murphy, N. (eds.) (2010) Treating Personality Disorder: Creating Robust Services for People with Complex Mental Health Needs, ISBN 0-203-84115-8.
- Scoriels, Linda (2013). "Modafinil effects on cognition and emotion in schizophrenia and its neurochemical modulation in the brain". Neuropharmacology. 64: 168–184. doi:10.1016/j.neuropharm.2012.07.011. PMID 22820555.
- McWilliams, Nancy. (1994). Psychoanalytic diagnosis : understanding personality structure in the clinical process. New York: Guilford Press. p. 480. ISBN 0898621992. OCLC 30035262.
- Ed. N. G. Neznanova, Yu. A. Alexandrovsky, L. M. Bardenshtein, V. D. Vida, V. N. Krasnov, Yu. V. Popov. - M (2009). "Chapter 7. F6. Personality Disorders and Behavior in Adults". Psychiatry .-- S. . - 512 s. - (Clinical Recommendations Series). Moscow: GEOTAR-Media. pp. 304–307. ISBN 978-5-9704-1297-8.CS1 maint: multiple names: authors list (link)
- George Eman Vaillant (1985). "Maturity of Ego Defenses in Relation to DSM-III Axis II Personality Disorder". Archives of General Psychiatry. 42 (6): 597–601. doi:10.1001/archpsyc.1985.01790290079009. PMID 4004502. Manfield backs his claim up with this study; it showed that of the seventy-four people inner city males found to have personality disorders, thirty were schizoid or avoidant.
- Connolly, Adrian J. (2008). "Personality disorders in homeless drop-in center clients" (PDF). Journal of Personality Disorders. 22 (6): 573–588. doi:10.1521/pedi.2008.22.6.573. PMID 19072678. Archived from the original (PDF) on 2009-06-17.
- "An Empirical Investigation of Jung's Personality Types and Psychological Disorder Features" (PDF). Journal of Psychological Type/University of Colorado Colorado Springs. 2001. Archived (PDF) from the original on 2014-01-25. Retrieved August 10, 2013. Italic or bold markup not allowed in:
- Both types shared a detachment from the world but Schizoids also showed eccentricity and paradoxicality of emotional life and behavior, emotional coldness and dryness, unpredictability combined with lack of intuition and ambivalence (e.g., simultaneous presence of both stubbornness and submissiveness). Characteristic of Dreamers were tenderness and fragility, receptiveness to beauty, weak-willedness and listlessness, luxuriant imagination, dereism and usually an inflated self-concept. (From: Gannushkin, P.B (1933). Manifestations of psychopathies: statics, dynamics, systematic aspects.)
- Ernst Kretschmer (1931). Physique and Character. London: Routledge (International Library of Psychology,1999). ISBN 978-0-415-21060-7. OCLC 858861653.
- Eugen Bleuler – Textbook of Psychiatry, New York: Macmillan (1924)
- Donald Winnicott (1965): The Maturational Processes and the Facilitating Environment: Studies in the Theory of Emotional Development. Karnac Books. ISBN 9780946439843.