|Other names||Childhood type schizophrenia; schizophrenia, childhood type; childhood-onset schizophrenia (COS); very early-onset schizophrenia (VEOS); schizophrenic syndrome of childhood|
|Specialty||Child psychiatry (EU), Child and adolescent psychiatry (USA), clinical psychology|
|Symptoms||Hallucinations, delusions, disorganized behavior or catatonia, negative symptoms (i.e., avolition or reduced affect display)|
|Usual onset||Before the age of 13 years|
|Types||Episodic-progredient/shiftlike childhood schizophrenia (malignant, paranoid and slow-progressive sub-types), continuous childhood schizophrenia, recurrent childhood schizophrenia (the rarest form – 5 % of all cases)|
|Differential diagnosis||Major depressive disorder or bipolar disorder with psychotic or catatonic features, brief psychotic disorder, delusional disorder, obsessive–compulsive disorder and body dysmorphic disorder, autism spectrum disorder or communication disorders, other mental disorders associated with a psychotic episode|
|Frequency||1⁄5 of all forms of psychosis of the schizophrenia spectrum; 1.66:1000 among children (0–14 years)|
Childhood schizophrenia (also known as childhood-onset schizophrenia, and very early-onset schizophrenia) is essentially the same in characteristics as schizophrenia that develops at a later age, but has an onset before the age of 13, and is more difficult to diagnose. Schizophrenia is characterized by positive symptoms that can include hallucinations, delusions, and disorganized speech; negative symptoms, such as blunted affect and avolition and apathy, and a number of cognitive impairments. Differential diagnosis is problematic since several other neurodevelopmental disorders, including autism-spectrum disorder, language disorder, and attention deficit hyperactivity disorder, also have signs and symptoms similar to childhood-onset schizophrenia.
The disorder presents symptoms such as auditory and visual hallucinations, strange thoughts or feelings, and abnormal behavior, profoundly impacting the child's ability to function and sustain normal interpersonal relationships. Delusions are often not systematized and vague. Among the psychotic symptoms seen in childhood schizophrenia non-verbal auditory hallucinations are the most common, and include noises such as shots, knocks, bangs. Other symptoms can include irritability, searching for imaginary objects, or low performance. It typically presents after the age of seven. About 50% of young children diagnosed with schizophrenia experience severe neuropsychiatric symptoms. Studies have demonstrated that diagnostic criteria are similar to those of adult schizophrenia. Neither DSM-5 nor ICD-11 list "childhood schizophrenia" as a separate diagnosis. Diagnosis is based on behavior observed by caretakers and, in some cases depending on age, self reports.
Classification of mental disorders
Diagnostic and Statistical Manual of Mental Disorders
Childhood schizophrenia was not directly added to the DSM until 1968, when it was added to the DSM-II, which set forth diagnostic criteria similar to that of adult schizophrenia. "Schizophrenia, childhood type" was a DSM-II diagnosis with diagnostic code 295.8. It's equivalent to "schizophrenic reaction, childhood type" (code 000-x28) in DSM-I (1952). "Schizophrenia, childhood type" was successfully removed from the DSM-III (1980), and in the Appendix C they wrote: "there is currently no way of predicting which children will develop Schizophrenia as adults". Instead of childhood schizophrenia they proposed to use of "infantile autism" (299.0x) and "childhood onset pervasive developmental disorder" (299.9x).
In the DSM-III-R (1987), DSM-IV (1994), DSM-IV-TR (2000), DSM-5 (2013) there are no "childhood schizophrenia". The rationale for this approach was that since the clinical picture of adult schizophrenia and childhood schizophrenia is identical, childhood schizophrenia should not be a separate disorder. However, the section in schizophrenia's Development and Course in DSM-5, includes references to childhood-onset schizophrenia.
International Classification of Diseases
In the International Classification of Diseases 8th revision (ICD-8, 1967) there was a category (295.8) "Other" in the schizophrenia section (295). "Other" includes: atypical forms of schizophrenia, infantile autism, schizophrenia, childhood type, NOS (Not Otherwise Specified), schizophrenia of specified type not classifiable under 295.0–295.7, schizophreniform attack or psychosis.
Unspecified psychoses with origin specific to childhood (code 299.9) in the International Classification of Diseases 9th revision (ICD-9) includes "child psychosis NOS", "schizophrenia, childhood type NOS" and "schizophrenic syndrome of childhood NOS".
Signs and symptoms
Schizophrenia is a mental disorder that is expressed in abnormal mental functions and disturbed behavior.
The signs and symptoms of childhood schizophrenia are nearly the same as adult-onset schizophrenia. Some of the earliest signs that a young child may develop schizophrenia are lags in language and motor development. Some children engage in activities such as flapping the arms or rocking, and may appear anxious, confused, or disruptive on a regular basis. Children may experience hallucinations, but these are often difficult to differentiate from just normal imagination or child play. Visual hallucinations are more commonly found in children than in adults. It is often difficult for children to describe their hallucinations or delusions, making very early-onset schizophrenia especially difficult to diagnose in the earliest stages. The cognitive abilities of children with schizophrenia may also often be lacking, with 20% of patients showing borderline or full intellectual disability.
Very early-onset schizophrenia refers to onset before the age of thirteen. The prodromal phase, which precedes psychotic symptoms, is characterized by deterioration in school performance, social withdrawal, disorganized or unusual behavior, a decreased ability to perform daily activities, a deterioration in self-care skills, bizarre hygiene and eating behaviors, changes in affect, a lack of impulse control, hostility and aggression, and lethargy.
Auditory hallucinations are the most common of the positive symptoms in children. Auditory hallucinations may include voices that are conversing with each other or voices that are speaking directly to the children themselves. Many children with auditory hallucinations believe that if they do not listen to the voices, the voices will harm them or someone else. Tactile and visual hallucinations seem relatively rare. Children often attribute the hallucinatory voices to a variety of beings, including family members or other people, evil forces ("the Devil", "a witch", "a spirit"), animals, characters from horror movies (Bloody Mary, Freddy Krueger) and less clearly recognizable sources ("bad things," "the whispers"). Command auditory hallucinations (also known as imperative hallucinations) were common and experienced by more than 1⁄2 of the group in a research at the Bellevue Hospital Center's Children's Psychiatric Inpatient Unit. And voices repeat and repeat: "Kill somebody!", "Kill her, kill her!". Delusions are reported in more than half of children with schizophrenia, but they are usually less complex than those of adults. Delusions are often connected with hallucinatory experiences. In a research delusions were characterized as persecutory for the most part, but some children reported delusions of control. Many said they were being tortured by the beings causing their visual and auditory hallucinations, some thought disobeying their voices would cause them harm.
Some degree of thought disorder was observed in a test group of children in Bellevue Hospital. They displayed illogicality, tangentialiry (a serious disturbance in the associative thought process), and loosening of associations.
There is no known single cause or causes of schizophrenia, however, it is a heritable disorder.
Several environmental factors, including perinatal complications and prenatal maternal infections could cause schizophrenia. These factors in a greater severity or frequency could result in an earlier onset of schizophrenia. Maybe a genetic predisposition is an important factor too, familial illness reported for childhood-onset schizophrenic patients.
There is "considerable overlap" in the genetics of childhood-onset and adult-onset schizophrenia, but in childhood-onset schizophrenia there is a higher number of "rare allelic variants". An important gene for adolescent-onset schizophrenia is the catechol-O-methyltransferase gene, a gene that regulates dopamine. Children with schizophrenia have an increase in genetic deletions or duplication mutations and some have a specific mutation called 22q11 deletion syndrome, which accounts for up to 2% of cases.
Neuroimaging studies have found differences between the medicated brains of individuals with schizophrenia and neurotypical brains, though research does not know the cause of the difference. In childhood-onset schizophrenia, there appears to be a faster loss of cerebral grey matter during adolescence. Studies have reported that adverse childhood experiences (ACEs) are the most preventable cause of the development of psychiatric disorders such as schizophrenia. ACEs have the potential to impact on the structure and function of the brain; structural changes revealed have been related to stress. Findings also report that different areas of the brain are affected by different types of maltreatment.
In 2013, the American Psychiatric Association released the fifth edition of the DSM (DSM-5). According to the manual, to be diagnosed with schizophrenia, two diagnostic criteria have to be met over much of the time of a period of at least one month, with a significant impact on social or occupational functioning for at least six months. The DSM diagnostic criteria outlines that the person has to be experiencing either delusions, hallucinations, or disorganized speech. In other words, an individual does not have to be experiencing delusions or hallucinations to receive a diagnosis of schizophrenia. A second symptom could be negative symptoms, or severely disorganized or catatonic behavior. Only two symptoms are required for a diagnosis of schizophrenia, resulting in different presentations for the same disorder.
In practice, agreement between the two systems is high. The DSM-5 criteria puts more emphasis on social or occupational dysfunction than the ICD-10. The ICD-10, on the other hand, puts more emphasis on first-rank symptoms. The current proposal for the ICD-11 criteria for schizophrenia recommends adding self-disorder as a symptom.
First rank symptoms
First-rank symptoms are psychotic symptoms that are particularly characteristic of schizophrenia, which were put forward by Kurt Schneider in 1959. Their reliability for the diagnosis of schizophrenia has been questioned since then. A 2015 systematic review investigated the diagnostic accuracy of first rank symptoms:
|These studies were of limited quality. Results show correct identification of people with schizophrenia in about 75-95% of the cases although it is recommended to consult an additional specialist. The sensitivity of FRS was about 60%, so it can help diagnosis and, when applied with care, mistakes can be avoided. In lower resource settings, when more sophisticated methods are not available, first rank symptoms can be very valuable.|
The definition of schizophrenia remained essentially the same as that specified by the 2000 version of DSM (DSM-IV-TR), but DSM-5 makes a number of changes:
- Subtype classifications were removed.
- Catatonia is no longer so strongly associated with schizophrenia.
- In describing a person's schizophrenia, it is recommended that a better distinction be made between the current state of the condition and its historical progress, to achieve a clearer overall characterization.
- Special treatment of Schneider's first-rank symptoms is no longer recommended.
- Schizoaffective disorder is better defined to demarcate it more cleanly from schizophrenia.
- An assessment covering eight domains of psychopathology – including reality distortion, negative symptoms, thought and action disorganization, cognition impairment, catatonia, and symptoms similar to those found in certain mood disorders, such as whether hallucination or mania is experienced – is recommended to help clinical decision-making.
A professional who believes a child has schizophrenia usually conducts a series of tests to rule out other causes of behavior, and pinpoint a diagnosis. Three different types of exams are performed: physical, laboratory, and psychological. Physical exams usually cover the basic assessments, including but not limited to; height, weight, blood pressure, and checking all vital signs to make sure the child is healthy. Laboratory tests include electroencephalogram EEG screening and brain imaging scans. Blood tests are used to rule out alcohol or drug effects, and thyroid hormone levels are tested to rule out hyper- or hypothyroidism.[medical citation needed] A psychologist or psychiatrist talks to a child about their thoughts, feelings, and behavior patterns. They also inquire about the severity of the symptoms, and the effects they have on the child's daily life. They may also discuss thoughts of suicide or self-harm in these one-on-one sessions. Some symptoms that may be looked at are early language delays, early motor development delays and school problems.
Age of first episode of psychosis
Childhood schizophrenia manifests before the age of 13 and is also known as very early-onset. Onset before the age of 18 is known as early-onset schizophrenia, and is rare; very early-onset is even rarer.
The onset of childhood schizophrenia usually follows a period of normal, or near normal, development. Strange interests, unusual beliefs, and social impairment can be prodromal symptoms of childhood schizophrenia, but can also be signs of autism spectrum disorder. Hallucinations and delusions are typical for schizophrenia, but not features of autism spectrum disorder. In children hallucinations must be separated from typical childhood fantasies. Since childhood disintegrative disorder (CDD) has a very similar set of symptoms and high comorbidity it can be misdiagnosed as childhood schizophrenia which can lead to prescribing ineffective medications. 
Research efforts are focusing on prevention in identifying early signs from relatives with associated disorders similar with schizophrenia and those with prenatal and birth complications. Prevention has been an ongoing challenge because early signs of the disorder are similar to those of other disorders. Also, some of the schizophrenic related symptoms are often found in children without schizophrenia or any other diagnosable disorder.
Current methods in treating early-onset schizophrenia follow a similar approach to the treatment of adult schizophrenia. Although modes of treatment in this population is largely understudied, the use of antipsychotic medication is commonly the first line of treatment in addressing symptoms. Recent literature has failed to determine if typical or atypical antipsychotics are most effective in reducing symptoms and improving outcomes. When weighing treatment options, it is necessary to consider the adverse effects of various medications used to treat schizophrenia and the potential implications of these effects on development. A 2013 systematic review compared the efficacy of atypical antipsychotics versus typical antipsychotics for adolescents:
|There is not any convincing evidence suggesting that atypical antipsychotic medications are superior to the older typical medications for the treatment of adolescents with psychosis. However, atypical antipsychotic medications may be more acceptable because fewer symptomatic adverse effects are seen in the short term. Little evidence is available to support the superiority of one atypical antipsychotic medication over another.|
Madaan et al. wrote that studies report efficacy of typical neuroleptics such as thioridazine, thiothixene, loxapine and haloperidol, high incidence of side effects such as extrapyramidal symptoms, akathisia, dystonias, sedation, elevated prolactin, tardive dyskinesia.
A very-early diagnosis of schizophrenia leads to a worse prognosis than other psychotic disorders. The primary area that children with schizophrenia must adapt to is their social surroundings. It has been found, however, that very early-onset schizophrenia carried a more severe prognosis than later-onset schizophrenia. Regardless of treatment, children diagnosed with schizophrenia at an early age suffer diminished social skills, such as educational and vocational abilities.[medical citation needed]
The grey matter in the cerebral cortex of the brain shrinks over time in people with schizophrenia; the question of whether antipsychotic medication exacerbates or causes this has been controversial. A 2015 meta-analysis found that there is a positive correlation between the cumulative amount of first generation antipsychotics taken by people with schizophrenia and the amount of grey matter loss, and a negative correlation with the cumulative amount of second-generation antipsychotics taken.
Schizophrenia disorders in children are rare. Boys are twice as likely to be diagnosed with childhood schizophrenia. There is often an disproportionately large number of males with childhood schizophrenia, because the age of onset of the disorder is earlier in males than females by about 5 years. People have been and still are reluctant to diagnose schizophrenia early on, primarily due to the stigma attached to it.
While very early-onset schizophrenia is a rare event, with prevalence of about 1:10,000, early-onset schizophrenia manifests more often, with an estimated prevalence of 0.5%.
Until the late nineteenth century, children were often diagnosed as suffering from psychosis like schizophrenia, but instead were said to suffer from "pubescent" or "developmental" insanity. Through the 1950s, childhood psychosis began to become more and more common, and psychiatrists began to take a deeper look into the issue.[failed verification]
Sante De Sanctis first wrote about child psychoses, in 1905. He called the condition "dementia praecocissima" (Latin, "very premature madness"), by analogy to the term then used for schizophrenia, "dementia praecox" (Latin, "premature madness). Sante de Sanctis characterized the condition by the presence of catatonia. Philip Bromberg thinks that "dementia praecocissima" is in some cases indistinguishable from childhood schizophrenia, and Leo Kanner believed that "dementia praecocissima" encompassed a number of pathological conditions.
Theodor Heller discovered a new syndrome dementia infantilis (Latin, "infantile madness") in 1909 which was named Heller syndrome. In ICD-11 Heller syndrome is classed as an autism spectrum subtype.
Also in 1909, Julius Raecke reported on ten cases of catatonia in children at the Psychiatric and Neurological Hospital of Kiel University, where he worked. He described symptoms similar to those previously recorded by Dr. Karl Ludwig Kahlbaum, including "stereotypies and bizarre urges, impulsive motor eruptions and blind apathy." He also reported refusal to eat, stupor with mutism, uncleanliness, indications of waxy flexibility and unmotivated eccentricity, and childish behavior.
A 1913 paper by Karl Pönitz, "Contribution to the Recognition of Early Catatonia", recounts a case study of a boy who manifested "typical catatonia" from the age of twelve, characterizing him as showing a "clear picture of schizophrenia."
Before 1980 the literature on "childhood schizophrenia" often described a "heterogeneous mixture" of different disorders, such as autism, symbiotic psychosis or psychotic disorder other than schizophrenia, pervasive developmental disorders and dementia infantilis.
- Diagnostic and statistical manual of mental disorders : DSM-5 (5th ed.). American Psychiatric Association. 2013. pp. 99–104. ISBN 9780890425541.
- Tiganov AS, Snezhnevsky AV, Orlovskaya DD (1999). "Шизофрения в детском и подростковом возрасте" [Schizophrenia in childhood and adolescence]. In Tiganov AS (ed.). Руководство по психиатрии в 2 томах [Textbook of Psychiatry in 2 volumes] (in Russian). Vol. 1. Moscow: "Медицина" = ["Medicine"]. pp. 472–488. ISBN 5-225-02676-1. // Research of childhood schizophrenia types by The Mental Health Research Center (MHRC) (Russia)
- Diagnostic and statistical manual of mental disorders : DSM-5 (5th ed.). American Psychiatric Association. 2013. pp. 102–103. ISBN 9780890425541.
- Kendhari J, Shankar R, Young-Walker L (July 2016). "A Review of Childhood-Onset Schizophrenia". Focus. 14 (3): 328–332. doi:10.1176/appi.focus.20160007. PMC 6526799. PMID 31975813.
- Ritsner MS, ed. (2011). Handbook of Schizophrenia Spectrum Disorders. II. Dordrecht, Heidelberg, London, New York: Springer Science+Business Media. pp. 195–205. doi:10.1007/978-94-007-0831-0. ISBN 978-94-007-0830-3.
- Bettes BA, Walker E (July 1987). "Positive and negative symptoms in psychotic and other psychiatrically disturbed children". Journal of Child Psychology and Psychiatry, and Allied Disciplines. Wiley-Blackwell. 28 (4): 555–68. doi:10.1111/j.1469-7610.1987.tb00223.x. PMID 3654807.
- Baribeau DA, Anagnostou E (December 2013). "A comparison of neuroimaging findings in childhood onset schizophrenia and autism spectrum disorder: a review of the literature". Frontiers in Psychiatry. 4: 175. doi:10.3389/fpsyt.2013.00175. PMC 3869044. PMID 24391605.
- Lambert LT (April–June 2001). "Identification and management of schizophrenia in childhood". Journal of Child and Adolescent Psychiatric Nursing. 14 (2): 73–80. doi:10.1111/j.1744-6171.2001.tb00295.x. PMID 11883626.
- Nicolson R, Rapoport JL (November 1999). "Childhood-onset schizophrenia: rare but worth studying". Biological Psychiatry. Elsevier BV. 46 (10): 1418–28. doi:10.1016/s0006-3223(99)00231-0. PMID 10578456. S2CID 45154449.
- Spencer EK, Campbell M (1994). "Children with schizophrenia: diagnosis, phenomenology, and pharmacotherapy". Schizophrenia Bulletin. 20 (4): 713–25. doi:10.1093/schbul/20.4.713. PMID 7701278.
- American Psychiatric Association (1968). Diagnostic and Statistical Manual of Mental Disorders, 2nd Edition. Washington, D. C. p. 35. doi:10.1176/appi.books.9780890420355.dsm-ii (inactive 2020-12-05). ISBN 978-0-89042-035-5.CS1 maint: DOI inactive as of December 2020 (link)
- Remschmidt HE, Schulz E, Martin M, Warnke A, Trott GE (1994). "Childhood-onset schizophrenia: history of the concept and recent studies" (PDF). Schizophrenia Bulletin. 20 (4): 727–45. doi:10.1093/schbul/20.4.727. PMID 7701279.
- American Psychiatric Association (1980). "Appendix C: Annotated Comparative Listing of DSM-II and DSM-lll". Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III). Washington, DC: American Psychiatric Publishing. p. 375.
- Spitzer RL, Cantwell DP (1980). "The DSM-III classification of the psychiatric disorders of infancy, childhood, and adolescence". Journal of the American Academy of Child Psychiatry. Elsevier BV. 19 (3): 356–70. doi:10.1016/s0002-7138(09)61059-1. PMID 6157706.
- Manual of the international statistical classification of diseases injuries and causes of death (PDF). Geneva: World Health Organization. 1977. p. 190.
- "ICD-10. Schizophrenia, schizotypal and delusional disorders (F20—F29)" (in Russian). Retrieved 3 December 2017.
- Jardri, Renaud (2014). "From Phenomenology to Neurophysiological Understanding of Hallucinations in Children and Adolescents". Schizophrenia Bulletin. 40: S221–S232. doi:10.1093/schbul/sbu029. PMC 4141307. PMID 24936083.
- Masi G, Mucci M, Pari C (2006). "Children with schizophrenia: clinical picture and pharmacological treatment". CNS Drugs. 20 (10): 841–66. doi:10.2165/00023210-200620100-00005. PMID 16999454. S2CID 41966134.
- Spencer EK, Campbell M (1994). "Children with schizophrenia: diagnosis, phenomenology, and pharmacotherapy" (PDF). Schizophrenia Bulletin. 20 (4): 713–25. doi:10.1093/schbul/20.4.713. PMID 7701278.
- Kallmann FJ, Roth B (February 1956). "Genetic aspects of preadolescent schizophrenia". The American Journal of Psychiatry. American Psychiatric Publishing. 112 (8): 599–606. doi:10.1176/ajp.112.8.599. PMID 13292546.
- Asarnow RF, Forsyth JK (October 2013). "Genetics of childhood-onset schizophrenia". Child and Adolescent Psychiatric Clinics of North America. 22 (4): 675–87. doi:10.1016/j.chc.2013.06.004. PMC 4364758. PMID 24012080.
- Godar SC, Bortolato M (2014). "Gene-sex interactions in schizophrenia: focus on dopamine neurotransmission". Frontiers in Behavioral Neuroscience. 8: 71. doi:10.3389/fnbeh.2014.00071. PMC 3944784. PMID 24639636.
- Squarcione C, Torti MC, Di Fabio F, Biondi M (2013). "22q11 deletion syndrome: a review of the neuropsychiatric features and their neurobiological basis". Neuropsychiatric Disease and Treatment. 9: 1873–84. doi:10.2147/NDT.S52188. PMC 3862513. PMID 24353423.
- Giusti-Rodríguez P, Sullivan PF (November 2013). "The genomics of schizophrenia: update and implications". The Journal of Clinical Investigation. 123 (11): 4557–63. doi:10.1172/JCI66031. PMC 3809776. PMID 24177465.
- Brent BK, Thermenos HW, Keshavan MS, Seidman LJ (October 2013). "Gray matter alterations in schizophrenia high-risk youth and early-onset schizophrenia: a review of structural MRI findings". Child and Adolescent Psychiatric Clinics of North America. 22 (4): 689–714. doi:10.1016/j.chc.2013.06.003. PMC 3767930. PMID 24012081.
- Shaw P, Gogtay N, Rapoport J (June 2010). "Childhood psychiatric disorders as anomalies in neurodevelopmental trajectories". Human Brain Mapping. Wiley-Blackwell. 31 (6): 917–25. doi:10.1002/hbm.21028. PMC 6870870. PMID 20496382. S2CID 18033463.
- Teicher MH, Samson JA (March 2016). "Annual Research Review: Enduring neurobiological effects of childhood abuse and neglect". Journal of Child Psychology and Psychiatry, and Allied Disciplines. 57 (3): 241–66. doi:10.1111/jcpp.12507. PMC 4760853. PMID 26831814.
- American Psychiatric Association (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington: American Psychiatric Publishing. ISBN 978-0-89042-555-8.
- Jakobsen KD, Frederiksen JN, Hansen T, Jansson LB, Parnas J, Werge T (2005). "Reliability of clinical ICD-10 schizophrenia diagnoses". Nordic Journal of Psychiatry. 59 (3): 209–12. doi:10.1080/08039480510027698. PMID 16195122. S2CID 24590483.
- Tandon R, Gaebel W, Barch DM, Bustillo J, Gur RE, Heckers S, et al. (October 2013). "Definition and description of schizophrenia in the DSM-5". Schizophrenia Research. 150 (1): 3–10. doi:10.1016/j.schres.2013.05.028. PMID 23800613. S2CID 17314600.
- American Psychiatric Association (2013). Diagnostic and Statistical Manual of Mental Disorders (Fifth ed.). Arlington, VA: American Psychiatric Publishing. pp. 5–25. ISBN 978-0-89042-555-8.
- "The ICD-10 Classification of Mental and Behavioural Disorders" (PDF). World Health Organization. p. 26.
- Heinz A, Voss M, Lawrie SM, Mishara A, Bauer M, Gallinat J, et al. (September 2016). "Shall we really say goodbye to first rank symptoms?". European Psychiatry. 37: 8–13. doi:10.1016/j.eurpsy.2016.04.010. PMID 27429167.
- Schneider, K. Clinical Psychopathology. New York: Grune and Stratton. 1959.
- Bertelsen A (2002). "Schizophrenia and related disorders: experience with current diagnostic systems". Psychopathology. 35 (2–3): 89–93. doi:10.1159/000065125. PMID 12145490. S2CID 41076230.
- Soares-Weiser K, Maayan N, Bergman H, Davenport C, Kirkham AJ, Grabowski S, Adams CE (January 2015). "First rank symptoms for schizophrenia". The Cochrane Database of Systematic Reviews. 1: CD010653. doi:10.1002/14651858.CD010653.pub2. PMC 7079421. PMID 25879096.
- As referenced from PMID 23800613, Heckers S, Tandon R, Bustillo J (March 2010). "Catatonia in the DSM--shall we move or not?". Schizophrenia Bulletin (Editorial). 36 (2): 205–7. doi:10.1093/schbul/sbp136. PMC 2833126. PMID 19933711.
- Barch DM, Bustillo J, Gaebel W, Gur R, Heckers S, Malaspina D, et al. (October 2013). "Logic and justification for dimensional assessment of symptoms and related clinical phenomena in psychosis: relevance to DSM-5". Schizophrenia Research. 150 (1): 15–20. doi:10.1016/j.schres.2013.04.027. PMID 23706415. S2CID 10052003.
- "Childhood schizophrenia: Tests and diagnosis". Mayo Clinic. 17 December 2010.
- Hayes, D; Kyriakopoulos, M (August 2018). "Dilemmas in the treatment of early-onset first-episode psychosis". Therapeutic Advances in Psychopharmacology. 8 (8): 231–239. doi:10.1177/2045125318765725. PMC 6058451. PMID 30065814.
- American Psychiatric Association (2013). "Autism Spectrum Disorder. 299.00 (F84.0). Differential Diagnosis". Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Arlington, VA: American Psychiatric Publishing. p. 58. doi:10.1176/appi.books.9780890425596. hdl:2027.42/138395. ISBN 978-0-89042-559-6.
- Sawant, Neena Sanjiv; Parkar, Shubhangi; Kulkarni, Prathamesh (2014-08-30). "Childhood disintegrative disorder misdiagnosed as childhood-onset schizophrenia". South African Journal of Psychiatry. 20 (3): 2. doi:10.4102/sajpsychiatry.v20i3.518. ISSN 2078-6786.
- Wicks-Nelson R, Israel AC (2009). "Pervasive developmental disorders and schizophrenia". In Jewell L (ed.). Abnormal child and adolescent psychology. Upper Saddle River, NJ: Prentice Hall Higher Education. pp. 327–359. ISBN 978-0-13-235978-8.
- Kennedy E, Kumar A, Datta SS (September 2007). "Antipsychotic medication for childhood-onset schizophrenia". Schizophrenia Bulletin. 33 (5): 1082–3. doi:10.1093/schbul/sbm080. PMC 2632357. PMID 17670793.
- Cohen D, Bonnot O, Bodeau N, Consoli A, Laurent C (June 2012). "Adverse effects of second-generation antipsychotics in children and adolescents: a Bayesian meta-analysis". Journal of Clinical Psychopharmacology. 32 (3): 309–16. doi:10.1097/JCP.0b013e3182549259. PMID 22544019. S2CID 5920580.
- Kumar A, Datta SS, Wright SD, Furtado VA, Russell PS (October 2013). "Atypical antipsychotics for psychosis in adolescents". The Cochrane Database of Systematic Reviews. 10 (10): CD009582. doi:10.1002/14651858.CD009582.pub2. PMID 24129841.
- Madaan V, Dvir Y, Wilson DR (August 2008). "Child and adolescent schizophrenia: pharmacological approaches". Expert Opinion on Pharmacotherapy. Informa Healthcare. 9 (12): 2053–68. doi:10.1517/146565184.108.40.2063. PMID 18671461. S2CID 71397213.
- Clemmensen L, Vernal DL, Steinhausen HC (September 2012). "A systematic review of the long-term outcome of early onset schizophrenia". BMC Psychiatry. 12: 150. doi:10.1186/1471-244X-12-150. PMC 3521197. PMID 22992395.
- Vita A, De Peri L, Deste G, Barlati S, Sacchetti E (September 2015). "The Effect of Antipsychotic Treatment on Cortical Gray Matter Changes in Schizophrenia: Does the Class Matter? A Meta-analysis and Meta-regression of Longitudinal Magnetic Resonance Imaging Studies". Biological Psychiatry. 78 (6): 403–12. doi:10.1016/j.biopsych.2015.02.008. PMID 25802081. S2CID 27008041.
- Navari S, Dazzan P (November 2009). "Do antipsychotic drugs affect brain structure? A systematic and critical review of MRI findings". Psychological Medicine. 39 (11): 1763–77. doi:10.1017/S0033291709005315. PMID 19338710. S2CID 4919922.
- Gonthier M, Lyon MA (22 July 2004). "Childhood-Onset Schizophrenia: An Overview". Psychology in the Schools. 41 (7): 803–811. doi:10.1002/pits.20013.
- Richard Noll (2009). The Encyclopedia of Schizophrenia and Other Psychotic Disorders. Infobase Publishing. p. 131. ISBN 978-0-8160-7508-9.
- Robert Jean Campbell (2009). Campbell's Psychiatric Dictionary. Oxford University Press. pp. 265–266. ISBN 978-0-19-534159-1.
- Dirk Marcel Dhossche (2006). Catatonia in Autism Spectrum Disorders. Elsevier. pp. 4–5. ISBN 978-0-08-046338-4.
- "ICD-11 - Mortality and Morbidity Statistics". icd.who.int. Retrieved 27 November 2020.
- Leonhard K (1995). Classification of Endogeneous Psychoses and their Differentiated Etiology (2nd ed.). Springer Science & Business Media. p. 335. ISBN 3-211-83259-9. Retrieved 25 September 2018.
- Tiffin PA, Welsh P (November 2013). "Practitioner review: schizophrenia spectrum disorders and the at-risk mental state for psychosis in children and adolescents--evidence-based management approaches". Journal of Child Psychology and Psychiatry, and Allied Disciplines. 54 (11): 1155–75. doi:10.1111/jcpp.12136. PMID 24102356.