|Classification and external resources|
Anxiety disorders are a category of mental disorders characterized by feelings of anxiety and fear, where anxiety is a worry about future events and fear is a reaction to current events. These feelings may cause physical symptoms, such as a racing heart and shakiness. There are a number of anxiety disorders: including generalized anxiety disorder, a specific phobia, social anxiety disorder, separation anxiety disorder, agoraphobia, and panic disorder among others. While each has its own characteristics and symptoms, they all include symptoms of anxiety.
Anxiety disorders are partly genetic but may also be due to drug use including alcohol and caffeine, as well as withdrawal from certain drugs. They often occur with other mental disorders, particularly major depressive disorder, bipolar disorder, certain personality disorders, and eating disorders. The term anxiety covers four aspects of experiences that an individual may have: mental apprehension, physical tension, physical symptoms and dissociative anxiety. The emotions present in anxiety disorders range from simple nervousness to bouts of terror. There are other psychiatric and medical problems that may mimic the symptoms of an anxiety disorder, such as hyperthyroidism.
Common treatment options include lifestyle changes, therapy, and medications. Medications are typically recommended only if other measures are not effective. Anxiety disorders occur about twice as often in females as males, and generally begin during childhood. As many as 18% of Americans and 14% of Europeans may be affected by one or more anxiety disorders.
- 1 Classification
- 2 Causes
- 3 Mechanisms
- 4 Prevention
- 5 Diagnosis
- 6 Treatment
- 7 Prognosis
- 8 Epidemiology
- 9 References
- 10 Further reading
- 11 External links
Generalized anxiety disorder (GAD) is a common, chronic disorder characterized by long-lasting anxiety that is not focused on any one object or situation. Those suffering from generalized anxiety disorder experience non-specific persistent fear and worry, and become overly concerned with everyday matters. According to Schacter, Gilbert, and Wegner's book Psychology: Second Edition, generalized anxiety disorder is "characterized by chronic excessive worry accompanied by three or more of the following symptoms: restlessness, fatigue, concentration problems, irritability, muscle tension, and sleep disturbance". Generalized anxiety disorder is the most common anxiety disorder to affect older adults. Anxiety can be a symptom of a medical or substance abuse problem, and medical professionals must be aware of this. A diagnosis of GAD is made when a person has been excessively worried about an everyday problem for six months or more. A person may find that he/she has problems making daily decisions and remembering commitments as a result of lack of concentration/preoccupation with worry. Appearance looks strained, with increased sweating from the hands, feet, and axillae, and he/she may be tearful, which can suggest depression. Before a diagnosis of anxiety disorder is made, physicians must rule out drug-induced anxiety and other medical causes.
The single largest category of anxiety disorders is that of phobic disorders, which includes all cases in which fear and anxiety is triggered by a specific stimulus or situation. Between 5% and 12% of the population worldwide suffer from phobic disorders. Sufferers typically anticipate terrifying consequences from encountering the object of their fear, which can be anything from an animal to a location to a bodily fluid to a particular situation. Sufferers understand that their fear is not proportional to the actual potential danger but still are overwhelmed by it.
With panic disorder, a person has brief attacks of intense terror and apprehension, often marked by trembling, shaking, confusion, dizziness, nausea, and/or difficulty breathing. These panic attacks, defined by the APA as fear or discomfort that abruptly arises and peaks in less than ten minutes, can last for several hours. Attacks can be triggered by stress, fear, or even exercise; the specific cause is not always apparent.
In addition to recurrent unexpected panic attacks, a diagnosis of panic disorder requires that said attacks have chronic consequences: either worry over the attacks' potential implications, persistent fear of future attacks, or significant changes in behavior related to the attacks. As such, those suffering from panic disorder experience symptoms even outside specific panic episodes. Often, normal changes in heartbeat are noticed by a panic sufferer, leading them to think something is wrong with their heart or they are about to have another panic attack. In some cases, a heightened awareness (hypervigilance) of body functioning occurs during panic attacks, wherein any perceived physiological change is interpreted as a possible life-threatening illness (i.e., extreme hypochondriasis).
Agoraphobia is the specific anxiety about being in a place or situation where escape is difficult or embarrassing or where help may be unavailable. Agoraphobia is strongly linked with panic disorder and is often precipitated by the fear of having a panic attack. A common manifestation involves needing to be in constant view of a door or other escape route. In addition to the fears themselves, the term agoraphobia is often used to refer to avoidance behaviors that sufferers often develop. For example, following a panic attack while driving, someone suffering from agoraphobia may develop anxiety over driving and will therefore avoid driving. These avoidance behaviors can often have serious consequences.
Social anxiety disorder
Social anxiety disorder (SAD; also known as social phobia) describes an intense fear and avoidance of negative public scrutiny, public embarrassment, humiliation, or social interaction. This fear can be specific to particular social situations (such as public speaking) or, more typically, is experienced in most (or all) social interactions. Social anxiety often manifests specific physical symptoms, including blushing, sweating, and difficulty speaking. As with all phobic disorders, those suffering from social anxiety often will attempt to avoid the source of their anxiety; in the case of social anxiety this is particularly problematic, and in severe cases can lead to complete social isolation.
Obsessive–compulsive disorder (OCD) is a type of anxiety disorder primarily characterized by repetitive obsessions (distressing, persistent, and intrusive thoughts or images) and compulsions (urges to perform specific acts or rituals). It affects roughly 3% of the population worldwide. The OCD thought pattern may be likened to superstitions insofar as it involves a belief in a causative relationship where, in reality, one does not exist. Often the process is entirely illogical; for example, the compulsion of walking in a certain pattern may be employed to alleviate the obsession of impending harm. And in many cases, the compulsion is entirely inexplicable, simply an urge to complete a ritual triggered by nervousness.
In a slight minority of cases, sufferers of OCD may only experience obsessions, with no overt compulsions; a much smaller number of sufferers experience only compulsions.
Post-traumatic stress disorder
Post-traumatic stress disorder (PTSD) is an anxiety disorder that results from a traumatic experience. Post-traumatic stress can result from an extreme situation, such as combat, natural disaster, rape, hostage situations, child abuse, bullying, or even a serious accident. It can also result from long-term (chronic) exposure to a severe stressor, for example soldiers who endure individual battles but cannot cope with continuous combat. Common symptoms include hypervigilance, flashbacks, avoidant behaviors, anxiety, anger and depression. There are a number of treatments that form the basis of the care plan for those suffering with PTSD. Such treatments include cognitive behavioral therapy (CBT), psychotherapy and support from family and friends.
Separation anxiety disorder (SepAD) is the feeling of excessive and inappropriate levels of anxiety over being separated from a person or place. Separation anxiety is a normal part of development in babies or children, and it is only when this feeling is excessive or inappropriate that it can be considered a disorder. Separation anxiety disorder affects roughly 7% of adults and 4% of children, but the childhood cases tend to be more severe; in some instances, even a brief separation can produce panic.
Situational anxiety is caused by new situations or changing events. It can also be caused by various events that make that particular individual uncomfortable. Its occurrence is very common. Often, an individual will experience panic attacks or extreme anxiety in specific situations. A situation that causes one individual to experience anxiety may not affect another individual at all. For example, some people become uneasy in crowds or tight spaces, so standing in a tightly packed line, say at the bank or a store register, may cause them to experience extreme anxiety, possibly a panic attack. Others, however, may experience anxiety when major changes in life occur, such as entering college, getting married, having children, etc.
Children experience anxiety disorders similar to adults.
A common anxiety disorder in children is school phobia, which in some cases can be a type of separation anxiety. Sometimes the anxiety has no obvious cause. In other instances, the child may experience bullying from classmates, or even a teacher. They could also be stressed from the workload they are given. School phobia may also be a form of social phobia, also known as social anxiety. Children with this disorder may avoid speaking in front of their classmates or meeting new people. Typically, social phobia in children is caused by some traumatic event, such as not knowing an answer when called on in class.
The symptoms for both disorders are the same in children as they are in adults. If a child has GAD, they may worry about anything, even if it is seemingly minor. They long for attention, approval, and encouragement from others. The only difference is they are more likely to worry about things that relate to them. Those things may include grades, bullies, getting hurt, storms, etc. The symptoms of OCD include repetitive and/or compulsive behaviors.
Anxiety and depression can be caused by alcohol abuse, which in most cases improves with prolonged abstinence. Even moderate, sustained alcohol use may increase anxiety levels in some individuals. Caffeine, alcohol and benzodiazepine dependence can worsen or cause anxiety and panic attacks. Anxiety commonly occurs during the acute withdrawal phase of alcohol and can persist for up to 2 years as part of a post-acute withdrawal syndrome, in about a quarter of people recovering from alcoholism. In one study in 1988–1990, illness in approximately half of patients attending mental health services at one British hospital psychiatric clinic, for conditions including anxiety disorders such as panic disorder or social phobia, was determined to be the result of alcohol or benzodiazepine dependence. In these patients, an initial increase in anxiety occurred during the withdrawal period followed by a cessation of their anxiety symptoms.
There is evidence that chronic exposure to organic solvents in the work environment can be associated with anxiety disorders. Painting, varnishing and carpet-laying are some of the jobs in which significant exposure to organic solvents may occur.
Ingestion of caffeine may cause or exacerbate anxiety disorders. A number of clinical studies have shown a positive association between caffeine and anxiogenic effects and/or panic disorder. Those with anxiety can have high caffeine sensitivity.
Anxiety disorders can arise in response to life stresses such as financial worries or chronic physical illness. Anxiety is also common among older people who have dementia. On the other hand, anxiety disorder is sometimes misdiagnosed among older adults when doctors misinterpret symptoms of a physical ailment (for instance, racing heartbeat due to cardiac arrhythmia) as signs of anxiety.
GAD runs in families and is six times more common in the children of someone with the condition.
While anxiety arose as an adaptation, in modern times it is almost always thought of negatively in the context of anxiety disorders. People with these disorders have highly sensitive systems; hence, their systems tend to overreact to seemingly harmless stimuli. Sometimes anxiety disorders occur in those who have had traumatic youths, demonstrating an increased prevalence of anxiety when it appears a child will have a difficult future. In these cases, the disorder arises as a way to predict that the individual’s environment will continue to pose threats.
Persistence of anxiety
At a low level, anxiety is not a bad thing. In fact, the hormonal response to anxiety has evolved as a benefit, as it helps humans react to dangers. Researchers in evolutionary medicine believe this adaptation allows humans to realize there is a potential threat and to act accordingly in order to ensure greatest possibility of protection. It has actually been shown that those with low levels of anxiety have a greater risk of death than those with average levels. This is because the absence of fear can lead to injury or death. Additionally, patients with both anxiety and depression were found to have lower morbidity than those with depression alone. The functional significance of the symptoms associated with anxiety includes: greater alertness, quicker preparation for action, and reduced probability of missing threats. In the wild, vulnerable individuals, for example those who are hurt or pregnant, have a lower threshold for anxiety response, making them more alert. This demonstrates a lengthy evolutionary history of the anxiety response.
It has been theorized that high rates of anxiety are a reaction to how the social environment has changed from the Paleolithic era. For example, in the Stone Age there was greater skin-to-skin contact and more handling of babies by their mothers, both of which are strategies that reduce anxiety. Additionally, there is greater interaction with strangers in present times as opposed to interactions solely between close-knit tribes. Researchers posit that the lack of constant social interaction, especially in the formative years, is a driving cause of high rates of anxiety.
Many current cases are likely to have resulted from an evolutionary mismatch, which has been specifically been termed a “psychopathogical mismatch.” In evolutionary terms, a mismatch occurs when an individual possesses traits that were adapted for an environment that differs from the individual’s current environment. For example, even though an anxiety reaction may have been evolved to help with life-threatening situations, for highly sensitized individuals in Westernized cultures simply hearing bad news can elicit a strong reaction.
An evolutionary perspective may provide insight into alternatives to current clinical treatment methods for anxiety disorders. Simply knowing some anxiety is beneficial may alleviate some of the panic associated with mild conditions. Some researchers believe that, in theory, anxiety can be mediated by reducing a patient’s feeling of vulnerability and then changing their appraisal of the situation.
Low levels of GABA, a neurotransmitter that reduces activity in the central nervous system, contribute to anxiety. A number of anxiolytics achieve their effect by modulating the GABA receptors.
People with obsessive-compulsive disorder (sometimes considered an anxiety disorder), have increased grey matter volumes in bilateral lenticular nuclei, extending to the caudate nuclei, while decreased grey matter volumes in bilateral dorsal medial frontal/anterior cingulate gyri. These findings contrast with those in people with other anxiety disorders, who have decreased (rather than increased) grey matter volumes in bilateral lenticular/caudate nuclei while also decreased grey matter volumes in bilateral dorsal medial frontal/anterior cingulate gyri. Alterations of circadian rhythms associated with obsessive-compulsive disorder have recently come into the focus of research.
The amygdala is central to the processing of fear and anxiety, and its function may be disrupted in anxiety disorders. Sensory information enters the amygdala through the nuclei of the basolateral complex (consisting of lateral, basal, and accessory basal nuclei). The basolateral complex processes sensory-related fear memories and communicates their threat importance to memory and sensory processing elsewhere in the brain, such as the medial prefrontal cortex and sensory cortices.
Another important area is the adjacent central nucleus of the amygdala, which controls species-specific fear responses, via connections to the brainstem, hypothalamus, and cerebellum areas. In those with general anxiety disorder, these connections functionally seem to be less distinct, with greater gray matter in the central nucleus. Another difference is that the amygdala areas have decreased connectivity with the insula and cingulate areas that control general stimulus salience, while having greater connectivity with the parietal cortex and prefrontal cortex circuits that underlie executive functions.
The latter suggests a compensation strategy for dysfunctional amygdala processing of anxiety. Researchers have noted "Amygdalofrontoparietal coupling in generalized anxiety disorder patients may ... reflect the habitual engagement of a cognitive control system to regulate excessive anxiety." This is consistent with cognitive theories that suggest the use in this disorder of attempts to reduce the involvement of emotions with compensatory cognitive strategies.
Clinical and animal studies suggest a correlation between anxiety disorders and difficulty in maintaining balance. A possible mechanism is malfunction in the parabrachial area, a brain structure that, among other functions, coordinates signals from the amygdala with input concerning balance.
Anxiety processing in the basolateral amygdala has been implicated with dendritic arborization of the amygdaloid neurons. SK2 potassium channels mediate inhibitory influence on action potentials and reduce arborization. By overexpressing SK2 in the basolateral amygdala, anxiety in experimental animals can be reduced together with general levels of stress-induced corticosterone secretion.
Focus is increasing on prevention of anxiety disorders. There is tentative evidence to support the use of cognitive behavior therapy and mindfulness therapy. As of 2013 there are no effective measures to prevent GAD in adults.
Anxiety disorders are often severe chronic conditions, which can be present from an early age or begin suddenly after a triggering event. They are prone to flare up at times of high stress and are frequently accompanied by physiological symptoms such as headache, sweating, muscle spasms, tachycardia, palpitations, and hypertension, which in some cases lead to fatigue or exhaustion.
In casual discourse the words "anxiety" and "fear" are often used interchangeably; in clinical usage, they have distinct meanings: "anxiety" is defined as an unpleasant emotional state for which the cause is either not readily identified or perceived to be uncontrollable or unavoidable, whereas "fear" is an emotional and physiological response to a recognized external threat. The term "anxiety disorder" includes fears (phobias) as well as anxieties.[medical citation needed]
Standardized screening clinical questionnaires such as the Taylor Manifest Anxiety Scale or the Zung Self-Rating Anxiety Scale can be used to detect anxiety symptoms, and suggest the need for a formal diagnostic assessment of anxiety disorder.
Anxiety disorders often occur along with other mental disorders, in particular depression, which may occur in as many as 60% of people with anxiety disorders. The fact that there is considerable overlap between symptoms of anxiety and depression, and that the same environmental triggers can provoke symptoms in either condition, may help to explain this high rate of comorbidity.
Studies have also indicated that anxiety disorders are more likely among those with family history of anxiety disorders, especially certain types.
Sexual dysfunction often accompanies anxiety disorders, although it is difficult to determine whether anxiety causes the sexual dysfunction or whether they arise from a common cause. The most common manifestations in individuals with anxiety disorder are avoidance of intercourse, premature ejaculation or erectile dysfunction among men and pain during intercourse among women. Sexual dysfunction is particularly common among people affected by panic disorder (who may fear that a panic attack will occur during sexual arousal) and posttraumatic stress disorder.
Treatment options available include lifestyle changes, therapy, and medications. Medication are only recommended if other measures are not effective. Stopping smoking has benefits in anxiety as large as or larger than those of medications.
Cognitive behavioral therapy (CBT) is effective for anxiety disorders. CBT, as its name suggests, has two main components: cognitive and behavioral. In cases of social anxiety, the cognitive component can help the person question how they can be so sure that others are continually watching and harshly judging him or her. The behavioral component seeks to change people's reactions to anxiety-provoking situations.
CBT appears to be equally effective when carried out via the internet.
As such it serves as a logical extension of cognitive therapy, whereby people are shown proof in the real world that their dysfunctional thought processes are unrealistic. A key element of this component is gradual exposure, in which the patient is confronted by the things they fear in a structured, sensitive manner. Gradual exposure is an inherently unpleasant technique; ideally it involves exposure to a feared social situation that is anxiety provoking but bearable, for as long as possible, two to three times a week. Often, a hierarchy of feared steps is constructed and the patient is exposed to each step sequentially.
The aim is to learn from acting differently and observing reactions. This is intended to be done with support and guidance, and when the therapist and patient feel they are ready. Cognitive-behavioral therapy for social phobia also includes anxiety management training, which may include techniques such as deep breathing and muscle relaxation exercises, which may be practiced 'in-situ'. CBT can also be conducted partly in group sessions, facilitating the sharing of experiences, a sense of acceptance by others and undertaking behavioral challenges in a trusted environment (Heimberg).
Some studies have suggested social skills training can help with social anxiety. However, it is not clear whether specific social skills techniques and training are required, rather than just support with general social functioning and exposure to social situations. Additionally, a recent study has suggested that interpersonal therapy, a form of psychotherapy primarily used to treat depression, may also be effective in the treatment of social phobia.
In social phobia a specific form of short-term CBT, the central component being gradual exposure therapy. Self-help books can contribute to the treatment of people with anxiety disorders.
Medication are only indicated if other measures have not been found to be effective or a person is not interested in trying them. If medications are used SSRIs are recommended as first-line agents. Benzodiazepines are also sometimes indicated for short-term or "as needed" use. They are usually considered second-line due to disadvantages such as cognitive impairment and risks of dependence. MAOIs such as phenelzine and tranylcypromine are considered an effective treatment and are especially useful in treatment-resistant cases, however, dietary restrictions and medical interactions may limit their use. Pregabalin may be effective. In children and adolescents, when a medication option is warranted, antidepressants such as SSRIs, SNRIs as well as tricyclic antidepressants can be effective. Buspar is not effective in children and adolescents who have an anxiety disorder.
These medications need to be used with care among older adults, who are more likely to have side effects because of coexisting physical disorders. Adherence problems are more likely among elderly patients, who may have difficulty understanding, seeing, or remembering instructions.
The effectiveness and increased suicide risk of SSRIs has been subject to controversy. General side effects are common and may include headaches, nausea, insomnia, and changes in sexual behavior. Treatment safety during pregnancy has not been established. In late 2004 much media attention was given to a proposed link between SSRI use and suicide. For this reason, the use of SSRIs in pediatric cases of depression is recognized by the Food and Drug Administration as warranting a cautionary statement to the parents of children who may be prescribed SSRIs.
The atypical antipsychotic quetiapine appears effective in generalized anxiety disorder, however rates of adverse effects is greater than that with SSRIs. Evidence for risperidone and olanzapine is not enough to make any comments. For OCD the evidence for risperidone and quetiapine is tentative with insufficient evidence for olanzapine.
Benzodiazepines are an alternative to SSRIs. These drugs are often used for short-term relief of severe, disabling anxiety. Although benzodiazepines are still sometimes prescribed for long-term everyday use, there is concern over the development of drug tolerance, dependency and recreational abuse. It has been recommended that benzodiazepines only be considered for individuals who fail to respond to safer medications. Effects usually begin to appear within minutes or hours. Benzodiazepines are not however, effective in the treatment of children and adolescents who have an anxiety disorder.
Some people with a form of social phobia called performance phobia have been helped by beta-blockers. Taken in low doses, they control the physical manifestation of anxiety and can be taken before a public performance.[medical citation needed]
Treatment controversy arises because while some studies indicate that a combination of medication and psychotherapy can be more effective than either one alone, others suggest pharmacological interventions are largely palliative, and can actually interfere with the mechanisms of successful therapy. Psychotherapeutic interventions have better long-term efficacy compared to pharmacotherapy.
Caffeine can cause anxiety, along with more minor effects such as muscle twitching, hand tremors, and headaches. The best way to prevent caffeinism is to either wean off of caffeine completely or reduce consumption. For some people, anxiety can be reduced by coming off caffeine. Anxiety can temporarily increase during caffeine withdrawal.
Regular exercise and reducing caffeine are often useful in treating anxiety. There is tentative evidence that yoga may be effective. Evidence is insufficient regarding meditation to make any conclusions.
Many other remedies have been used for anxiety disorder. These include kava, where the potential for benefit seems greater than that for harm with short-term use in those with mild to moderate anxiety. The American Academy of Family Physicians (AAFP) recommends use of kava for those with mild to moderate anxiety disorders who are not using alcohol or taking other medicines metabolized by the liver, but who wish to use "natural" remedies. Side effects of kava in the clinical trials were rare and mild.
Inositol has been found to have modest effects in people with panic disorder or obsessive-compulsive disorder. There is insufficient evidence to support the use of St. John's wort, valerian or passionflower.
Several methods of treatment have been found to be effective in treating childhood anxiety disorders. Like adults, children may undergo psychotherapy, cognitive-behavioral therapy, or counseling. They may still be given medication such as SSRIs, but in much smaller doses. However, administering potent medications like antidepressants to children is controversial. As a result, other forms of treatment have become increasingly popular. Family therapy is a form of treatment in which the child meets with a therapist together with the primary guardians and siblings. Each family member may attend individual therapy, but family therapy is typically a form of group therapy. Art and play therapy are also used. Art therapy is most commonly used when the child will not or cannot verbally communicate, due to trauma or a disability in which they are nonverbal. Participating in art activities allows the child to express what they otherwise may not be able to communicate to others. In play therapy, the child is allowed to play however they please as a therapist observes them. The therapist may intercede from time to time with a question, comment, or suggestion. This is often most effective when the family of the child plays a significant role in the treatment.
If these children are left untreated, they face risks such as poor results at school, avoidance of important social activities, and substance abuse. Children who have an anxiety disorder are likely to have other disorders such as depression, eating disorders, attention deficit disorders both hyperactive and inattentive.
In Europe, Africa and Asia, lifetime rates of anxiety disorders are between 9 and 16%, and yearly rates are between 4 and 7%. In the United States, the lifetime prevalence of anxiety disorders is about 29% and between 11 and 18% of adults have the condition in a given year. This difference is affected by the range of ways in which different cultures interpret anxiety symptoms and what they consider to be normative behavior. In general, anxiety disorders represent the most prevalent psychiatric condition in the United States, outside of substance use disorder.
- Diagnostic and Statistical Manual of Mental DisordersAmerican Psychiatric Associati. (5th ed. ed.). Arlington: American Psychiatric Publishing. 2013. pp. 189–195. ISBN 978-0890425558.
- Diagnostic and statistical manual of mental disorders : DSM-5 (5th ed. ed.). Washington [etc.]: American Psychiatric Publishing. 2013. pp. 189–233. ISBN 0890425558.
- Psychiatry, Michael Gelder, Richard Mayou, John Geddes 3rd ed. Oxford; New York: Oxford University Press, c 2005 p. 75
- David Healy, Drugs Explained, Section 5: Management of Anxiety, Elsevier Health Sciences, 2008, pp. 136–137
- Phil Barker (7 October 2003). Psychiatric and mental health nursing: the craft of caring. London: Arnold. ISBN 978-0-340-81026-2. Retrieved 17 December 2010.
- Patel, G; Fancher, TL (Dec 3, 2013). "In the clinic. Generalized anxiety disorder.". Annals of internal medicine 159 (11): ITC6–1, ITC6–2, ITC6–3, ITC6–4, ITC6–5, ITC6–6, ITC6–7, ITC6–8, ITC6–9, ITC6–10, ITC6–11; quiz ITC6–12. doi:10.7326/0003-4819-159-11-201312030-01006. PMID 24297210.
- Kessler RC, Chiu WT, Demler O, Merikangas KR, Walters EE (June 2005). "Prevalence, severity, and comorbidity of 12-month DSM-IV disorders in the National Comorbidity Survey Replication". Arch. Gen. Psychiatry 62 (6): 617–627. doi:10.1001/archpsyc.62.6.617. PMC 2847357. PMID 15939839.
- Schacter, D. L., Gilbert, D. T., & Wegner, D.M. (2011). Psychology: Second Edition. New York, NY: Worth.
- Calleo J, Stanley M (2008). "Anxiety Disorders in Later Life: Differentiated Diagnosis and Treatment Strategies". Psychiatric Times 26 (8).
- Psychology, Michael Passer, Ronald Smith, Nigel Holt, Andy Bremner, Ed Sutherland, Michael Vliek (2009) McGrath Hill Education, UK: McGrath Hill Companies Inc. p 790
- Varcarolis. E (2010). Manual of Psychiatric Nursing Care Planning: Assessment Guides, Diagnoses and Psychopharmacology. 4th ed. New York: Saunders Elsevier. p 109.
- Keeton, CP; Kolos, AC; Walkup, JT (2009). "Pediatric generalized anxiety disorder: epidemiology, diagnosis, and management.". Paediatric drugs 11 (3): 171–83. doi:10.2165/00148581-200911030-00003. PMID 19445546.
- Psychology. Michael Passer, Ronald Smith, Nigel Holt, Andy Bremner, Ed Sutherland, Michael Vliek. (2009) McGrath Hill Higher Education; UK: McGrath Hill companies Inc.
- Craske 2003 Gorman, 2000
- Psychological Disorders, Psychologie Anglophone
- Post-Traumatic Stress Disorder and the Family. Veterans Affairs Canada. 2006. ISBN 0-662-42627-4.
- Siegler, Robert (2006). How Children Develop, Exploring Child Develop Student Media Tool Kit & Scientific American Reader to Accompany How Children Develop. New York: Worth Publishers. ISBN 0-7167-6113-0.
- "Adult Separation Anxiety Often Overlooked Diagnosis – Arehart-Treichel 41 (13): 30 – Psychiatr News". Pn.psychiatryonline.org. Retrieved 2012-02-20.
- Shear, K.; Jin, R.; Ruscio, AM.; Walters, EE.; Kessler, RC. (Jun 2006). "Prevalence and correlates of estimated DSM-IV child and adult separation anxiety disorder in the National Comorbidity Survey Replication". Am J Psychiatry 163 (6): 1074–1083. doi:10.1176/appi.ajp.163.6.1074. PMC 1924723. PMID 16741209.
- Situational Panic Attacks. (n.d.). Retrieved from http://www.sound-mind.org/situational-panic-attacks.html
- Biegel, D.E. (1995). Caregiver burden. In G.E. Maddox (Ed.), The encyclopedia of aging (2,d ed., pp. 138-141). New York: Springer
- Harvard Medical School (2004a). "December). Children's fears and anxieties". Harvard Mental Health Letter 21 (6): 1–3.
- Evans, Katie; Sullivan, Michael J. (1 March 2001). Dual Diagnosis: Counseling the Mentally Ill Substance Abuser (2nd ed.). Guilford Press. pp. 75–76. ISBN 978-1-57230-446-8.
- Lindsay, S.J.E.; Powell, Graham E., eds. (28 July 1998). The Handbook of Clinical Adult Psychology (2nd ed.). Routledge. pp. 152–153. ISBN 978-0-415-07215-1.
- Johnson, Bankole A. (2011). Addiction medicine : science and practice. New York: Springer. pp. 301–303. ISBN 978-1-4419-0337-2.
- Cohen SI (February 1995). "Alcohol and benzodiazepines generate anxiety, panic and phobias". J R Soc Med 88 (2): 73–77. PMC 1295099. PMID 7769598.
- Morrow LA et al. (2000). "Increased incidence of anxiety and depressive disorders in persons with organic solvent exposure". Psychosomat Med 62 (6): 746–750. PMID 11138992.
- Scott, Trudy (2011). The Antianxiety Food Solution: How the Foods You Eat Can Help You Calm Your Anxious Mind, Improve Your Mood, and End Cravings. New Harbinger Publications. p. 59. ISBN 1-57224-926-9. Retrieved October 7, 2012.
- Winston AP (2005). "Neuropsychiatric effects of caffeine". Advances in Psychiatric Treatment 11 (6): 432–439. doi:10.1192/apt.11.6.432.
- Hughes RN (June 1996). "Drugs Which Induce Anxiety: Caffeine". New Zealand Journal of Psychology 25 (1): 36–42. doi:10.1016/S0278-6915(02)00096-0. PMID 12204388.
- Vilarim MM, Rocha Araujo DM, Nardi AE (August 2011). "Caffeine challenge test and panic disorder: a systematic literature review". Expert Rev Neurother 11 (8): 1185–95. doi:10.1586/ern.11.83. PMID 21797659.
- Vilarim, Marina Machado; Rocha Araujo, Daniele Marano; Nardi, Antonio Egidio (2011). "Caffeine challenge test and panic disorder: A systematic literature review". Expert Review of Neurotherapeutics 11 (8): 1185–95. doi:10.1586/ern.11.83. PMID 21797659.
- Bruce, Malcolm; Scott, N; Shine, P; Lader, M (1992). "Anxiogenic Effects of Caffeine in Patients with Anxiety Disorders". Archives of General Psychiatry 49 (11): 867–9. doi:10.1001/archpsyc.1992.01820110031004. PMID 1444724.
- Nardi, Antonio E.; Lopes, Fabiana L.; Valença, Alexandre M.; Freire, Rafael C.; Veras, André B.; De-Melo-Neto, Valfrido L.; Nascimento, Isabella; King, Anna Lucia; Mezzasalma, Marco A.; Soares-Filho, Gastão L.; Zin, Walter A. (2007). "Caffeine challenge test in panic disorder and depression with panic attacks". Comprehensive Psychiatry 48 (3): 257–63. doi:10.1016/j.comppsych.2006.12.001. PMID 17445520.
- Grinde, B (2005). "An approach to the prevention of anxiety-related disorders based on evolutionary medicine". Preventative Medicine 40 (6): 904–909. doi:10.1016/j.ypmed.2004.08.001. PMID 15850894.
- Bateson, M; B. Brilot; D. Nettle (2011). "Anxiety: An evolutionary approach". Canadian Journal of Psychiatry 56 (12): 707–715.
- Price, John S. (September 2003). "Evolutionary aspects of anxiety disorders". Dialogues in Clinical Neuroscience 5 (3): 223–236. PMC 3181631. PMID 22033473.
- Lydiard RB (2003). "The role of GABA in anxiety disorders". J Clin Psychiatry 64 (Suppl 3): 21–27. PMID 12662130.
- Nemeroff CB (2003). "The role of GABA in the pathophysiology and treatment of anxiety disorders". Psychopharmacol Bull 37 (4): 133–146. PMID 15131523.
- Enna SJ (1984). "Role of gamma-aminobutyric acid in anxiety". Psychopathology 17 (Suppl 1): 15–24. doi:10.1159/000284073. PMID 6143341.
- Dunlop BW, Davis PG (2008). "Combination treatment with benzodiazepines and SSRIs for comorbid anxiety and depression: a review". Prim Care Companion J Clin Psychiatry 10 (3): 222–228. doi:10.4088/PCC.v10n0307. PMC 2446479. PMID 18615162.
- Radua, Joaquim; Mataix-Cols, David (November 2009). "Voxel-wise meta-analysis of grey matter changes in obsessive–compulsive disorder". British Journal of Psychiatry 195 (5): 393–402. doi:10.1192/bjp.bp.108.055046. PMID 19880927.
- Radua, Joaquim; van den Heuvel, Odile A.; Surguladze, Simon; Mataix-Cols, David (5 July 2010). "Meta-analytical comparison of voxel-based morphometry studies in obsessive-compulsive disorder vs other anxiety disorders". Archives of General Psychiatry 67 (7): 701–711. doi:10.1001/archgenpsychiatry.2010.70. PMID 20603451.
- Lange K.W. et al. (Oct 2012). Journal of Neural Transmission 119 (10): 1077–83. Missing or empty
- Etkin A, Prater KE, Schatzberg AF, Menon V, Greicius MD (2009). "Disrupted amygdalar subregion functional connectivity and evidence of a compensatory network in generalized anxiety disorder". Arch Gen Psychiatry 66 (12): 1361–1372. doi:10.1001/archgenpsychiatry.2009.104. PMID 19996041.
- Kalueff AV, Ishikawa K, Griffith AJ (2008-01-10). "Anxiety and otovestibular disorders: linking behavioral phenotypes in men and mice". Behav Brain Res. 186 (1): 1–11. doi:10.1016/j.bbr.2007.07.032. PMID 17822783.
- Nagaratnam N, Ip J, Bou-Haidar P (May–June 2005). "The vestibular dysfunction and anxiety disorder interface: a descriptive study with special reference to the elderly". Arch Gerontol Geriatr. 40 (3): 253–264. doi:10.1016/j.archger.2004.09.006. PMID 15814159.
- Lepicard EM, Venault P, Perez-Diaz F, Joubert C, Berthoz A, Chapouthier G (2000-12-20). "Balance control and posture differences in the anxious BALB/cByJ mice compared to the non anxious C57BL/6J mice". Behav Brain Res. 117 (1–2): 185–195. doi:10.1016/S0166-4328(00)00304-1. PMID 11099772.
- Simon NM, Pollack MH, Tuby KS, Stern TA (June 1998). "Dizziness and panic disorder: a review of the association between vestibular dysfunction and anxiety". Ann Clin Psychiatry. 10 (2): 75–80. doi:10.3109/10401239809147746. PMID 9669539.
- Balaban CD, Thayer JF (January–April 2001). "Neurological bases for balance-anxiety links". J Anxiety Disord. 15 (1–2): 53–79. doi:10.1016/S0887-6185(00)00042-6. PMID 11388358.
- Mitra R, Ferguson D, Sapolsky RM (2009-02-10). "SK2 potassium channel overexpression in basolateral amygdala reduces anxiety, stress-induced corticosterone secretion and dendritic arborization". Mol. Psychiatry 14 (9): 847–855, 827. doi:10.1038/mp.2009.9. PMC 2763614. PMID 19204724.
- Bienvenu, OJ; Ginsburg, GS (December 2007). "Prevention of anxiety disorders". International review of psychiatry (Abingdon, England) 19 (6): 647–54. doi:10.1080/09540260701797837. PMID 18092242.
- Khoury B, Lecomte T, Fortin G, et al. (Aug 2013). "Mindfulness-based therapy: a comprehensive meta-analysis". Clin Psychol Rev. 33 (6): 763–71.
- Sharma M, Rush SE (Jul 2014). "Mindfulness-based stress reduction as a stress management intervention for healthy individuals: a systematic review". J Evid Based Complementary Altern Med 19 (4): 271–86. doi:10.1177/2156587214543143.
- Patel, G; Fancher, TL (3 December 2013). "In the clinic. Generalized anxiety disorder.". Annals of internal medicine 159 (11): ITC6–1, ITC6–2, ITC6–3, ITC6–4, ITC6–5, ITC6–6, ITC6–7, ITC6–8, ITC6–9, ITC6–10, ITC6–11; quiz ITC6–12. PMID 24297210.
currently there is no evidence on the effectiveness of preventive measures for GAD in adult
- Zung WW (1971). "A rating instrument for anxiety disorders". Psychosomatics 12 (6): 371–379. doi:10.1016/S0033-3182(71)71479-0. PMID 5172928.
- Cameron OG (December 1, 2007). "Understanding Comorbid Depression and Anxiety". Psychiatric Times 24 (14).
- McLaughlin K; Behar E; Borkovec T (August 25, 2005). "Family history of psychological problems in generalized anxiety disorder". Journal of Clinical Psychology 64 (7): 905–918. doi:10.1002/jclp.20497. PMID 18509873.
- Coretti G, Baldi I (August 1, 2007). "The Relationship Between Anxiety Disorders and Sexual Dysfunction". Psychiatric Times 24 (9).
- Taylor, G.; McNeill, A.; Girling, A.; Farley, A.; Lindson-Hawley, N.; Aveyard, P. (13 February 2014). "Change in mental health after smoking cessation: systematic review and meta-analysis". BMJ 348 (feb13 1): g1151–g1151. doi:10.1136/bmj.g1151. PMC 3923980. PMID 24524926.
- Cuijpers, P; Sijbrandij, M; Koole, S; Huibers, M; Berking, M; Andersson, G (Mar 2014). "Psychological treatment of generalized anxiety disorder: A meta-analysis.". Clinical Psychology Review 34 (2): 130–140. doi:10.1016/j.cpr.2014.01.002. PMID 24487344.
- Otte, C (2011). "Cognitive behavioral therapy in anxiety disorders: current state of the evidence.". Dialogues in clinical neuroscience 13 (4): 413–21. PMC 3263389. PMID 22275847.
- Mewton, L; Smith, J; Rossouw, P; Andrews, G (2014). "Current perspectives on Internet-delivered cognitive behavioral therapy for adults with anxiety and related disorders.". Psychology research and behavior management 7: 37–46. doi:10.2147/PRBM.S40879. PMC 3913603. PMID 24511246.
- Mersch et al., 1991
- Stravynski & Amado, 2001
- Lipsitz et al., 1999
- Warren Mansell (2007-06-01). "Reading about self-help books on cognitive-behavioural therapy for anxiety disorders". Pb.rcpsych.org. Retrieved 2012-02-20.
- Roemer L, Williston SK, Eustis EH (Nov 2013). "Mindfulness and acceptance-based behavioral therapies for anxiety disorders". Curr Psychiatry Rep 15 (11): 410. doi:10.1007/s11920-013-0410-3.
- Lang AJ (May 2013). "What mindfulness brings to psychotherapy for anxiety and depression". Depress Anxiety 30 (5): 409–12. doi:10.1002/da.22081.
- Stein, Dan J (16 February 2004). Clinical Manual of Anxiety Disorders (1st ed.). USA: American Psychiatric Press Inc. p. 7. ISBN 978-1-58562-076-0.
- "Stahl's Essential Psychopharmacology - Cambridge University Press". Stahlonline.cambridge.org. Retrieved 2012-02-20.
- "Stahl's Essential Psychopharmacology - Cambridge University Press". Stahlonline.cambridge.org. Retrieved 2012-02-20.
- Baldwin, DS; Ajel, K; Masdrakis, VG; Nowak, M; Rafiq, R (2013). "Pregabalin for the treatment of generalized anxiety disorder: an update.". Neuropsychiatric disease and treatment 9: 883–92. doi:10.2147/NDT.S36453. PMC 3699256. PMID 23836974.
- Strawn, JR.; Sakolsky, DJ.; Rynn, MA. (Jul 2012). "Psychopharmacologic treatment of children and adolescents with anxiety disorders". Child Adolesc Psychiatr Clin N Am 21 (3): 527–39. doi:10.1016/j.chc.2012.05.003. PMID 22800992.
- Social Phobia at eMedicine
- Federal Drug and Administration. Class Suicidality Labeling Language for Antidepressants. 2004. Retrieved February 24, 2006.
- Depping, AM; Komossa, K; Kissling, W; Leucht, S (Dec 8, 2010). Leucht, Stefan, ed. "Second-generation antipsychotics for anxiety disorders". Cochrane Database of Systematic Reviews (12): CD008120. doi:10.1002/14651858.CD008120.pub2. PMID 21154392.
- Komossa, K; Depping, AM; Meyer, M; Kissling, W; Leucht, S (Dec 8, 2010). "Second-generation antipsychotics for obsessive compulsive disorder.". The Cochrane database of systematic reviews (12): CD008141. doi:10.1002/14651858.CD008141.pub2. PMID 21154394.
- Westenberg, HG. (Jul 1999). "Facing the challenge of social anxiety disorder". Eur Neuropsychopharmacol. 9 Suppl 3: S93–9. doi:10.1016/S0924-977X(99)00029-2. PMID 10523064.
- Aouizerate, B.; Martin-Guehl, C.; Tignol, J. (2004). "[Neurobiology and pharmacotherapy of social phobia]". Encephale 30 (4): 301–313. doi:10.1016/S0013-7006(04)95442-5. PMID 15538306.
- Hollon S; Stewart O; Strunk D (August 25, 2005). "Enduring effects for Cognitive Behavior Therapy in the Treatment of Depression and Anxiety" (PDF). Annual Review of Psychology 57: 285–315. doi:10.1146/annurev.psych.57.102904.190044. PMID 16318597.
- Gould RA, Otto MW, Pollack MH, Yap L (1997). "Cognitive behavioral and pharmacological treatment of generalized anxiety disorder: A preliminary meta-analysis". Behavior Therapy 28 (2): 285–305. doi:10.1016/S0005-7894(97)80048-2.
- Hire J.N. (1978). "Anxiety and Caffeine". Psychological Reports 1978 (42): 833–834.
- Bruce, M. S.; Lader, M. (February 2009). "Caffeine abstention in the management of anxiety disorders". Psychological Medicine 19 (01): 211–4. doi:10.1017/S003329170001117X. PMID 2727208.
- Prasad, Chandan (2005). Nutritional Neuroscience. CRC Press. p. 351. ISBN 0-415-31599-9. Retrieved October 7, 2012.
- Nehlig, Astrid (2004). Coffee, Tea, Chocolate, and the Brain. CRC Press. p. 136. ISBN 0-415-30691-4. Retrieved October 7, 2012.
- Juliano LM, Griffiths RR (2004). "A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features". Psychopharmacology (Berl.) 176 (1): 1–29. doi:10.1007/s00213-004-2000-x. PMID 15448977.
- Herring, MP; O'Connor, PJ; Dishman, RK (Feb 22, 2010). "The effect of exercise training on anxiety symptoms among patients: a systematic review.". Archives of Internal Medicine 170 (4): 321–31. doi:10.1001/archinternmed.2009.530. PMID 20177034.
- American Psychiatric Association. (1994). Diagnostic and Statistical Manual of Mental Disorders (4th ed.). American Psychiatric Association. ISBN 0-89042-062-9.
- Li, AW; Goldsmith, CA (March 2012). "The effects of yoga on anxiety and stress". Alternative medicine review : a journal of clinical therapeutic 17 (1): 21–35. PMID 22502620.
- Krisanaprakornkit, T; Krisanaprakornkit, W; Piyavhatkul, N; Laopaiboon, M (Jan 25, 2006). Krisanaprakornkit, Thawatchai, ed. "Meditation therapy for anxiety disorders". Cochrane Database of Systematic Reviews (1): CD004998. doi:10.1002/14651858.CD004998.pub2. PMID 16437509.
- Pittler MH, Ernst E (2003). Pittler, Max H, ed. "Kava extract for treating anxiety". Cochrane Database of Systematic Reviews (1): CD003383. doi:10.1002/14651858.CD003383. PMID 12535473.
- Witte S, Loew D, Gaus W (March 2005). "Meta-analysis of the efficacy of the acetonic kava-kava extract WS1490 in patients with non-psychotic anxiety disorders". Phytother Res 19 (3): 183–188. doi:10.1002/ptr.1609. PMID 15934028.
- Saeed SA, Bloch RM, Antonacci DJ (August 2007). "Herbal and dietary supplements for treatment of anxiety disorders". Am Fam Physician 76 (4): 549–556. PMID 17853630.
- Saeed, SA; Bloch, RM; Antonacci, DJ (Aug 15, 2007). "Herbal and dietary supplements for treatment of anxiety disorders". American family physician 76 (4): 549–56. PMID 17853630.
- Kozlowska K., Hanney L. (1999). "Family assessment and intervention using an interactive are exercise". Australia and New Zealand Journal of Family Therapy 20 (2): 61–69. doi:10.1002/j.1467-8438.1999.tb00358.x.
- Bratton, S.C., & Ray, D. (2002). Humanistic play therapy. In D.J. Cain (Ed.), Humanistic psychotherapies: Handbook of research and practice (pp. 369-402). Washington, DC: American Psychological Association.
- Stanford University School of Medicine, Department of Psychiatry and Behavioral Sciences. "Principles and Practice of Geriatric Psychology, Second Edition". Pamela J. Swales, Erin L. Cassidy. Javaid I. Sheikh. Retrieved 13 February 2012.
- Ballenger, JC; Davidson, JR; Lecrubier, Y; Nutt, DJ; Borkovec, TD; Rickels, K; Stein, DJ; Wittchen, HU (2001). "Consensus statement on generalized anxiety disorder from the International Consensus Group on Depression and Anxiety". The Journal of clinical psychiatry. 62 Suppl 11: 53–58. PMID 11414552.
- Vos, T; Flaxman, AD; Naghavi, M; Lozano, R; Michaud, C; Ezzati, M; Shibuya, K; Salomon, JA; Abdalla, S et al (Dec 15, 2012). "Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010". Lancet 380 (9859): 2163–96. doi:10.1016/S0140-6736(12)61729-2. PMID 23245607.
- al.], edited by Helen Blair Simpson ... [et (2010). Anxiety disorders : theory, research, and clinical perspectives (1. publ. ed.). Cambridge, UK: Cambridge University Press. p. 7. ISBN 978-0-521-51557-3.
- Kessler RC, Berglund P, Demler O, Jin R, Merikangas KR, Walters EE (June 2005). "Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication". Arch. Gen. Psychiatry 62 (6): 593–602. doi:10.1001/archpsyc.62.6.593. PMID 15939837.
- Brockveld, Kelia C.; Perini, Sarah J.; Rapee, Ronald M. (2014). "6". In Hofmann, Stefan G.; DiBartolo, Patricia M. Social Anxiety: Clinical, Developmental, and Social Perspectives (3 ed.). Elsevier. ISBN 978-0-12-394427-6.
- Hofmann, Stefan G.; Asnaani, Anu (December 2010). "Cultural Aspects in Social Anxiety and Social Anxiety Disorder". Depress Anxiety 27 (12). doi:10.1002/da.20759. Retrieved December 7, 2014.
- Fricchione, Gregory (12 August 2004). "Generalized Anxiety Disorder". New England Journal of Medicine 351 (7): 675–682. doi:10.1056/NEJMcp022342.
- Khouzam, HR (March 2009). "Anxiety Disorders: Guidelines for Effective Primary Care. Part 1: Diagnosis". Consultant 49 (3).
- Khouzam, HR (April 2009). "Anxiety Disorders: Guidelines for Effective Primary Care. Part 2: Treatment". Consultant 49 (4).
- Vanin, John; Helsley, James (2007). Anxiety Disorders: A Pocket Guide For Primary Care. Humana Press. ISBN 978-1-58829-923-9.
- Craske, Michelle Genevieve (2003). Origins of Phobias and Anxiety Disorders: Why More Women than Men?. Amsterdam: Elsevier. ISBN 0-08-044032-0.
- Schutz, Samantha (2006). I Don't Want to Be Crazy: A Memoir of Anxiety Disorder. www.samanthaschutz.net (PUSH). ISBN 978-0-439-80518-6.