Generalized anxiety disorder

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Irfan Dotani

Generalized anxiety disorder was first recognized as a symptom by Sigmund Freud. In 1980, ‘The American Psychiatric Association’ introduced GAD as a diagnosis in the DSM-III.

• In the late 19th century, Sigmund Freud recognized anxiety as:^[1]
  • A “signal of danger”
  • A cause of “defensive behavior“
• He believed we acquire anxious feelings through classical conditioning and traumatic experiences.

• In the 19th century into the 20th century, the terms used to diagnose generalized anxiety included:^[2]
  • “Pantophobia”
  • “Anxiety neurosis”
    • Such terms designated paroxysmal manifestations (panic attacks) as well as interparoxysmal phenomenology (the apprehensive mental state).
    • Generalized anxiety was considered one of the numerous symptoms of neurasthenia, a vaguely defined illness.

• In 1980, ‘The American Psychiatric Association’ introduced GAD as a diagnosis in the DSM-III.
  • Anxiety neurosis was split into:^[3]
    • GAD
    • Panic disorder
    • We maintain anxiety through operant conditioning;
      • When we see or encounter something associated with a previous traumatic experience, anxious feelings resurface.
    • We feel temporarily relieved when we avoid situations which make us anxious.
      • This only increases anxious feelings the next time we are in the same position, and we will want to escape the situation again and therefore will not make any progress against the anxiety.

• In 1980, DSM-III portrayed GAD as:^[4]
  • Generalized, persistent anxiety
• In 1987, DMS-III-R portrayed GAD as:
  • Unrealistic/excessive anxiety and worry (apprehensive expectation) about 2 or more life circumstances
• In 1992, ICD-10 portrayed GAD as:
  • Generalized and persistent anxiety, not restricted to or even predominating in any environmental circumstances (ie, “free-floating”)
• The ICD-11, beta draft, portrayed GAD as:
  • Marked symptoms of anxiety accompanied by either general apprehension (ie, “free-floating anxiety”) or worry focused on multiple everyday events (family, health, finances, school, or work)
• In 1994, DSM-IV portrayed GAD as:
  • Excessive anxiety and worry (apprehensive expectation) about a number of events or activities
  • Difficult to control the worry
• In 2013, DSM-V portrayed GAD as:
  • Excessive anxiety and worry (apprehensive expectation) about a number of events or activities
  • Difficult to control the worry

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Irfan Dotani

Generalized anxiety disorder falls under the category of anxiety disorder.

• Generalized anxiety disorder falls under the category of anxiety disorder.^[1]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Charmaine Patel, M.D. [2] Irfan Dotani

The differential diagnosis in generalized anxiety disorder is similar to that of panic disorder. It is important to rule out drug-induced conditions. The mental status examination should take in consideration the possibility of schizophrenia, obsessive-compulsive disorder, major depressive disorder, and both specific and social phobias.

• Adjustment disorder^[1]
• Anxiety disorder due to another medical condition^[1]

• Pheochromocytoma
• Hyperthyroidism

• Bipolar disorder^[1]
• Panic disorder– anxiety is only in regards to having a panic attack
• Post-traumatic stress disorder– presence of flashbacks, hyper-arousal, and hyper-vigilance
• Social phobia– anxiety only occurs in regards to social situations
• Obsessive-compulsive disorder– presence of obsessions and compulsions^[2]
• Separation anxiety disorder– anxiety occurs in response to being away from home or family
• Anorexia nervosa– anxiety occurs in response to potentially gaining weight
• Somatization disorder– multiple physical complaints
• Hypochondriasis– anxiety in regards to developing a specific disease
• Schizophrenia– presence of psychotic symptoms such as hallucinations and delusions
• Major depressive disorder– criteria requires two weeks of specific symptoms
• Medications– in particular stimulants such as methylphenidate, pseudoephedrine, and other decongestants or appetite suppressants
• Drug abuse– particularly stimulants and hallucinogenics such as cocaine, caffeine, amphetamines, and PCP^[3]
• Drug withdrawal– particularly alcohol withdrawal, benzodiazepine withdrawal, and opiate withdrawal.
• Hyperthyroidism– presence of an elevated TSH on laboratory findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Charmaine Patel, M.D. [2] Irfan Dotani

Generalized anxiety disorder is relatively common and has a lifetime prevalence of 900 per 100,000 (0.9%) in adolescents and 2,900 per 100,000 (2.9%) in adults.^[1] It is more common in women, and can develop in any age although it more commonly occurs in the third and fourth decade of life.

• The 12-months prevalence in overall population is:
  • 900 per 100,000 (0.9%) in adolescents
  • 2,900 per 100,000 (2.9%) in adults^[1]

• The World Health Organization‘s Global Burden of Disease project did not include generalized anxiety disorders.^[2] In lieu of global statistics, here are some prevalence rates from around the world:
  • Australia: 3 percent of adults^[2]
  • Canada: Between 3-5 percent of adults^[3]
  • Italy: 2.9 percent^[4]
  • Taiwan: 0.4 percent^[4]
  • United States: approx. 3.1 percent of people age 18 and over in a given year (6.8 million)

• The disorder most commonly has its onset in the third decade of life, and mostly occurs in persons under the age of 30 years old. Generalized anxiety disorder can be seen at any age.

• Generalized anxiety disorder is more commonly seen in females. This may partly be due to the increased tendency of women to report symptoms.

• Generalized anxiety disorder is more common in African Americans.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Irfan Dotani

Risk factors for developing generalized anxiety disorder include a positive family history, early adulthood, and a recent life stressor. Genetics along with substance-induced anxiety are large factors as well.

Risk factors for generalized anxiety disorder include:^[1]

• Behavioral inhibition
• Childhood adversities
• Genetic predisposition
• Harm avoidance
• Negative affectivity (neuroticism)
• Parental over-protection

• Genes are attributed to about 33% of general anxiety disorder’s variance.^[2]
• Individuals with a genetic predisposition for GAD are more likely to develop GAD.
  • Especially in response to a life stressor.^[3]

• Anxiety can be worsened through the use of benzodiazepines.^[4]
  • Benzodiazepines can lead to a lessening of anxiety symptoms.
• Similarly, long-term alcohol use is associated with anxiety disorders
  • Prolonged abstinence can result in a disappearance of anxiety symptoms.
• It can take up to two years for anxiety symptoms to return to baseline in about a quarter of people recovering from alcoholism.
• Tobacco smoking has been established as a risk factor for developing anxiety disorders.^[5]
• Excessive caffeine use has been linked to anxiety.

• In 1988–90, illness in approximately half of the patients attending mental health services at 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.^[6]
  • In these patients, anxiety symptoms, while worsening initially during the withdrawal phase, disappeared with abstinence from benzodiazepines or alcohol.
• Sometimes anxiety, pre-existed alcohol, or benzodiazepine dependence, keep anxiety disorders going and often progressively making them worse.
  • Recovery from benzodiazepines tends to take a lot longer than recovery from alcohol, but people can regain their previous good health.^[7]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Irfan Dotani

In the National Comorbidity Survey (2005), 58% of patients diagnosed with major depression were found to have an anxiety disorder. Accumulating evidence indicates that patients with comorbid depression and anxiety tend to have greater illness severity and a lower treatment response than those with either disorder alone. In addition, social function and quality of life are more greatly impaired. Approximately one-quarter of the patients with generalized anxiety disorder, will develop panic disorder.

• In the National Comorbidity Survey (2005), 58% of patients diagnosed with major depression were found to have an anxiety disorder; among these patients, the rate of comorbidity with GAD was 17.2%, and with panic disorder, 9.9%.
• Patients with a diagnosed anxiety disorder also had high rates of comorbid depression, including 22.4% of patients with social phobia, 9.4% with agoraphobia, and 2.3% with panic disorder.^[1]
  • For many, the symptoms of both depression and anxiety are not severe enough (i.e. are subsyndromal) to justify a primary diagnosis of either major depressive disorder (MDD) or an anxiety disorder.
• Patients can also be categorized as having mixed anxiety-depressive disorder, and they are at significantly increased risk of developing full-blown depression or anxiety. Appropriate treatment is necessary to alleviate symptoms and prevent the emergence of more serious disease.^[2]
• Accumulating evidence indicates that patients with comorbid depression and anxiety tend to have greater illness severity and a lower treatment response than those with either disorder alone. In addition, social function and quality of life are more greatly impaired.
  • In addition to coexisting with depression, research shows that GAD often coexists with substance abuse or other conditions associated with stress, such as irritable bowel syndrome.
• Patients with physical symptoms such as insomnia or headaches should also tell their doctors about their feelings of worry and tension.^[3]
  • This will help the patient’s health care provider to recognize whether the person is suffering from GAD.
• Approximately one-quarter of the patients with generalized anxiety disorder, will develop panic disorder.^[4]