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For further information, see CMDT Part 25-05: Anxiety Disorders

Key Features

Essentials of Diagnosis

  • Persistent excessive anxiety or chronic fear and associated behavioral disturbances

  • Somatic symptoms referable to the autonomic nervous system or to a specific organ system (eg, dyspnea, palpitations, paresthesias)

  • Not limited to an adjustment disorder

  • Not a result of physical disorders (eg, hyperthyroidism), other psychiatric conditions (eg, schizophrenia), or drug abuse

General Considerations

  • Anxiety disorders include

    • Generalized anxiety disorder (GAD)

    • Panic disorder

    • Phobic disorder

  • GAD

    • Everyday activities trigger symptoms

    • Symptoms present on most days for at least 6 months

  • Panic disorder

    • Symptoms occur in recurrent episodes with unpredictable triggers

    • Somatic symptoms are often marked

  • Phobic disorder

    • Symptoms occur predictably

    • Follows exposure to certain objects or situations


  • About 7% of women and 4% of men will meet criteria for GAD over a lifetime

  • Prevalence of panic disorder: 3–5%, 25% with coincident obsessive-compulsive disorder

Clinical Findings

Symptoms and Signs

  • Anxiety or fear

  • Apprehension or worry

  • Difficulty concentrating

  • Insomnia and fatigue

  • Irritability

  • Feelings of impending doom

  • Recurrent thoughts or fears

  • Repetitive actions and rituals

  • Avoidant behaviors

  • Sympathomimetic symptoms

    • Tachycardia

    • Hyperventilation

    • Tremor

    • Sweating

  • Somatic symptoms

    • Paresthesias

    • Dizziness

    • Nausea

    • Chest pain

    • Palpitations

Differential Diagnosis

  • Hyperthyroidism

  • Pheochromocytoma

  • Sympathomimetic drug use

  • Myocardial infarction

  • Hypoglycemia

  • Adjustment disorder


Laboratory Tests

  • Serum thyroid-stimulating hormone

  • Complete blood count

  • Toxicology screen (if drug abuse is suspected)

  • Blood glucose

Imaging Studies

  • Chest radiograph may be indicated

  • Head CT may be useful in dissociative symptoms to rule out temporal lobe lesion

Diagnostic Procedures

  • ECG

  • Electroencephalogram may be useful in dissociative symptoms to rule out temporal lobe lesion



  • See Table 25–1

  • GAD

    • Antidepressants (including the selective serotonin reuptake inhibitors [SSRIs] and serotonin norepinephrine reuptake inhibitors [SNRIs]) are safe and effective; they appear to be as effective as the benzodiazepines without the risks of tolerance or dependence

    • SSRIs, such as escitalopram and paroxetine, are FDA-approved

    • SNRIs

      • Venlafaxine (start 37.5–75.0 mg once daily orally)

      • Duloxetine (start 30 mg once daily orally)

    • Buspirone

      • Sometimes used as an augmenting agent in the treatment of depression and compulsive behaviors

      • Also effective for generalized anxiety

      • Usually given in a total dose of 30–60 mg/day in divided doses

      • Higher doses are sometimes associated with side effects of gastrointestinal symptoms and dizziness

    • Gabapentin (titrated to doses of 900–1800 mg orally daily, with larger doses at night) and pregabalin

      • Appear effective

      • Lack the habit-forming potential of the benzodiazepines

  • Panic disorder

    • SSRIs

      • Fluoxetine

      • Paroxetine

      • Sertraline

    • SNRI

      • Venlafaxine

    • Benzodiazepines

      • Clonazepam and alprazolam

      • Use early ...

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