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

Demographics

• 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

Diagnosis

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

Treatment

Medications

• 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 ...