Anxiety (generalized anxiety disorder)

BASIC INFORMATION
Anxiety may present as a symptom in a wide range of psychiatric and medical conditions. Generalized anxiety disorder (GAD) is a condition in which the individual experiences excessive anxiety, fear, and worry for most of the time, continuously for at least 6 months. The subjective anxiety must be accompanied by at least three somatic symptoms (e.g., restlessness, irritability, sleep disturbance, muscle tension, difficulty concentrating, or fatigability).
Anxiety is a subjective feeling of apprehension caused by a threat to a person or his values. Some describe it as an exaggerated feeling of impending doom, dread, or uneasiness. Unlike fear-a reaction to danger from a specific external source-anxiety is a reaction to an internal threat, such as an unacceptable impulse or a repressed thought that is straining to reach a conscious level or a real, threatened, or imagined threat to the patient's self-esteem.
Occasional anxiety is a rational response to a real threat and is a normal part of life. Overwhelming anxiety, however, can result in a generalized anxiety disorder (GAD)-uncontrollable, unrealistic worry that is persistent. More than 80% of patients with GAD suffer from major depression, arrhythmias, or social phobia. Onset is usually before age 20, and the patient usually has a history of childhood fears. It's equally common in men and women.
SYNONYMS
Anxiety neurosis
Chronic anxiety
EPIDEMIOLOGY & DEMOGRAPHICS
INCIDENCE (IN U.S.): 31% in 1 year.
PREVALENCE (IN U.S.):
• In general population: 4.1% to 6.6% lifetime
• In primary care setting: 2.9% (It is the most common anxiety disorder in this setting).
PREDOMINANT SEX: Females are more frequently affected (2:1 ratio), but they present for treatment less frequently (3:2 female:male).
PREDOMINANT AGE:
• 30% of patients report onset of symptoms before age 11 yr.
• 50% of patients have onset before age 18 yr.
PEAK INCIDENCE: Chronic condition with onset in early life
GENETICS: Concordance rates in dizygotic twins and monozygotic twins are not different (0% to 5%), but detailed analysis of 1033 female twin pairs finds that heredity contributes about 30% of the factors that may cause GAD.

Physical and psychological symptoms of anxiety

PHYSICAL FINDINGS & CLINICAL PRESENTATION
• Report of being “anxious” all of their lives
• Excessive worry, usually regarding family, finances, work, or health
• Sleep disturbance, particularly early insomnia
• Muscle tension (typically in the muscles of neck and shoulders)
• Headaches (muscle tension)
• Difficulty concentrating
• Day form of fatigue
• Gastrointestinal symptoms compatible with IBD (one third of patients)
• Physical consequences of anxiety are the driving force for patients seeking medical attention
• Comorbid psychiatric illness (e.g., dysthymia or major depression) and substance abuse (e.g., alcohol abuse) are frequent
ETIOLOGY
• There is no clear etiology.
• Several hypotheses centering on neurotransmitter (catecholamines, indolamines) and developmental psychology are used as framework for treatment recommendations.

DIAGNOSIS
DIFFERENTIAL DIAGNOSIS
• Wide range of psychiatric and medical conditions; however, for a diagnosis of GAD to be made a person must experience anxiety with coexisting physical symptoms the majority of the time continuously for at least 6 mo.
• Cardiovascular and pulmonary disease
• Hyperthyroidism
• Parkinson’s disease
• Myasthenia gravis
• Consequence of recreational drug use (e.g., cocaine, amphetamine, and PCP) or withdrawal (e.g., alcohol or benzodiazepines)
WORKUP
• History: required for diagnosis
• Physical examination: confirm the patient’s physical complaints
• Exclusion of organic basis for the complaints possibly requiring additional workup
TREATMENT
NONPHARMACOLOGIC THERAPY
• Cognitive-behavioral therapy
• Relaxation training
• Biofeedback
• Psychodynamic psychotherapy

Drug treatment and psychotherapy is most effective in treating a patient with this disorder. Complete symptomatic relief is rare, however. The benzodiazepine antianxiety drugs relieve anxiety but should only be prescribed for 4 to 6 weeks because the patient may develop tolerance to the drugs and because of a potential for abuse. Buspirone, an antianxiety drug, causes less sedation and less risk of physical and psychological dependence than the benzodiazepines. However, it takes several weeks to take effect.
Psychotherapy can help the patient identify and deal with the cause of anxiety, anticipate his reactions, and plan effective response strategies to deal with the anxiety. The patient may also learn relaxation techniques, such as deep breathing, progressive muscle relaxation, focused relaxation, and visualization.
ACUTE GENERAL Rx
• Acute treatment is rarely indicated because GAD is a chronic condition.
• Occasionally, patients are in acute distress, requiring physician to respond quickly; benzodiazepines are given under these conditions as drug of choice for both daytime anxiety and initial insomnia.
CHRONIC Rx
• Benzodiazepines provide long-term symptom control with only occasional problems with tolerance or abuse; however, rate of relapse after discontinuation of benzodiazepines may be twice the rate after discontinuation of the available nonbenzodiazepine anxiolytic buspirone.
• SSRIs and venlafaxine are also effective in generalized anxiety disorders.
• Buspirone is effective without any potential for tolerance or abuse.
• Tricyclic antidepressants are useful if an element of comorbid depression exists.
• Sedating antidepressants are also useful in ameliorating initial insomnia.
• Trazodone and nefazodone possibly have unique benefits for these patients.
DISPOSITION
• This condition is chronic with periodic exacerbations.
• Treatment is given to provide a significant degree of improvement, but symptoms and dysfunction may persist.
• The risk for suicide is higher than general population.