Generalized anxiety disorder

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Overview
Generalized anxiety disorder (GAD) is an anxiety disorder that is characterized by excessive, uncontrollable and often irrational worry about everyday things, which is disproportionate to the actual source of worry. This excessive worry often interferes with daily functioning, as individuals suffering GAD typically catastrophise, anticipate disaster, and are overly concerned about everyday matters such as health issues, money, family problems, or work difficulties. They often exhibit a variety of physical symptoms, including fatigue, headaches, muscle tension, muscle aches, difficulty swallowing, trembling, twitching, irritability, sweating, and hot flashes. These symptoms must be consistent and on-going, persisting at least 6 months, for a formal diagnosis of GAD to be introduced. Approximately 6.8 million American adults experience GAD, affecting about twice as many women as men.

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

Potential Causes of GAD
Some research suggests that GAD may run in families, and it may also grow worse during stress. GAD usually begins at an earlier age and symptoms may manifest themselves more slowly than in most other anxiety disorders. Some people with GAD report onset in early adulthood, usually in response to a life stressor. Once GAD develops, it is chronic.

Diagnosis
According to the Diagnostic and Statistical Manual IV-Text Revision (DSM-IV-TR), the following criteria must be met for a person to be diagnosed with Generalised Anxiety Disorder.
 * 1) Excessive anxiety and worry (apprehensive expectation), occurring more days than not for at least six months, about a number of events or activities (such as work or school performance).
 * 2) The person finds it difficult to control the worry.
 * 3) The anxiety and worry are associated with three (or more) of the following six symptoms (with at least some symptoms present for more days than not for the past 6 months). Note: Only one item is required in children.
 * 4) restlessness or feeling keyed up or on edge
 * 5) being easily fatigued
 * 6) irritability
 * 7) muscle tension
 * 8) difficulty falling or staying asleep, or restless unsatisfying sleep
 * 9) difficulty concentrating or the mind going blank
 * 10) The focus of the anxiety and worry is not confined to features of an Axis I disorder, e.g., the anxiety or worry is not about having a panic attack (as in panic disorder), being embarrassed in public (as in social phobia), being contaminated (as in obsessive-compulsive disorder), being away from home or close relatives (as in Separation Anxiety Disorder), gaining weight (as in anorexia nervosa), having multiple physical complaints (as in somatization disorder), or having a serious illness (as in hypochondriasis), and the anxiety and worry do not occur exclusively during post-traumatic stress disorder.
 * 11) The anxiety, worry, or physical symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
 * 12) The disturbance is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition (e.g., hyperthyroidism) and does not occur exclusively during a Mood Disorder, a Psychotic Disorder, or a Pervasive Developmental Disorder.

SSRIs
Pharmaceutical treatments for GAD, include selective serotonin reuptake inhibitors (SSRIs), which are antidepressants that influence brain chemistry to block the reabsorption of serotonin in the brain. SSRIs are mainly indicated for clinical depression, but are also effective in treating anxiety disorders. Common side effects include nausea, sexual dysfunction, headache, diarrhea, among others. Common SSRIs prescribed for GAD include:


 * fluoxetine (Prozac)
 * paroxetine (Paxil)
 * escitalopram (Lexapro;Cipralex)

Other Drugs

 * imipramine (Tofranil)
 * venlafaxine (Effexor)
 * Buspirone (BuSpar)

Venlafaxine (Effexor) is a serotonin-norepinephrine reuptake inhibitor (SNRI). SNRIs, a class of drugs related to the SSRIs, alter the chemistries of both norepinephrine and serotonin in the brain. Imipramine (Tofranil) is a tricyclic antidepressant (TCA). TCAs are thought to act on serotonin, norepinephrine, and dopamine in the brain. Buspirone is a serotonin receptor agonist belonging to the azaspirodecanedione class of compounds.

Benzodiazepines
Benzodiazepines (or "benzos") are fast-acting sedatives that are also used to treat GAD and other anxiety disorders. These are often given in the short-term due to their nature to become habit-forming. Side effects include drowsiness, reduced motor coordination and problems with equilibrioception. Common benzodiazepines used to treat GAD include :


 * alprazolam (Xanax)
 * chlordiazepoxide (Librium)
 * clonazepam (Klonopin)
 * diazepam (Valium)
 * lorazepam (Ativan)

Herbal
Kava, a relaxant made from a root only of a relative of the black pepper plant, is effective at controlling anxiety - particularly when used as a short term fast acting drug in combination with CBT (see below). The recommended use is for a support person such as the GAD sufferer's partner or housemate to encourage a dose when anxiety strikes as the patient is often unwilling/unable to dose themselves. Kava is absorbed through most mucous membranes and takes effect in roughly the same time as alcohol. It is a symptomatic relief for anxiety and does not address the fundamental problem, but it does give the patient a reliable mental crutch to work through the core problems. It appears that the required dosage actually decreases with regular use, perhaps as a form of conditioning. Two major advantages of Kava supported therapy are the rapid response of the active ingredients (removing the need for titration) and the lack of withdrawal symptoms. There are no specific contraindications with other chemical treatments, but caution must be observed when the patient is already taking psychoactive drugs.

Cognitive behavioral therapy
A psychological method of treatment for GAD is cognitive behavioral therapy (CBT), which involves a therapist working with the patient to understand how thoughts and feelings influence behavior. The goal of the therapy is to change negative thought patterns that lead to the patient's anxiety, replacing them with positive, more realistic ones. Elements of the therapy include exposure strategies to allow the patient to gradually confront their anxieties and feel more comfortable in anxiety-provoking situations, as well as to practice the skills they have learned. CBT can be used alone or in conjunction with medication.

GAD and Comorbid Depression
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. 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.

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. This will help the patient's health care provider to recognize whether the person is suffering from GAD.