| Generalized anxiety disorder (GAD) is characterized by chronic, excessive, unrealistic worry accompanied by at least 3 of the following symptoms: feeling "wound up" or on edge, poor concentration, irritability, sleep disturbances, muscle tension and fatigue. Individuals with GAD may worry about many aspects of life, including competence at work or school, finances, relationships with family members and co-workers, or natural disasters. Worry may extend to personal safety, family members' health or life difficulties. The individual often experiences anxiety immediately upon awakening. Anxiety can be so severe that it impairs the person's ability to function in social relationships or at work. The DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision) notes that the strength, length, and frequency of anxiety are well out of proportion to actual situations or threats. The inability to control worrying is often accompanied by physical symptoms such as increased nervous system arousal (e.g., restlessness, sweating, palpitations, trembling, muscle tension, and dizziness) as well as cognitive symptoms (e.g., distractibility, inability to concentrate).
Genetic, biological, environmental and other factors contribute to the development of GAD. Anxiety may also be associated with sleep disorders, use of caffeine, over-the-counter medications, or herbal medications. Adrenergic drugs, cyclic antidepressants, amphetamines, cocaine, antihistamines, thyroid hormones, and antispasmodic drugs, can also play a role (O’Brien). Nutritional deficiencies, particularly deficiencies in certain B vitamins (e.g., niacin, thiamin and vitamin B12), can contribute to anxiety. With niacin deficiency, for example, symptoms progress from irritability, depression, and anxiety to more challenging psychiatric disturbances (O’Brien).
Recent research on anxiety disorders has shown a strong bidirectional relationship between anxiety disorders and underlying medical illness (e.g., asthma, irritable bowel syndrome, malignancies, cardiovascular disease, infectious diseases, and chronic pain). In the presence of comorbid illness, anxiety symptoms and functional impairment increase, symptoms of comorbid illness worsen and affect outcomes, and health-related quality of life is diminished (Roy-Byrne; O’Brien). Alcohol and drug abuse are often associated with anxiety disorders.Risk: GAD is seen approximately twice as often in females as in males. Most anxiety disorders begin in childhood or adolescence. Onset of anxiety in older adults is often related to an undiagnosed medical condition. Epidemiologic surveys show that GAD is more common among unmarried people, racial-ethnic minority members, and people of low socioeconomic status Anxiety as a trait has a familial association. First-degree biological relatives of patients with panic disorders have a 7-fold increased probability of developing panic disorder compared to the general population (Kessler). Risk is greater in individuals with certain chronic conditions such as thyroid disease, respiratory disease, gastrointestinal disease, migraine headaches, and allergies (Shearer). Incidence and Prevalence: Clinically significant anxiety is the most common mental health disorder, more prevalent than both affective and substance abuse disorders in the general population (Shearer). The highest prevalence of GAD occurs among middle-aged people. One-year prevalence for criterion-based anxiety disorders is 16% (ranging from 14% to 30% in primary care settings) and lifetime prevalence is 28.8%; lifetime prevalence is 22.7% for isolated panic attacks (Shearer). |