Generalized anxiety disorder clinical presentation

The development of mild forms of anxiety and neuroveg-etative and/or cognitive responses to stress may represent an adaptive evolutionary step against environmentally (external) or self-triggered (internal) threats, but maladaptive reactions have also emerged in human evolution. Thus, anxiety disorders are maladaptive conditions in which disproportionate responses to stress, or even self-evoked responses, are displayed. Anxiety disorders are one of the most frequent psychiatric illnesses, and have a lifetime prevalence of 15- 20% [1, 89]. The most common presentations are generalized anxiety disorder, with a lifetime prevalence rate of close to 5% [1, 89] social anxiety disorder, with very variable lifetime prevalence rates ranging from 2 to 14% [90] panic disorder, with rates from 2 to 4% [1,89] and post-traumatic stress disorder (PTSD), with a prevalence rate close to 8%. Specific phobias, acute stress and obsessive-compulsive behavior are other clinical presentations of anxiety disorders. 

Humans were not untouched by this disaster. Visits to community clinics for primary care and mental health services in the affected area increased dramatically after the spill (Impact Assessments, 1990). Exposure to the incident was shown to have a profound impact on the prevalence of psychiatric disorders with increased rates of generalized anxiety disorder, posttraumatic stress disorder, and depressive symptoms present in the population (Palinkas, Petterson, Russell, Downs, 1993). 

The commonly used classes of antidepressants are discussed in the following sections, and information about doses and half-lives is summarized in Table 2-1. The antidepressant classes are based on similarity of receptor effects and side effects. All are effective against depression when administered in therapeutic doses. The choice of antidepressant medication is based on the patient s psychiatric symptoms, his or her history of treatment response, family members history of response, medication side-effect profiles, and comorbid disorders (Tables 2-2 and 2-3). In general, SSRIs and the other newer antidepressants are better tolerated and safer than TCAs and MAOIs, although many patients benefit from treatment with these older drugs. In the following sections, clinically relevant information is presented for the antidepressant medication classes individually, and the pharmacological treatment of depression is also discussed. The use of antidepressants to treat anxiety disorders is addressed in Chapter 3. 

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