فعال سازی سمپاتیکی در اختلال اضطراب فراگیر گسترده تعریف شده

The definition of generalized anxiety disorder (GAD) has been narrowed in successive editions of DSM by emphasizing intrusive worry and deemphasizing somatic symptoms of hyperarousal. We tried to determine the clinical characteristics of more broadly defined chronically anxious patients, and whether they would show physiological signs of sympathetic activation. A group whose chief complaint was frequent, unpleasant tension over at least the last six weeks for which they desired treatment, was compared with a group who described themselves as calm. Participants were assessed with structured interviews and questionnaires. Finger skin conductance, motor activity, and ambient temperature were measured for 24 h. Results show that during waking and in bed at night, runs of continuous minute-by-minute skin conductance level (SCL) declines were skewed towards being shorter in the tense group than in the calm group. In addition, during waking, distributions of minute SCLs were skewed towards higher levels in the tense group, although overall mean SCL did not differ. Thus, the tense group showed a failure to periodically reduce sympathetic tone, presumably a corollary of failure to relax. We conclude that broader GAD criteria include a substantial number of chronically anxious and hyperaroused patients who do not fall within standard criteria. Such patients deserve attention by clinicians and researchers.

Whether psychiatric diagnostic categories are distinct biological entities or the artificial product of classificatory logic has long been a matter of debate. The absence of firm biological foundations for most psychiatric diagnoses has weakened arguments for biological categories and encouraged logical ones. From a logical point of view, anxiety disorders should be assigned to categories on the basis of the presence or absence of sets of features. To qualify for a disorder, the anxiety should be excessive, more than the anxiety of the average person under similar circumstances and severe enough to impair functioning. Essential for categorization as an anxiety disorder is that anxiety be a primary aspect of the diagnosis and not secondary to other diagnoses such as psychosis or depression. After that, further classification is attempted on the basis of further qualitative or quantitative descriptors of the anxiety. Features usually considered are whether the anxiety is acute or chronic, whether it is in response to identifiable external stimuli, whether there was a history of traumatic events, and what behavior or thinking accompanies the anxiety. Based on these considerations, diagnostic systems have usually identified a category of chronic anxiety where external stimuli, traumatic events, and psychotic thought processes have not played a major role. In the current diagnostic system, this category is Generalized Anxiety Disorder (GAD), the evolution of which through DSM editions is instructive of classificatory logic. Patients diagnosed with DSM-III GAD were often given other diagnoses by clinicians ostensibly following the same diagnostic definitions, which challenged the distinctness and thereby the legitimacy of this category. To improve separation from other mood and anxiety disorders, DSM-III-R made worry that included topics different from those typical of other anxiety disorders, a required symptom (reviewed by Barlow et al., 1986). Extending the requirement in DSM-IV to be that the worry had to be difficult to control, further improved this separation. At the same time, many of the symptoms of autonomic hyperactivity were dropped because DSM-III-R defined GAD patients endorsed these symptoms infrequently and inconsistently (Marten et al., 1993).