Panic disorder. An overlapping or independent entity?

We compared three groups of patients with panic disorder, generalised anxiety disorder and major depressive episode with a control group. Methods of comparison included a clinical profile of the patients, assessed by the Arabic version of the Present State Examination (PSE), a psychological battery of tests measuring personality traits and depressive and anxiety states, and the dexamethasone suppression test (DST) as a biological marker. Our data showed that psychological assessment and DST did not significantly differentiate between the three disorders. Despite a symptom overlap between the disorders, however, some symptoms were associated significantly more often with one disorder than another. Patients with panic disorder differed from patients with major depressive episode in showing more situational, avoidance and free floating anxiety, and more anxious foreboding. They showed less self-negligence, ideas of guilt, early awakening and social withdrawal. Compared with patients with generalised anxiety disorder, patients with panic disorder showed more loss of interest and muscle tension and less anxious foreboding, restlessness, inefficient thinking, social withdrawal and delayed sleep. Our conclusion is that the clinical course and the symptom profile of panic disorder justifies its existence as an independent diagnostic category.