Converging lines of evidence from a variety of methods of inquiry support a developmental model for
panic disorder that includes a constitutional predisposition for anxiety influenced by genetic, familial, cognitive-behavioral and psychosocial factors, early expression during childhood, and variable manifestations during the life-cycle. Studies of patients followed up after acute
pharmacotherapy trials and those treated naturalistically are consistent with this model and portray
panic disorder as a generally
chronic condition with a longitudinal course marked by relatively brief intervals of remission and high rates of recurrence and relapse. Longitudinal and follow-up studies suggest that
panic attack frequency responds more readily and rapidly to
pharmacotherapy than do other aspects of
panic disorder such as
agoraphobia and generalized anxiety. In general, the presence of
agoraphobia is associated with more severe symptoms, greater chronicity, and more limited response to treatment. Other variables associated with chronicity and treatment resistance include patient-related factors (psychiatric and medical comorbidity, anxiety sensitivity) and pharmacologic factors (adequacy of dose, duration, and compliance). Although it is currently difficult to predict the
duration of treatment needed for an individual patient, available evidence suggests that a substantial proportion of patients may require chronic treatment for
panic disorder.