Two-year course of anxiety disorders: different across disorders or dimensions?

This study compares diagnostic and symptom course trajectories across different anxiety disorders, and examines the role of anxiety arousal vs. avoidance behaviour symptoms in course prediction.

Data were from 834 subjects with a current anxiety disorder from the Netherlands Study of Depression and Anxiety (NESDA) who were re-interviewed after 2 years. DSM-IV-based diagnostic interviews and Life Chart Interviews (LCI) were used to assess the diagnostic and symptom course trajectory over 2 years. Anxiety arousal and avoidance behaviour symptoms were measured with LCI, Beck Anxiety Inventory and Fear Questionnaire.

Prognosis varied across disorders, with favourable remittance rates of 72.5% for panic disorder without agoraphobia and 69.7% for generalized anxiety disorder; gradually declining to 53.5% for social phobia and 52.7% for panic disorder with agoraphobia. Only 42.9% of those with multiple anxiety disorder remitted, and this group showed a more chronic course than pure anxiety disorders. Both baseline duration and severity were course predictors. Avoidance behaviour symptoms predicted the outcome better than anxiety arousal symptoms.

These data suggest that the specific anxiety disorders such as recognized by DSM-IV are useful in predicting the outcome and that this may be determined largely by the relative severity of avoidance behaviour that patients have developed.