The epidemiology of pure and comorbid generalized anxiety disorder: a review and evaluation of recent research

Objective: Research documenting high rates of comorbidity among patients wi th generalized anxiety disorder (GAD) has led to the suggestion that GAD mi ght best be conceptualized as a prodrome, residual or severity marker of ot her disorders. Recent research investigating this suggestion is reviewed in this report. Method: A computer search cross-classified the terms 'Generalized Anxiety' and 'Comorbidity'. Results: Results arguing that GAD is an independent disorder include the fi nding that GAD is usually temporally primary in cases of comorbidity with m ajor depression, that primary GAD is a significant predictor of subsequent depression and that the course of GAD is independent of comorbidity. Studie s in both patient and community samples show that the impairment associated with pure GAD is equivalent to the impairment associated with pure depress ion. Conclusion: The results reviewed here support the view that GAD as an indep endent disorder is a major public health problem.