Comorbidity and the general neurotic syndrome.

The observation that people with an anxiety or depressive disorder also have an increased likelihood of having had other anxiety or depressive disorders in their lifetime means either that the separate causes of these disorders have aggregated, much more than chance would allow, or that some general vulnerability factor has made them liable to each and all of the disorders they report. In this paper, three separate sources of information-symptoms occurring in the general population, disorders occurring in the general population, and disorders occurring in patients who have sought treatment-are reviewed. In all three domains of information, a general vulnerability factor, associated with personality trait measures of high trait anxiety and poor coping, emerges as a principal cause of these symptoms or disorders, and accounts for the majority of the variation in the comorbidity of symptoms or disorders. This vulnerability factor is shown to be under substantial gentic control. Nevertheless it can be modified by appropriate treatment, and prevention strategies exist to reduce the incidence of the anxiety and depressive disorders.