Comorbidity of depression and generalized anxiety: is there any distinct boundary?

Evidence for the absence of clear boundaries and divisions between depression and generalized anxiety is reviewed. Indeed, symptoms of depression and of generalized anxiety are strongly associated, with substantial overlap between them. Moreover, anxiety tends to precede depression, increasing the risk of onset of depression and influencing its subsequent course and outcome. Finally, depression and generalized anxiety seem to share the same genes and at least part of the environmental risk factors, and tend to respond to the same treatments. The nosological implications of these findings are discussed. (C) 1998 Rapid Science Publishers.