Coryell W et al. – The severity of current anxiety symptoms within depressive episodes correlates strongly with the persistence of subsequent depressive symptoms and this relationship is stable over decades.

• Participants with unipolar (n = 476) or bipolar (n = 335) depressive disorders were intensively followed for a mean of 16.7 years (s.d. = 8.5).

• The number and severity of anxiety symptoms, but not the presence of pre-existing anxiety disorders, showed a robust and continuous relationship to the subsequent time spent in depressive episodes in both unipolar and bipolar depressive disorder.
• The strength of this relationship changed little over five successive 5-year periods.