The effect of previous mood states on switch rates: a naturalistic study

A recent study suggested that post-manic depressions (post-MD) may differ from post-euthymia depression (post-ED). The goal of this study was to compare the switch rates and length of depressive episodes stratified by the pre-depression mood states.

The course of 72 prospectively observed depressions in 28 patients with Bipolar I depressions were divided into post-MD versus ED. The two groups, both all episodes and first observed episode, only were compared in their switch rates and length of episode.

Almost two-thirds (65%) of episodes were rated as ED. There was no difference in switch rates between the two groups, whether analysed by all episodes, first episodes only, or episodes not treated with antidepressants. Length of depressive episodes were also not significantly different between the two groups.

These findings do not suggest different switch characteristics between post-MD and post-ED.