Predictors of 1-year outcome in depression

Objective: We compared several different methods for assessing depression 'recovery' over a 1-year review interval, to determine the utility of the contrasting approaches. Second, we assessed baseline predictors of 1-year outcome and recovery status. Third, we examined the extent to which predictors showed consistency across the variable definitions of outcome and recovery. Methods: Twelve-month outcome was assessed in a sample of 182 subjects who at baseline assessment met DSM criteria for a major depressive episode. The contrasting methods involved a defined percentage reduction in Beck Depression Inventory self-rating scores, formalised change point definitions, no longer meeting DSM-IV major depression criteria, and clinical global improvement (CGI) ratings. Results: Sixty-one per cent reached formalised change point criteria for full remission or recovery when trajectories across the 12-month interval were examined. Other measures quantified recovery rates ranging from 43% to 70%. Those with a psychotic or melancholic depression were more likely to have achieved recovery status in some analyses. Non-recovery at 12 months was predicted most consistently by higher baseline levels of anxiety and depression; high trait anxiety and a lifetime anxiety disorder; disordered personality function; and having reported exposure to acute and enduring stressors at baseline assessment. Conclusions: While the CGI was the superior system in terms of number of significant discriminating predictors of outcome, the change point definitional approach provides much greater information across the follow-up interval, arguing for their complementary utility. As several currently identified baseline predictors of outcome (i.e. anxiety, disordered personality function) also predicted onset of depression, their relevance as both depression-inducing and depression-propagating variables is suggested.