Predictors of 1-year outcome in depression.

Abstract

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. 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. 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. 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.