Which depressive symptoms remain after response to cognitive therapy of depression and predict relapse and recurrence?

Background: Major Depressive Disorder (MDD) is highly prevalent, severely debilitating, and often recurrent. Greater residual depressive symptoms after acute phase treatment predict greater relapse and recurrence. It is unknown, however, which specific depressive symptoms remain and are most predictive.

Method: The current study examined (a) which specific residual symptoms remained after effective treatment with acute phase cognitive therapy (A-CT) for recurrent depression and (b) if any of those specific residual symptoms were risk factors for relapse and recurrence over a 2-year follow-up.

Results: After completing 20 sessions of A-CT, a substantial proportion of adult responders continued to endorse somatic anxiety (42%), psychological anxiety (37%), middle insomnia (36%), depressed mood (29%), loss of libido (29%), late insomnia (24%), anergia (21%), guilt feelings (18%), early insomnia (17%), and anhedonia (14%), as defined by the 17-item Hamilton Rating Scale for Depression (HRSD). Decreased agitation, increased psychological anxiety, increased loss of appetite, increased loss of libido, and increased hypochondriasis were all risk factors for relapse and recurrence over a 2-year follow-up (all p<.05), after stratifying on number of previous episodes and controlling for age at onset and whether A-CT responders received continuation phase CT instead of assessment only control.

Limitations: These findings are based on a limited sample size (n=84), which was modestly restricted in terms of gender, ethnicity, region, and mean education level.

Conclusions: These results confirm that residual symptoms are common after A-CT. We hypothesize that treatments, intervention modules, or durations that effect and/or target specific residual symptoms may further reduce depression relapse and recurrence.