Onset of remission and relapse in depression: testing operational criteria through course description in a second Dublin cohort of first-admission participants.

BACKGROUND

This paper extends previous work describing course in depression using a recommended operational model that defines remission onset and relapse. We test whether a similar course pattern would emerge using this model in a new cohort of depressed participants.

METHODS

We recruited a cohort of 86 participants, first-time inpatients, with DSM-IV major depression. Outcome was assessed prospectively over a 13-month minimum follow-up period. Remission onset was defined as a Ham-D score <8 for two consecutive weeks; relapse as a Ham-D score >16 for two consecutive weeks and meeting DSM-IV criteria for major depressive disorder.

RESULTS

The cumulative probability of remission onset was 0.62 (SE=0.05) and 0.80 (SE=0.05) at 3 and 6 months following study entry. The relapse risk was 0.28 (SE=0.05) at 6 months post remission onset; 53% of those relapsing did so in the first 2 months post remission onset. Predictors of longer times to remission onset included: longer illness length, higher anxiety scores and unemployment; higher anxiety scores predicted relapse. The course pattern is similar to that reported previously.

LIMITATIONS

These findings apply to inpatients only. Course was not rated blind to all of the participants' baseline data.

CONCLUSIONS

Defining remission onset and relapse using this model is associated with a replicable course pattern. A singular clinical advantage of the model is the identification of those participants at highest risk of relapse 2 months post remission onset.