PREDICTING RELAPSE FROM THE TIME TO REMISSION DURING THE ACUTE TREATMENT OF DEPRESSION: A RE-ANALYSIS OF THE STAR*D DATA

Abstract Background Major depressive disorder (MDD) is a recurrent illness. However, there is still lack of clinical data to predict relapse at an early point in patients with depression. Aims and Objectives The objective of this analysis was to investigate the association between the time taken to achieve remission in the acute phase, and the subsequent relapse rate or time to relapse using the Sequenced Treatment Alternatives to Relieve Depression dataset. Method Data of 1,296 outpatients with nonpsychotic depression who entered a 12-month naturalistic follow-up period after achieving remission with citalopram for up to 14 weeks were analyzed. One-way analysis of variance and the Jonckheere-Terpstra trend test were performed to compare the relapse rates and days to relapse during the follow-up period among those who achieved remission at weeks 2, 4, 6, 9, 12, and 14. Remission and relapse were defined as scores of <=5 and >=11, respectively, on the 16- Item Quick Inventory of Depressive Symptomatology and Self-Report. Multivariate logistic regression analysis was also performed in order to examine other demographic and clinical characteristics which are associated with subsequent relapse. Results A total of 1,093 participants achieved remission during Step 1 treatment and received at least one assessment during the follow-up period. The mean± SD weeks taken to achieve remission were 6.4±3.8. Among them, 362 (33.1%) patients relapsed during the follow-up period. The mean± SD days to subsequent relapse after remission were 160.0±99.8. The relapse rates were significantly different among those who achieved remission each week (F(5, 1087)=4.995, p <0.001). The lowest and highest relapse rates were observed in those who achieved remission at weeks 4 (25.7%) and 12 (42.4%), respectively, with a significant difference (p =0.006). There was also a significant negative trend between the weeks taken to achieve remission and the days to relapse (z=-6.13, p <0.001). In the multivariate logistic regression analysis, weeks at achieving remission status were associated subsequent relapse in the follow-up phase (OR=1.05±0.03, p=0.02). Older age, longer current episodes and baseline severity of depression were also significantly associated with subsequent relapses during the follow-up period. Discussion & Conclusions The present findings demonstrated that achieving remission at earlier weeks during treatment was associated with a lower relapse rate and a longer time to relapse during the one- year follow-up period. These results indicate that patients with depression who show a faster response to antidepressant treatment are more likely to maintain remission in the long term. Thus, to prevent relapse, it is critical to closely monitor patients who take a longer time to achieve remission.