The effect of the time to remission on residual symptoms and functioning among depressive patients.

Objectives: To explore the effect of time to remission on residual symptoms, functioning and quality of life (QOL) of the patients with major depressive disorder (MDD).

Method: A total of 434 patients were enrolled from 16 sites of China. The Quick Inventory of Depressive Symptomatology-Self Report (QIDS-SR) and self-rating scales were assessed at baseline, and months 1, 3 and 6. Baseline remitters were defined as those subjects with a QIDS-SR score ≤ 5 at baseline. Later remitters was defined as those reaching remission one month (Month 1 remitters) or three month (Month 3 remitters) after baseline. Persistent non-remitters were defined as those with QIDS-SR score > 5 at all 3 assessments. A follow-up assessment was done at month 6 to examine outcomes. Cross-lagged models indicated QIDS-SR predicted social functioning and QOL.

Results: Totally, 179 patients at baseline achieved remission. An additional 141 participants remitted at month 1 (n = 94) or month 3 (n = 47), and 63 patients were persistent non-remitters. There were significant differences between all groups on depression severity at baseline. QOL was similar for both late remitter groups, which was better than non-remitters, but lower than early-remitters. Late remitters and non-remitters showed significant differences on change of functioning and QOL (P < 0.001) at each visit. By 6 months, all remitting groups showed lower depression severity and better social functioning and QOL than persistent non-remitters. Cross-lagged models indicated QIDS-SR predicted social functioning and QOL.

Conclusion: We confirmed the association of earlier remission with a better quality of remission at early stage; but the time to remission does not affect future functioning and QOL.