In patients with remitting depression, higher suicidal ideation during the current depressive episode, residual symptoms at remission, and greater severity of side effects at remission may be predictors of subsequent relapse, according to a study published in the Journal of Affective Disorders.
The investigators of this study sought to explore predictors of depression relapse following remission using previous data from a multicenter randomized trial of patients with major depressive disorder.
The study cohort included 494 patients with remitting depression who scored <5 on the Patient Health Questionnaire (PHQ-9) after receiving antidepressant treatment for 9 weeks. Participants were divided into 2 groups: those who maintained remission status at week 25 and those who relapsed at week 25 with a PHQ-9 score ≥5. Patient demographics and clinical characteristics reported at baseline (including onset age of first depressive episode, number of previous episodes, length of current episode) along with PHQ-9 scores at week 0 were examined as potential predictors of depression relapse at week 25. Frequency, Intensity, and Burden of Side Effects Rating (FIBSER) Scale and PHQ-9 scores reported at week 9 were also explored as potential predictors of relapse.
Of the 494 participants achieving remission at week 9, 71 (14.4%; 95% CI, 12-18) experienced relapse at week 25 reporting mild depression (n=60, 12.1%), moderate depression (n=8, 1.6%), moderately severe depression (n=2, 0.4%), and severe depression (n=1, 0.2%). In logistic regression analysis, lower PHQ-9 depressive mood scores at week 0, higher PHQ-9 suicidal ideation scores at week 0, total PHQ-9 scores at week 9, and total FIBSER scores at week 9 were shown to significantly and independently predict depression relapse. However, when relapse was defined as a PHQ-9 score ≥10 at week 25 — instead of a PHQ-9 score ≥5 — no significant predictors were associated with relapse.
Limitations to the study included potential predictors that the study failed to identify, such as treatment resistance, and not accounting for the specific antidepressant regime, which may have affected the results. Transient relapse before week 25 was not measured, and an assessment period of 25 weeks may have been too short. The findings presented in this study may be sensitive to the specific definition of relapse.
Although 14.4% of participants with remitting depression at week 9 experienced depression relapse within 4 months, most relapses were mild. The development of suicidal ideation during the current depressive episode, along with residual symptoms and more severe side effects at remission may predict subsequent depression following remission.
Akechi T, Mantani A, Kurata K, et al. Predicting relapse in major depression after successful initial pharmacological treatment [published online March 5, 2019]. J Affect Disord. doi: 10.1016/j.jad.2019.03.004