Early Improvements in Individual Symptoms to Predict Later Remission in Major Depressive Disorder Treated With Mirtazapine

Few studies, to our knowledge, have examined whether early improvements in individual, instead of overall, depressive symptoms predict remission in major depressive disorder (MDD). This post hoc analysis used data from 194 patients with MDD enrolled in a 6-week double-blind, placebo-controlled, randomized trial of mirtazapine, to identify improvements in specific individual depressive symptoms in the early phase that are associated with subsequent remission. Trajectories of individual depressive symptoms over 6 weeks were compared between remitters and nonremitters. Early improvement was defined as a ≥20% decrease in the Hamilton Rating Scale for Depression 17 items (HAM-D17) total score in weeks 1 and 2, and remission was defined as a HAM-D17 final score of ≤7. Reliability parameters were calculated for early improvements in predicting later remission. Whether improvement in each of the HAM-D17 symptoms in weeks 1 or 2 predicted remission was examined, using binary logistic regression analyses. As a result, improvements in weeks 1 and 2 were associated with sensitivity of 0.82 and 0.99 and specificity of 0.54 and 0.44, respectively, in predicting remission in week 6. Improvements in insomnia late (P =.04) and insight (P =.007) in week 1 and somatic symptoms general (P =.002) and insight (P =.04) in week 2 were associated with remission in week 6. In conclusion, early improvements in insight, insomnia late, and somatic symptoms general, as well as overall depressive symptoms, may serve as specific clinical indicators of subsequent remission in patients with MDD receiving mirtazapine.