Can People With Nonsevere Major Depression Benefit From Antidepressant Medication?

Abstract

Several meta- or mega-analyses suggest antidepressant medications should be given only to severely depressed patients. In our experience, mild depression benefits from medication. We reanalyzed 1 clinic's randomized placebo-controlled antidepressant studies, limiting analyses to patients with major depressive disorder (MDD) without severe illness, to determine whether nonsevere depression responds to antidepressant medication. Archives of the Depression Evaluation Service outpatient clinic of the New York State Psychiatric Institute were searched for randomized, placebo-controlled antidepressant studies that were conducted between 1977 and 2009 and included patients having MDD and pretreatment Hamilton Depression Rating Scale (HDRS) scores < 23. Six placebo-controlled studies were found, including 8 active treatment arms and 1,440 patients. 825 patients were randomized and had MDD and an HDRS score < 23. DSM-III, DSM-III-R, or DSM-IV diagnostic criteria contemporary to each study were employed. Treatments were compared within study and via a patient-level meta-analysis using analysis of covariance (ANCOVA) of HDRS end point scores adjusted for pretreatment score. The number needed to treat (NNT) was calculated from remission rates (HDRS end point score ≤ 7), which were compared by χ². Effect sizes were calculated from change in HDRS scores. Secondary analyses investigated the effect of chronicity and atypical features on treatment response. Three of 6 studies showed significant (P < .001) treatment effects by ANCOVA, and 4 of 6 studies showed significant (P < .04) differences in remission. The NNT ranged from 3 to 8. Effect sizes ranged from -0.04 to 0.8, with 4 of 8 greater than 0.4. The patient-level meta-analysis confirmed these results; neither chronicity nor atypical features significantly affected outcome. Secondary analyses utilizing global ratings and self-report mimicked the main findings. Several studies demonstrated significant antidepressant efficacy for patients having nonsevere MDD. Efficacy was not trivial, as NNT ranged from 3 to 8, a range accepted by researchers as sufficiently robust to recommend treatment. These findings suggest mild-moderate MDD can benefit from antidepressants, contrary to findings by several other meta- or mega-analyses.