Non-remission of depression in the general population as assessed by the HAMD-7 scale

Remission from the symptoms of depression is the optimal outcome for depression treatment. Many studies have assessed the frequency of treatment, but there are none that have estimated the frequency of treated remission in the general population. We addressed this issue in the population of Alberta using a brief Hamilton Depression Rating Scale (HAMD)-7 scale (recently validated against the HAMD-17 scale in a clinical setting) that has been proposed as a suitable indicator for remission in primary care. We used data from a survey conducted within the Alberta Depression Initiative in 2005 (n=3,345 adults), to produce a population-based estimate of the number of respondents taking antidepressant medication for depression. From this group we selected a subpopulation that did not screen positive when the MINI module for major depression was administered (i.e., who did not have an active episode). Non-remission in this subpopulation was assessed with a version of the HAMD-7 scale adapted for telephone administration by a nonclinician. Of the survey respondents, 189 reported taking antidepressant medication for depression. Of these, 115 were found not to have an active episode. However, 49.0% of this subpopulation was not in remission as evaluated by the HAMD-7. We estimate that 1.3% (95% confidence interval, 0.9-2.0%) of the population is in treated non-remission for depression. Our study indicates a substantial degree of non-remission from depression in individuals taking antidepressants in the general population. This suggests that, in addition to increasing the frequency of treatment, increasing the effectiveness of treatment can have an impact on population health.