Lesion location and poststroke depression - Systematic review of the methodological limitations in the literature

Background-It has been hypothesized that poststroke depression (PSD) results from left hemisphere lesions. However, attempts to systematically review the data investigating lesion location and PSD have yielded conflicting results. We sought to investigate the methodological differences across the literature studying the relationship between lesion location and PSD. Summary of Review-A MEDLINE literature search to retrieve articles investigating the association between PSD and lesion location was performed. Information sought included source population of samples, definition of depression, standardized measurement of stroke and depression, blinding, time since stroke onset, and study design. Odds ratios (ORs) and 95% CIs were calculated with the use of Review Manager and MetaView statistical software. Twenty-six original articles were reviewed. Much of the heterogeneity across studies reflected differences in methodology. The direction of association between left hemisphere lesion location and PSD varied depending on whether patients were sampled as inpatients (OR, 1.36; 95% CI, 1.05 to 1.76) or from the community (OR, 0.60; 95% CI, 0.39 to 0.92). Change in the direction of association was also observed across assessment interval from the acute stroke (OR, 2.14; 95% CI, 1.50 to 3.04) to the chronic stroke (OR, 0.53; 95% CI, 0.30 to 0.93) phase. Differences in the measurement of depression, study design, and presentations of results also may have contributed to the heterogeneity of the findings. Conclusions-Several key initiatives should be addressed before future research is undertaken, including the development of a comprehensive measure of PSD, optimal poststroke assessment intervals, and determination of a representative population reference.