Is left stroke a risk-factor for selective serotonin reuptake inhibitor antidepressant treatment resistance?

The objective of the study was to detect changes of depression and cognitive level associated with right and left brain damage during SSRI treatment in subjects with post-stroke Major Depressive Disorder (MDD). After the baseline evaluation, the 45 patients included received a single oral dose of 20-40 mg of fluoxetine or 50-100 mg of sertraline. At day 0, 7, 14, 28, 42, and 56 a psychometric test battery comprising the Hamilton Depression Rating Scale (HDRS) and the Mini Mental State Examination (MMSE) was administered. In the whole group repeated measures ANOVAs revealed a highly significant (p < 0.0001) time effect for HDRS and MMSE scores. However, depression improved much more in right stroke subjects in comparison with left stroke subjects (p < 0.001 for the HDRS by laterality interaction). Moreover, there is a suggestion of a possible selective serotonin reuptake inhibitor (SSRI) efficacy in cognitive impairment associated to post-stroke MDD but in treatment-responders only. At the endpoint, chi-square analysis showed that there was a different prevalence rate of MDD between left (n = 10; 50 %) and right (n = 4; 16 %) stroke patients, whereas the prevalence rate of Minor Depression was identical (25 %). The SSRIs fluoxetine and sertraline could be efficacious treatments for post-stroke MDD but these findings suggest that left stroke could be a predictor of treatment resistance.