Do SSRI Antidepressants Increase The Risk of Extrapyramidal Side Effects In Patients Taking Antipsychotics?

PURPOSE Among antidepressants, selective serotonin reup-take inhibitors (SSRIs) have enjoyed great popularity among clinicians as well as generally wide acceptance and tolerance among patients. A potentially overlooked side effect of SSRIs is the occasional occurrence of extrapyramidal symptoms (EPS), which could be a concern when SSRIs are used with antipsychotics. This study was designed to explore the possible association between SSRI antidepressant use and the incidence of EPS side effects in patients who take concomitant antipsychotic medications. METHODS The University of Michigan conducted a study at the four Michigan state mental health hospitals between May 2010 and October 2010. The Michigan Public Health Institute collected data using the InterRAI Mental Health Assessment (InterRAI MH). The present study is a retrospective cohort analysis of the cross-sectional data that were collected. Within these institutions, 693 residents were using antipsychotics. We measured the observed frequency of seven EPS recorded in the InterRAI MH within three groups of patients: 1) those on antipsychotic drugs who were taking an SSRI antidepressant; 2) those on antipsychotic drugs who were not taking an antidepressant; and 3) those on antipsychotic drugs who were taking a non-SSRI antidepressant. Differences in the prevalence of EPS were tested using one-way analysis of variance. RESULTS There were no significant differences in the observed EPS frequencies among the three groups (F 2,18 = 0.01; P < 0.9901). CONCLUSION In this study, SSRIs did not appear to potentiate the occurrence of EPS in patients using antipsychotics.