Objective: This study seeks to evaluate the weight gain effect within a community-based population of patients with diagnoses of depression, mood disorder, and schizophrenia receiving aripiprazole over a period of at least 6 months.
Method: The four million members of Kaiser Permanente of Southern California (KPSC) were queried for a four-year period between January 1, 2010 and December 31, 2013. The initial cohort comprised 25,682 KPSC members who received at least one dispense of aripiprazole. This initial cohort was split into those who received aripiprazole as a monotherapy ("Alone" group) and those who were given aripiprazole as part of a combination therapy. The group of patients that received aripiprazole and antidepressant with high serotonin reuptake inhibition we called "High" group while the group receiving aripiprazole and bupropion combination we called "Low" serotonin group. We compared the primary endpoint of mean percent weight change from baseline after 180 days of continuous treatment between the three groups. Three pairwise comparisons were made: High versus Alone, Low versus Alone, and Low versus High, using adjusted and unadjusted linear regression models.
Results: Within this population, patients on aripiprazole monotherapy showed statistically significant weight gain in all three groups. However, there was no statistically significant difference in weight gain between the aripiprazole monotherapy, the high serotonergic combination group, and the low serotonergic combination group. This finding applied even within the subset of patients who were considered obese (body mass index > 30).
Conclusions: The results suggest that weight gain is unchanged by combination treatments, but further research is required.
Keywords: Weight gain change; aripiprazole monotherapy; aripiprazole–antidepressant polypharmacy.