Obesity as a risk factor for antipsychotic noncompliance

Weight gain is a common side effect of antipsychotic medications and is of particular concern with most of the newer "atypical" antipsychotics. It is, therefore, increasingly important to understand the impact of obesity and perceived weight problems on compliance with these medications.

A survey of treatment and health issues was mailed to local chapters of the National Alliance for the Mentally Ill (NAMI) and National Mental Health Association (NMHA), who distributed them to people with schizophrenia. Noncompliance was defined as a self-report of missing any antipsychotic medication in the previous month. The primary independent variables were (1) body mass index (BMI; weight [kg]/height [m2])-categorized as normal (< 25, n = 73), overweight (25-30, n = 104), or obese (> 30, n = 100)-and (2) subjective distress over weight gain. Other independent variables included demographics, medication attitudes, and treatment satisfaction.

BMI status and subjective distress from weight gain were predictors of noncompliance. Obese individuals were more than twice as likely as those with a normal BMI to report missing their medication (OR = 2.5; CI 1.1-5.5). A comprehensive model suggested that the primary mediator of noncompliance was distress over weight gain.

There appears to be a significant, positive association between obesity and subjective distress from weight gain and medication noncompliance, even when accounting for other possible confounding factors.