The Distribution of Body Mass Index Among Individuals With and Without Schizophrenia

Objective:The objective of this study was to estimate and compare the distributions of body mass index (BMI: kg/m2) among individuals with and without schizophrenia, and, thereby, place the weight gain-inducing effects of antipsychotic drugs into context.

Method:Data sources were (1) the mental health supplement of the 1989 National Health Interview Survey (NHIS; N = 80,130 nonschizophrenic and 150 self-reported schizophrenic individuals), (2) baseline BMI data from a drug trial of the antipsychotic ziprasidone supplied by Pfizer Inc (420 noninstitutionalized individuals with chronic psychotic disorders [DSM-IV schizophrenia or schizoaffective disorder]) and (3) data from the National Health and Nutrition Examination Survey III (NHANES III; N = 17,689 nonschizophrenic individuals) to act as a control group for the ziprasidone trial data.

Results:After age-adjusting BMI in each data set, the NHIS data revealed that men with schizophrenia have mean BMIs similar to those of men without schizophrenia (26.14 vs. 25.63, respectively). In contrast, women with schizophrenia in the NHIS data set had a significantly (p < .001) higher mean BMI than did women without schizophrenia (27.36 vs. 24.50, respectively). Moreover, each decile was higher for women with schizophrenia than for women without schizophrenia. Analysis of the ziprasidone and NHANES III data sets revealed that, on average, men with schizophrenia have mean BMIs comparable to those of men without schizophrenia (26.79 vs. 26.52, respectively). In these 2 data sets, women with schizophrenia also had a mean BMI similar to those of women without schizophrenia (27.29 vs. 27.39, respectively).

Conclusion:Although there may be a small subpopulation of schizophrenic individuals who are underweight, individuals with schizophrenia were, on the whole, as obese as or more obese than individuals without schizophrenia, suggesting that weight gain induced by antipsychotic agents is an important concern for many individuals.