Sexual dysfunction associated with second-generation antipsychotics in outpatients with schizophrenia or schizoaffective disorder: An empirical evaluation of olanzapine, risperidone, and quetiapine

Objective: Evaluate sexual dysfunction, as measured by the Arizona Sexual Experience Scale (ASEX), in olanzapine-, quetiapine-, and risperidone-treated outpatients with schizophrenia or schizoaffective disorder. Method: The sexual functioning of 238 outpatients (age ≥ 18 years) with diagnoses of schizophrenia or schizoaffective disorder who took quetiapine (n = 57), olanzapine (n = 94), or risperidone (n = 87) was evaluated with a one-time rating of the ASEX. The dose range for each treatment group was 5 to 40 mg/day (M = 16.6 mg/day, SD = 7.4) for olanzapine; 1 to 8 mg/day (M = 3.9 mg/day, SD = 1.6) for risperidone; and 50 to 900 mg/day (M = 376.8 mg/day, SD = 213.4) for quetiapine. Antipsychotic group designation was based on medication treatment at study entry (i.e., non-random assignment). Participant characteristics were collected to test for treatment group differences and for potential associations with severity of sexual dysfunction. The primary data analysis was a mixed linear model analysis of covariance with age, gender, and presence/absence of antidepressant known to cause sexual dysfunction included as covariates. Results: There was a significant treatment effect on severity of sexual dysfunction, as measured by ASEX total scores (p = .04). The adjusted average ASEX total scores were lower in the quetiapine (M = 17.80) than in the risperidone (M = 19.69) or olanzapine (M = 20.34) groups. Individual comparisons of the treatments on adjusted average ASEX total scores indicated a significant difference between olanzapine and quetiapine (p = .04), but no difference between risperidone and quetiapine (p = .17) or olanzapine and risperidone (p = .76). Conclusions: Quetiapine was associated with less severe sexual dysfunction than olanzapine and risperidone (albeit the effect between risperidone and quetiapine was not statistically significant). Olanzapine and risperidone were associated with a comparable degree of sexual dysfunction. Patients in all three treatment groups, nonetheless, experienced a moderately high degree of sexual dysfunction. Because the patients were not randomized, conclusions must be interpreted within the context of the quasi-experimental design.