Risk of Hyperprolactinemia and Sexual Side Effects in Males 10-20 Years Old Diagnosed with Autism Spectrum Disorders or Disruptive Behavior Disorder and Treated with Risperidone

Objective: The aim of this study was to investigate the long-term treatment effects of risperidone on prolactin levels and prolactin-related side effects in pubertal boys with autism spectrum disorders (ASD) and disruptive behavior disorders (DBD). Method: Physical healthy 10-20-year-old males with ASD (n = 89) and/or DBD (n = 9) chronically treated (mean 52 months, range 16-126 months) with risperidone (group 1, n = 51) or not treated with any antipsychotic (group 2, n = 47) were recruited to this observational study from the child psychiatry outpatient clinic. Morning non-fasting serum prolactin levels were measured and prolactin-related side effects were assessed by means of questionnaires and physical examination. Group differences were tested with Student's t, chi(2), Fisher exact, and Mann-Whitney tests, and logistic regression analysis, according to the type and distribution of data. Results: Hyperprolactinemia was present in 47% of subjects in group 1 but only in 2% of subjects in group 2 (odds ratio 71.9; 95% CI, 7.7; 676.3). Forty-six percent of subjects in group1 had asymptomatic hyperprolactinemia. Current risperidone dose and 9-OH risperidone plasma level were significant predictors of hyperprolactinemia (p = 0.035 and p = 0.03, respectively). Gynecomastia and sexual dysfunction were present in 43% and 14% of the subjects in group1, respectively, compared with 21% and 0% of subjects in group 2 (p = 0.05 and p = 0.01). Gynecomastia was not significantly associated with hyperprolactinemia. Conclusions: Hyperprolactinemia is a common side effect in young males treated over the long term with risperidone. Young males treated with risperidone are more likely to report diminished sexual functioning than are those not treated with antipsychotics.