Researchers have linked prolonged usage of Risperdal to an increase in prolactin levels in young boys. This elevated prolactin level is associated with Risperdal-induced gynecomastia. Studies have shown that 3 out of 10 adolescents might develop gynecomastia after taking Risperdal. Researchers have linked prolonged usage of Risperdal to an increase in prolactin levels in young boys. This elevated prolactin level is associated with Risperdal-induced gynecomastia. Studies have shown that 3 out of 10 adolescents might develop gynecomastia after taking Risperdal.