AISD (Antipsychotic induced sexual dysfunction) is one of the most important reasons for therapeutic noncompliance. AISD is often described as adverse events of hyperprolactinemia, induced due to immoderate D2 occupancy (more than 72%) in the tuberoinfundibular system. Consequently the sex steroids decrease. Regulation of Follitropin secretion involves a complex balance between stimulation by GnRH from the hypothalamus, inhibitory feedback by sex steroids, Inhibins A (in both sexes) and B (in male) from the gonads and autocrine/paracrine modulation by Activin and Follistatin within the pituitary.

We have tried to verify the hypothesis that inhibins could be a better marker of sexual dysfunction than prolactinemia in patients (16 men and 11 women) with stable therapy and psychopathology with a diagnosis of schizophrenia, age 18-40 years. Follitropin, Lutropin, Prolactin, TSH, Estradiol, Progesterone, Testosterone, Inhibin A (in women) and B, Activin and Follistatin were used to measure the endocrinological condition. Structured Adverse Effects Rating Scale, UKU (hyperprolactinemia), Arizona Sexual Experience Scale and International Index of Erectile dysfunction in men were used to detect sexual dysfunction.

Inhibin B in men, not in women, correlated with sexual dysfunction (p < 0.05). Prolactinemia did not correlate with this side effect, it correlated with the absence of the menstrual cycle in women.

Inhibin B may be used as a marker of the functional condition in antipsychotic induced sexual dysfunction in men. Results are limited by the sample size. Further study is needed to evaluate the importance and specificity of Inhibin B.