Some, but not all,
antipsychotics elevate serum
prolactin.
Antipsychotic-induced
hyperprolactinemia is thought to account for high rates of menstrual dysfunction and diminished
estrogen levels in women with
schizophrenia. However, few studies have directly assessed the relationships between
prolactin, menstrual function, and ovarian
hormone levels in this population. Sixteen premenopausal women with
schizophrenia and
schizoaffective disorder, eight treated with an
antipsychotic with
prolactin-elevating potential (five with typical
antipsychotics and three with
risperidone) and eight treated with an
antipsychotic with
prolactin-sparing potential (seven with
olanzapine and one with
clozapine), were studied for eight weeks. Data were collected on menstrual functioning and on serum
prolactin,
estradiol, and
progesterone levels, and were compared between subjects who received an
antipsychotic with
prolactin-elevating potential and an
antipsychotic with
prolactin-sparing potential, and between subjects with
hyperprolactinemia (N=6) and normoprolactinemia (N=10). Additionally, peak ovarian
hormone levels were compared to normal values. While mean
prolactin levels of subjects who received an
antipsychotic with
prolactin-elevating potential were significantly greater than those of subjects who received an
antipsychotic with
prolactin-sparing potential, there were no differences in rates of menstrual dysfunction or in ovarian
hormone values between the two groups. Additionally, similar rates of menstrual dysfunction and ovarian
hormone values were observed between the hyperprolactinemic and normoprolactinemic subjects. Moreover, irrespective of medication type or
prolactin status, most subjects had peak
estradiol levels below normal reference values for the periovulatory phase of the menstrual cycle. While our sample size is small, warranting the need for further investigation, the findings of this preliminary study suggest that
antipsychotic-induced
hyperprolactinemia, alone, may not adequately explain the observed ovarian dysfunction in women with
schizophrenia.