Effect of Adjunctive Aripiprazole on Sexual Dysfunction in Schizophrenia: A Preliminary Open-Label Study.

Introduction: Although adjunctive aripiprazole improves hyperprolactinemia, sufficient evidence for its effects on sexual dysfunction has not been obtained. We assessed the usefulness of adjunctive aripiprazole for schizophrenia with sexual dysfunction. Methods: 22 Japanese schizophrenia patients with antipsychotic-induced hyperprolactinemia and sexual dysfunction were enrolled, and 19 of them completed the study. Aripiprazole was administrated in a flexible titration schedule to participants according to the judgment of each doctor, and patients were followed for 24 weeks. Serum prolactin, Clinical Global Impression Scales-Severity (CGI-S), and Nagoya Sexual Function Questionnaire (NSFQ) were measured at baseline and at 4, 8, 12, and 24 weeks. Results: Prolactin at week 4 and later was significantly lower than that at baseline. Compared to baseline, we observed a significant improvement in total sexual dysfunction as measured by NSFQ at week 8 and later. In males, erectile dysfunction was significantly reduced at week 24. In females, menstrual irregularity and galactorrhea were significantly reduced at week 24. CGI-S did not significantly change. Discussion: Although the small sample size is a limitation in this study, adjunctive aripiprazole may be useful treatment for sexual dysfunction including hyperprolactinemia in schizophrenia.

Circadian rhythm of melatonin release in pineal gland culture: arg-vasopressin inhibits melatonin release.

The mammalian pineal gland is known to receive a noradrenergic sympathetic efferent signal from the suprachiasmatic nucleus (SCN) via the superior cervical ganglion. Arg-vasopressin (AVP) containing neurons in the SCN is one of the output paths of circadian information to the other brain areas. AVP release from the SCN is suppressed by melatonin. In turn, we determined the direct effect of AVP on melatonin release using pineal gland explant culture. AVP (1 microM) suppressed melatonin release. Noradrenaline stimulated melatonin release was attenuated by AVP. In turn, the expression of the melatonin synthesis enzyme arylalkylamine N-acetyltransferase mRNA in the rat SCN was reported. We measured melatonin content in the SCN in rats kept under the light-dark cycle and constant dim light. Melatonin in the SCN was higher during the dark period than that in the light. A similar tendency was also observed in the SCN of animals kept under a constant dim light. It was suggested that the reciprocal regulation of melatonin release and AVP release occurs in the SCN and pineal gland.