5-HT 2C receptor sensitivity during treatment with selective serotonin re-uptake inhibitors

Abstract

We studied the effect of repeated treatment with selective serotonin re-uptake inhibitors (SSRIs) on the sensitivity of brain 5-HT_2C receptors, by measuring the decrease in slow wave sleep (SWS) that follows administration of meta-chlorophenylpiperazine (mCPP) (7.5 mg orally). mCPP significantly lowered SWS both in patients taking SSRIs and in a group of healthy controls. There was, however, no difference in the response between the two groups. The results do not support the suggestion that repeated SSRI treatment alters the sensitivity of 5-HT_2C receptors in the human brain. The present study, however, cannot exclude the possibility that a decrease in 5-HT_2C receptor sensitivity was offset by higher plasma levels of mCPP in the SSRI-treated group.