5-HT receptor function in depression: effect of chronic amitriptyline treatment.

Hypothermic responses to 5-HT receptor activation by the selective ligand ipsapirone (IPS) were attenuated in depressed patients as compared to controls. Chronic treatment with amitriptyline (AMI) further impaired 5-HTmediated hypothermia. The results indicate a subsensitive (presynaptic) 5-HT receptor and/or a defective post-receptor signalling pathway in depression and are consistent with the hypothesis that 5-HT receptors are down-regulted during AMI treatment. [ABSTRACT FROM AUTHOR]