Increased cerebral serotonin-2A receptor binding in depressed patients with myocardial infarction

Serotonin (5-HT) has been implicated in the pathophysiology of depression. It is not known whether depression in post-myocardial infarction (MI) patients is also serotonin-mediated. In somatically healthy depressed persons, increased brain 5-HT2A receptor binding has been reported in some studies. In animal studies, decreased serotonin activity was found after induction of MI. In the present study, it was hypothesized that depressed post-MI patients would exhibit increased brain 5-HT2A receptor binding compared with non-depressed post-MI patients. Single photon emission computed tomography (SPECT) with the radioligand 123I-5-I-R91150, a 5-HT2A receptor antagonist, was used to study 5-HT2A receptor binding. SPECT scans were performed in nine depressed post-MI patients, 10 non-depressed post-MI patients and 10 healthy control subjects. Results were analysed using statistical parametric mapping. Depressed post-MI patients showed increased 5-HT2A receptor binding compared with non-depressed post-MI patients, and MI patients showed decreased 5-HT2A receptor binding compared with control persons. Both post-MI depression and MI seem to be associated with changes in 5-HT2A receptor binding.