Brain serotonin(1A) receptor binding measured by positron emission tomography with [C-11]WAY-100635 - Effects of depression and antidepressant treatment

Background: Pharmacological and postmortem investigations suggest that pati ents with major depressive disorder have alterations in function or density of brain serotonin(1A) (5-HT1A) receptors. The aim of the present study wa s to use positron emission tomography with the selective 5-HT1A receptor an tagonist [C-11]WAY-100635 to measure 5-HT1A receptor binding in depressed p atients before and during treatment with selective serotonin reuptake inhib itors. Methods: Position emission tomographic scans with [C-11]WAY-100635 were per formed on 25 patients with major depressive disorder. These included 15 unm edicated depressed patients. Ten of these unmedicated patients were scanned again during selective serotonin reuptake inhibitor treatment. A further 1 0 patients with major depressive disorder were scanned on one occasion only while taking selective serotonin reuptake inhibitors. Comparisons were mad e with [C-11]WAY-100635 positron emission tomographic scans in 18 healthy v olunteer subjects. Region of interest analysis and statistical parametric m apping were performed on binding potential images generated using a referen ce tissue model. Results: Binding potential values were reduced across many of the regions e xamined, including frontal, temporal, and limbic cortex in both unmedicated and medicated depressed patients compared with healthy volunteers. Binding potential values in medicated patients were similar to those in unmedicate d patients. Conclusions: Major depressive disorder is associated with a widespread redu ction in 5-HT1A receptor binding. This reduced 5-HT1A receptor binding was not changed by selective serotonin reuptake inhibitor treatment.