a1 Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
The aim of the present clinical positron emission tomography study was to examine if the 5-HTT is a common target, both for tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). Serotonin transporter (5-HTT) occupancy was estimated during treatment with TCA, SSRI and mirtazapine in 20 patients in remission from depression. The patients were recruited from out-patient units and deemed as responders to antidepressive treatment. The radioligand [11C]MADAM was used to determine the 5-HTT binding potential. The mean 5-HTT occupancy was 67% (range 28–86%). There was no significant difference in 5-HTT occupancy between TCA (n=5) and SSRI (n=14). 5-HTT affinity correlated with the recommended clinical dose. Mirtazapine did not occupy the serotonin transporter. The results support that TCAs and SSRIs have a shared mechanism of action by inhibition of 5-HTT.
(Received November 13 2011)
(Reviewed December 07 2011)
(Accepted December 07 2011)
(Online publication January 16 2012)
c1 Address for correspondence: J. Lundberg, M.D., Building R5, Karolinska University Hospital Solna, S-171 76 Stockholm, Sweden. Tel.: +46 8 517 750 13 Fax: +46 8 517 717 53 Email: firstname.lastname@example.org