The serotonin transporter in the midbrain of suicide victims with major depression

Background: The involvement of serotonin in depression and suicide has been proposed, because major depression is successfully treated by medications that specifically block the serotonin transporter and there is evidence for a decrease in serotonin transporters in major depression mid suicide, The midbrain dorsal raphe nucleus (DR) has been implicated as a site for dimini shed serotonergic activity ill that suicide victims with major depression h ave a significant increase in seroronin-1A autoreceptors in the DR. Methods: [H-3]Paroxetine was used to label the serotonin transporter in the subnuclei of the DR at several rostral-to-caudal levels of the midbrain in ten pairs of suicide victims with major depression and age-matched psychia trically normal control subjects. Results: There was a significant increase in serotonin transporters in the entire DR progressing from rostral-to-caudal levels in both normal control subjects and suicide victims with major depression. At compatable rostral-t o-caudal levels, there were no significant differences in [H-3]paroxetine b inding between depressed suicide victims mid normal control subjects in eit her the entire DR or its constituent subnuclei, Conclusions: The pathophysiology of serotonin mechanisms in suicide victims with major depression does not appear to involve alterations in the bindin g of [H-3]paroxetine to the serotonin transporter in the midbrain DR, Biol Psychiatry 2000;47:1015-1024 (C) 2000 Society of Biological Psychiatry.