Elevated serotonin transporter binding in depressed patients with Parkinson's disease:: A preliminary PET study with [11C]DASB

This study investigated whether abnormalities in serotonin transporter binding occur in Parkinson's disease (PD) patients with concurrent depression. We estimated serotonin transporter levels in seven clinically depressed early-stage PD patients and in seven healthy matched-control subjects during a single positron emission tomography (PET) scan with the serotonin transporter radioligand, [C-11]DASB. Depressed PD patients displayed a wide-spread increase (8-68%) in [C-11]DASB specific binding outside of the striatum, which was significant in dorsolateral (37%) and prefrontal (68%) cortices. Elevated [C-11]DASB binding was positively correlated with depressive symptoms but not with disease severity or duration. Compatible with recent PET/[C-11]DASB findings in major depression, the present preliminary data suggest that increased [C-11]DASB binding, possibly reflecting greater serotonin transporter density (up-regulation), might be a pathological feature of depression in Parkinson's disease-and possibly a characteristic of depressive illness in general. (C) 2008 Movement Disorder Society.