A positive association between 5HT re-uptake binding sites and depression in dementia with Lewy bodies

Background: Depression is a common and distressing problem in the context of dementia, and is significantly more common in Dementia with Lewy bodies (DLB) than in Alzheimer’s disease. The neurochemical basis for depression in DLB has not been investigated. Aim: To investigate the association between depression and 5HT transporter re-uptake binding in DLB patients. Method: A representative cohort of dementia patients received annual assessments, which included a standardised evaluation of depression until death. At post-mortem, (3H) cyanoimipramine autoradiography was used to quantify 5HT transporter re-uptake sites in the hippocampus and adjacent temporal cortex (Brodmann Area-BA 36, and 20); and parietal neocortex (BA 7a). Results: Twenty-one cases were evaluated neurochemically, of whom seven had experienced a major depressive disorder. Major depression was associated with a significant preservation of 5HT transporter re-uptake sites in the parietal neocortex compared with non-affected cases (BA 7a area 1 t=3.3, P=0.004; BA 7a area 3 t=3.8, P=0.001). Conclusion: This preliminary report is important in challenging some of the assumptions about cortical monoamine functioning in depressed dementia.