Cortical cholinergic denervation is associated with depressive symptoms in Parkinson's disease and parkinsonian dementia

Aim: To investigate the relationship between ratings of depressive symptoms and in vivo cortical acetylcholinesterase (AChE) activity in subjects with Parkinson's disease (PD) and parkinsonian dementia (PDem). Methods: Subjects (with PD, n = 18, including subjects with PDem, n = 6, and normal controls, n = 10) underwent [C-11] methyl-4-piperidinyl propionate AChE positron emission tomography imaging and clinical assessment including the Cornell Scale for Depression in Dementia (CSDD). Results: Subjects with PD and PDem had higher scores on the CSDD compared with normal controls: 7.3 (5.4) and 2.8 (2.6), respectively (F = 6.9, p = 0.01). Pooled analysis demonstrated a significant inverse correlation between cortical AChE activity and CSDD scores: R = 20.5, p = 0.007. This correlation remained significant after controlling for Mini-Mental State Examination scores. Conclusion: Depressive symptomatology is associated with cortical cholinergic denervation in PD that tends to be more prominent when dementia is present.