Depression in Parkinson's disease: Perspectives from an Australian cohort

Depression is often an under-recognised feature of Parkinson's disease (PD). It is detrimental to physical and interpersonal functioning, negatively impacting a patient's clinical management, quality of life and well-being. We aimed to identify clinical predictors and management implications of depression in Australian PD patients.

103 PD and 81 Healthy Control (HC) subjects were evaluated using the Beck Depression Inventory (BDI) and other validated PD motor and non-motor symptom (NMS) tools.

Nearly twice as many PD patients were depressed, (38.9% vs 20.1%, p = 0.009), with a corresponding increase in depression severity on the BDI (11.9; standard deviation (SD) 8.8 vs 5.2; SD 5.5, p<0.001), and an odds ratio of 2.4 (95% confidence interval 1.2 - 4.7). Employment appeared to be a relative protective factor for depression, whilst patients requiring support services seemed to be more vulnerable to depression. Rapid Eye Movement Sleep Behaviour Disorder, dyskinesias, impulse control disorder, higher daily levodopa equivalent dose, increased motor severity, as well as catechol-O-methyltransferase inhibitor and amantadine use, all showed associations with depression (p<0.05). Chronic pain, decreased physical activity, constipation and upper gastrointestinal dysfunction presented with an apparent increase in risk for developing depression and increased depression severity. Other NMS were also found to be associated with PD-related depression.

Potential selection bias of self-reporting data collection from specialist PD clinics in a single metropolitan area.

Our findings provide novel insight into the prevalence of depression in PD, possible contributory factors and future treatment strategies targeting depression in PD.