Neuropsychiatric co-morbidities in non-demented Parkinson's disease

OBJECTIVE: To evaluate neuropsychiatric co-morbidities (depression, psychosis and anxiety) in non-demented patients with Parkinson's disease (PD). BACKGROUND: Non-motor symptoms like neuropsychiatric co-morbidities are common in Parkinson's disease and may predate motor symptoms. Currently there is scarcity of data regarding neuropsychiatry manifestations in Indian patients with PD. METHODS: In this cross-sectional study consecutive 126 non-demented patients with PD (MMSE ≥25) were enrolled. They were assessed using Unified Parkinson's disease rating scale (UPDRS), Hoehn & Yahr (H&Y) stage, Schwab and England (S&E) scale of activity of daily life. Mini-international neuropsychiatric interview (MINI) was used for diagnosis of depression, psychosis and anxiety. Beck's depression inventory (BDI), Brief psychiatric rating scale (BSRS) and Hamilton rating scale for anxiety (HAM-A) scales were used for assessment of severity of depression, psychosis and anxiety respectively. RESULTS: Mean age and duration of disease was 57.9 ± 10.9 years and 7.3 ± 3.6 years respectively. At least one of the neuropsychiatric co-morbidity was present in 64% patients. Depression, suicidal risk, psychosis and anxiety were present in 43.7%, 31%, 23.8% and 35.7% respectively. Visual hallucinations (20.6%) were most frequent, followed by tactile (13.5%), auditory (7.2%) and olfactory hallucinations (1.6%). Patients with depression had higher motor disability (UPDRS-motor score 33.1 ± 14.0 vs 27.3 ± 13.3; and UPDRS-total 50.7 ± 21.8 vs 41.0 ± 20.3, all p values <0.05). Patients with psychosis were older (63.6 ± 8.0 years vs 56.1 ± 11.1 years, p < 0.05) and had longer duration of illness (8.6 ± 3.4 years vs 6.9 ± 3.5, p < 0.05). CONCLUSIONS: About two third patients with Parkinson's disease have associated neuropsychiatric co-morbidities. Depression was more frequent in patients with higher disability and psychosis with longer duration of disease and older age. These co-morbidities need to be addressed during management of patients with PD.