Major depressive disorder in Parkinson’s disease: a cross-sectional study from Sri Lanka

BACKGROUND: Depression is common in Parkinson’s disease (PD), and has a significant impact on the functional level of those affected. It is well studied in Western populations but data from Asia is limited. This study aims to estimate the prevalence of depression among PD patients attending a tertiary care outpatient clinic in Sri Lanka and identify potential risk factors. METHODS: One hundred and four consecutive idiopathic PD patients as defined by the United Kingdom Parkinson’s Disease Society Brain Bank Diagnostic Criteria were recruited to the study. An interviewer administered questionnaire, the Hoehn-Yahr staging scale and the Schwab-England Activities of Daily Living Scale (SEADL) were used for assessment. Depression was diagnosed through a semi-structured clinical interview based on DSM-IV-TR criteria and all subjects were rated with the Montgomery-Asberg Depression Rating Scale (MADRS). RESULTS: The prevalence of depression in the study population was 37.5%. Among the depressed 12 (30.8%) had mild depression, 21 (53.8%) moderate depression and 6 (15.4%) had severe depression. Depression was significantly associated with the stage of PD, functional impairment, civil status, educational level, caregiver dependence and concomitant diabetes mellitus. CONCLUSION: A significant proportion of PD patients suffers from depression. The prevalence rate of depression in the sample was similar to that reported in previous studies. Depression in PD is significantly associated with functional impairment.