Validity of a Self-Rated Method to Identify a Lifetime History of Depression in Parkinson’s Disease

Abstract

Defining depression in Parkinson's disease (PD) is challenging, given the overlap of symptoms between parkinsonism and depression. We recently reported on the validity of two self‐rated depression rating scales in PD.1 These rating scales are useful to identify current depressive status in PD patients, but by themselves, do not identify a lifetime history of depression. We have recently extended our original work, and here we report and validate a self‐rated method to dichotomise PD patients according to their lifetime history of depression. This method can be used in risk factor studies to obtain two extreme groups of ‘ever’ and ‘never’ depressed; as illustrated in our recent genetic study.2