Participants and study design
STOP-PD II
MRS
Water-scaled MRS data were obtained from the National Institute of Mental Health (NIMH) funded STOP-PD II imaging study (R01 MH099167) conducted at the Centre for Addiction and Mental Health in Toronto (CAMH) and University of Massachusetts (UMass). Water-scaled data was not available from the Nathan Kline Institute nor University of Pittsburgh Medical Centre. The study was approved by each institution’s research ethics board/institutional review board.Detailed descriptions of the methods of the randomized clinical trial and the integrated neuroimaging study have been published (Flint et al., 