Article BOLD signal Clinical Dementia Rating Hamilton Depression Rating Scale Hospital Anxiety and Depression Scale Mini Mental State Examination Montreal cognitive assessment Parkinson disease REM sleep Unified Parkinson Disease Rating Scale aged amygdala anterior cingulate antidepressant activity antidepressant agent anxiety attention deficit disorder basal ganglion brain cortex brain depth stimulation brain region clinical assessment cognition controlled study corpus callosum depression diffusion tensor imaging diffusion weighted imaging disease duration disease severity