RecruitingDevice studyLow Voltage Electrical Stimulation for Depression in Parkinson's PatientsThe goal of this clinical trial is to determine the relative efficacy of fMRI model guided Transcranial Direct Current Stimulation (mgTDCS) in improving the depressive symptoms of patients with Parkinson's Disease (PD). The main questions it aims to answer are: 1) Can the use of mgTDCS significantly improve the self-reported level of depression and apathy in patients with PD from pre-intervention to post-intervention compared to a sham control? 2) Can the use of mgTDCS significantly normalize the cortical eeg alpha asymmetry so commonly seen in depressed patients compared to sham mgTDCS? 3) Can the use of mgTDCS significantly improve scores on neuropsychological tests of working memory?