Mild Cognitive Impairment in Parkinson's Disease

This study has 2 phases. Each phase will last 10 weeks and there will be a 4-week break between the 2 phases. Thus, you will be enrolled in the study for a total of 24 weeks. Over the course of the 24-week period we will schedule to see you in-person 6 times and check-in with you on the telephone 4 times, 2 times during each phase. Phase I Screening (may be the same day as the baseline visit) - Research personnel will determine if you are eligible to participate in this study. Visit 1 - Baseline Visit, Start Study Medication Phone Call 1 - Check in to see how you are feeling after starting the study medication Visit 2 - 4 Weeks after Baseline, Increase Study Medication if tolerated Phone Call 2 - Check in to see how you are feeling after increasing the study medication Visit 3/ Phase I Termination Visit - 10 Weeks after Baseline (Phase I Termination Visit) 4 Week Break (no study medication) Phase II Visit 4/ Phase II Baseline - 14 Weeks after Baseline, Start Study Medication Phone Call 3 - Check in to see how you are feeling after starting the study medication Visit 5 - 18 Weeks after Baseline, Increase Study Medication Phone Call 4 - Check in to see how you are feeling after increasing the study medication Visit 6/Phase II and Study Termination Visit - 24 Weeks after Baseline Visits 1, 3, 4, and 6 will last for about 2 ½ hours and visits 2 and 5 about 30 minutes. The 'check in' phone calls will last approximately 5-10 minutes. After 24 weeks, your study participation will be over.