- Visit 4 (week 3): End of Washout/Beginning Treatment Period 2 (60-90 min). All procedures will be performed as described for Visit 3, plus the addition of brain scans. Adherence will be assessed by use of rescue medication documented, and participants will be queried about any side effects experienced. Study medication will be dispensed in sufficient quantities until the next visit. All participants remain with the same treatment assignment as in Period 1.