- Resides in a stable living situation, according to the investigator's judgment, and must have an identified informant who should be consistent throughout the study. If possible, the informant should accompany the subject or be available for in person ratings at the screening, baseline (Day 1), and final study visits. In person informant ratings on all relevant study visits are preferred whenever possible. However, if the informant is not available for in person ratings, telephone interview is acceptable. The informant must be available for a telephone interview throughout the study at all visits. As long as both the informant visit and subject visit are within the study visit windows, it is not necessary that they occur on the same day. The informant must interact with the subject at least 2 times a week.