Participants will be randomized to receive either Ketasyn™ or a matching placebo, administered once a day by mixing powder in a glass of liquid. The treatment period will last 90 days, followed by a 2-week washout period. Each patient will be seen 5 times: at screening, baseline, and post-baseline days 45, 90, and 104. The visits will include physical and/or neuropsychological examinations, electrocardiograms (ECGs) and laboratory tests.