RecruitingPhase 2Drug trialClinical Trial Evaluating the Efficacy and Safety of AGB101 for Treatment of Parkinson's Disease Related PsychosisThis clinical trial will test whether AGB101 (low-dose levetiracetam, 220 mg, extended release tablet) can improve symptoms of psychosis in Parkinson's disease. Participants will be asked to complete up to 5 in-person study visits over approximately 20 weeks. Participants will receive both AGB101 and a placebo to take once a day for 6 weeks, with a 4-week washout in between. Participation will also involve physical/neurological exams, questionnaires, paper and pencil tests, providing blood and urine samples, and completing two MRI exams.