Comparing Antipsychotic Medications in LBD Over Time

This study is comparing two antipsychotic medications — quetiapine and pimavanserin — in people with Lewy body dementia (LBD) or Parkinson's disease who are experiencing hallucinations or other psychotic symptoms. The goal is to find out which drug works better with fewer side effects over time. **You may be eligible if...** - You are a patient seen in a neurology clinic at UT Health San Antonio - You have been diagnosed with psychosis related to Parkinson's disease or Lewy body dementia - You need to start an antipsychotic medication for the first time - Your doctor is equally comfortable prescribing either quetiapine or pimavanserin **You may NOT be eligible if...** - You have a medical reason that prevents you from taking either medication - You are currently taking another antipsychotic drug - You do not have a caregiver available to complete symptom questionnaires Talk to your doctor to see if this trial is right for you.