Common side effects of aripiprazole include headache, mild nausea, restlessness, sleepiness, or trouble sleeping. Yes, switching from mesoridazine to aripiprazole can help reduce drug-induced Parkinson's symptoms. Aripiprazole is a newer medication designed to have a much lower risk of causing movement-related side effects compared to older treatments like mesoridazine. Since you currently take trihexyphenidyl to manage these movement symptoms, this transition might eventually allow your doctor to lower your trihexyphenidyl dose. Please consult your doctor before making any changes, as they will need to guide you through a safe and gradual transition plan.