It’s common for people with Parkinson’s disease to have depression. Other mental health issues, like hallucinations, paranoia, and delusions, can be side effects of Parkinson's treatments,.
Your doctor will rule out any medical causes for your mental health problems. They’ll then check your blood for any chemical imbalances that might be interfering with your nerve signals.
Your doctor also may check for infections, and how well your kidney, liver, or lungs are working.