DR RV ANAND CONSULTANT NEUROLOGIST SAI NEURO CLINIC ABHIRAMAPURAM NON MOTOR SYMPTOMS IN PARKINSON DISEASE PSYCHOSIS AND HALLUCINATIONS psychosis is defined as a disorder of thinking that causes the person to loose touch with reality.it may occur as a part of treatment due to antiparkinson drugs.the underlying cause ids unknown.visual hallucinations are most commion.it usually becomes more frequent and severe as disease progresses