Beyond Dopamine: The Role of the Serotonergic System and Treatments in Understanding and Treating Visual Hallucinations in Parkinson Disease

Abstract

Visual hallucinations (VH) have long been associated with organic brain disease and are a common presentation in a range of reversible and degenerative brain disorders. One of the more common diseases associated with visual hallucinations is Parkinson disease (PD), and visual hallucinations in PD are often complex and detailed. Because patients are frequently distressed by these experiences, treatment of VH is often required. The pharmacological mainstay of the treatment of VH in PD has been antipsychotic medication such as quetiapine, olanzapine, and clozapine. The evidence base for using these medications is limited and their use is based on an underlying assumption that VH result from dop..