Psychotic symptoms in Parkinson's disease. From description to etiology

J Neurol. 2005 Jul;252(7):753-64. doi: 10.1007/s00415-005-0918-5.


Psychotic symptoms are common in Parkinson's disease (PD) and occur in at least 20% of medication-treated patients. Benign visual hallucinations usually appear earlier, while malignant hallucinations, confusional states, delusions, paranoid beliefs, agitation, and delirium become more frequent with disease progression. Virtually all antiparkinsonian drugs may produce psychotic symptoms. Cognitive impairment, increased age, disease duration and severity, depression, and sleep disorders have been consistently identified as independent risk factors for their development. Although the precise pathoetiologic mechanisms remain unknown, we review evidence that links ventral dopaminergic pathway dysfunction (overactivity) together with the involvement of other neurotransmitter system imbalances as likely contributors. The clinical importance of the proposed mechanism is that successful management of psychotic symptoms in PD may rely on a multitarget approach to restore neurotransmitter imbalances rather than focusing exclusively on the dopaminergic dysfunction.

Publication types

  • Review

MeSH terms

  • Animals
  • Antiparkinson Agents / therapeutic use
  • Behavioral Symptoms / drug therapy
  • Behavioral Symptoms / epidemiology
  • Behavioral Symptoms / etiology*
  • Behavioral Symptoms / metabolism
  • Brain Chemistry / physiology
  • Humans
  • Parkinson Disease / drug therapy
  • Parkinson Disease / epidemiology
  • Parkinson Disease / physiopathology*
  • Prevalence
  • Psychotic Disorders / drug therapy
  • Psychotic Disorders / epidemiology
  • Psychotic Disorders / etiology*
  • Psychotic Disorders / metabolism
  • Risk Factors


  • Antiparkinson Agents