The prevalence of hallucinations and psychosis in PD has increased substantially with the use of levodopa treatment for motor symptoms. Their presence has also been found to increase the risk of death in PD. Factor et al report that the use of atypical antipsychotic therapy has apparently reduced some of morbidity and mortality associated with PD psychosis, on the basis of the finding that 28% of nursing home patients died within 2 years of admission compared with 100% in a study conducted

prior to availability of atypicals; however, psychosis remains a significant problem in the treatment of PD.39 Between 20% and 40% of PD patients will experience Inhibitors,research,lifescience,medical these symptoms at some point during Inhibitors,research,lifescience,medical the course of the illness.40 Hallucinations in PD can be very vivid, and accompanied by either preserved insight, which is not. a state of psychosis, or diminished insight, Ion Channel Ligand Library constituting actual psychosis. In clinical practice, a continuum of insight is seen, a finding that is supported by

research.41 Visual hallucinations are the most, common type of hallucination in PD patients.42-43 People, animals, or objects are often reported, and some patients are amused by these manifestations. The figures disappear when the patient attempts to touch them. A study of 102 consecutive clinic patients diagnosed with PD using strict criteria found that almost. 30% had visual hallucinations or delusions. Symptoms Inhibitors,research,lifescience,medical in four of the patients were found to be secondary to delirium.41 Some data suggest that the presence of Inhibitors,research,lifescience,medical visual hallucinations is stable over time. 1 A large, community-based study of PD patients found certain features associated with increased risk for hallucinations, including advanced age, later stage Inhibitors,research,lifescience,medical of PD, cognitive impairment, and depression.45 The causal role of dopaminergic treatment agents with respect to these symptoms is somewhat, controversial. Psychosis and hallucinations were seen in PD prior to the development of dopaminergic agents, but the prevalence of these symptoms has increased dramatically with the use of such treatments. Most groups feel

that, dopaminergic therapy for the motor symptoms of PD causes the majority of hallucinations and psychosis seen in PD, perhaps by overstimulation of the mesocorticolimbic dopamine system, which may be oversensitive in PD.46 Friedman and Sienkiewicz47 found that patients who have an earlier onset of PD have more complex psychotic complications MTMR9 from dopaminergic therapy and are more likely to develop dyskinesias as a side effect of treatment. The authors suggest that this may be due to the more focal nature of the pathology in young-onset PD patients, where neuropathological change may be primarily in the dopaminergic system.48 Some investigators feel the underlying disarray of the dopaminergic system in PD itself contributes more to development of hallucinations and psychosis.