[Pimavanserin: a new treatment for the Parkinson's disease psychosis]. / Pimavanserine: een nieuwe behandeling voor psychose bij de ziekte van Parkinson.

BACKGROUND: Clozapine is an effective drug for treating psychosis in Parkinson's disease (PDP) and is registered as such in the Netherlands. However, clozapine can have adverse effects, including agranulocytosis. The new drug pimavanserin was recently registered in the United States for the treatment of PDP.
AIM: To review the literature on pimavanserin and discuss the position it currently occupies in the Netherlands as a potential treatment for PDP.
METHOD: Systematic search of the literature.
RESULTS: We found reports on four randomised controlled trials (RCTs), one review and six articles about the pharmacokinetics and pharmacodynamics of pimavanserin. Pimavanserin is an effective treatment for PDP, and, like clozapine, it has very few negative effects on motor skills. However, all of the RCTs were funded by the manufacturer of pimavanserin and the trials were conducted in a very selective patient population. This means that results cannot be generalised. Long-term results are not yet available. In earlier trials clozapine was shown to have a greater and faster antipsychotic effect. Many clinicians and psychiatrists have a great deal of experience with this drug. Another important point is that no-one has yet conducted a trial comparing clozapine and pimavanserin.
CONCLUSION: Given that the current second drug of choice, namely quetiapine, has not been found to be effective for PDP, we are of the opinion that - if pimavanserin is registered in the Netherlands - pimavanserin could be used when the current drug of choice, clozapine, is not completely effective or is poorly tolerated. For patients who have cognitive impairments in addition to psychosis, we advise testing the patient's reaction to a cholinesterase inhibitor before starting the patient on a course of antipsychotics.

Implicit and explicit affective associations towards cannabis use in patients with recent-onset schizophrenia and healthy controls.

BACKGROUND: Cannabis use is common in patients with recent-onset schizophrenia and this is associated with poor disease outcome. More insight in the cognitive-motivational processes related to cannabis use in schizophrenia may inform treatment strategies. The present study is the first known to compare implicit and explicit cannabis associations in individuals with and without psychotic disorder. METHOD: Participants consisted of 70 patients with recent-onset psychotic disorder and 61 healthy controls with various levels of cannabis use. Three Single-Category Implicit Association Tests (SC-IAT) were used to assess 'relaxed', 'active' and 'negative' implicit associations towards cannabis use. Explicit expectancies of cannabis use were assessed with a questionnaire using the same words as the SC-IAT. RESULTS: There were no differences in implicit associations between patients and controls; however, patients scored significantly higher on explicit negative affect expectancies than controls. Both groups demonstrated strong negative implicit associations towards cannabis use. Explicit relaxed expectancies were the strongest predictors of cannabis use and craving. There was a trend for implicit active associations to predict craving. CONCLUSIONS: The findings indicate that patients suffering from schizophrenia have associations towards cannabis similar to controls, but they have stronger negative explicit cannabis associations. The strong negative implicit associations towards cannabis could imply that users of cannabis engage in a behaviour they do not implicitly like. Explicit relaxing expectancies of cannabis might be an important mediator in the continuation of cannabis use in patients and controls.