Treatment of Agitation/Psychosis in Dementia/Parkinsonism (TAP/DAP)

The primary aim of this study is to determine the safety and efficacy of quetiapine (Seroquel) for the treatment of psychosis and/or agitation in patients with primary dementia complicated by coexistent parkinsonism, or patients with Parkinson's disease with dementia \[PDD\] who have episodes of agitation or psychosis. The secondary aim is to determine the safety and tolerability, particularly the influence on parkinsonism, of quetiapine when used to treat psychosis and/or agitation in patients with dementia complicated by coexistent parkinsonism.

Psychosis and agitation often occur in the course of dementia and are a major source of patient disability and caregiver stress. For the common situation in which extrapyramidal (parkinsonian) motor dysfunction accompanies dementia, there is a therapeutic dilemma since the most frequently used drugs to treat the behavioral problems, neuroleptic antipsychotics, can worsen parkinsonism and have been associated with severe extrapyramidal reactions in some types of dementia. To date, the efficacy and tolerability of a promising alternative medication class to treat psychosis and agitation, namely atypical antipsychotics, has not been tested in patients with a primary dementia selected for coexisting parkinsonism. This is a multicenter double-blind, controlled clinical trial in which 60 subjects with a primary dementia (probable Alzheimer's disease \[AD\] or probable dementia with Lewy bodies \[DLB\]) and coexisting parkinsonism, or Parkinson's disease with dementia \[PDD\] will be randomized to 1 of 2 treatment groups: (1) quetiapine (QUET); an atypical antipsychotic with a favorable extrapyramidal side effect profile), or (2) placebo. Each subject participates in the trial for 10 weeks and systematic ratings of behavior, motor function, cognition, adverse events and other outcomes occur at baseline and after 6 and 10 weeks of assigned treatment.