Study outcomes in this study included the following: the Rush Hallucination Inventory 7 for hallucinations a modified version of the Pittsburgh Sleep Quality Index (PSQI) for sleep 8 the motor section of the UPDRS (UPDRSm) 6 for assessments of parkinsonism and the Mini-Mental State Examination (MMSE) as a global cognitive assessment. We recruited up to 20 patient/caregiver couples for each baseline stratum to participate in a standardized, structured interview at baseline and sequentially thereafter. Over a 6-month period, screened subjects were categorized into 5 strata, based on their response to the thought disorder item of the UPDRS: 0 = normal behavior without sleep problems or hallucinations 1 = sleep fragmentation only 2 = altered dream phenomena, vivid dreams, or nightmares 3 = hallucinations with retained insight 4 = hallucinations without retained insight.

6 Patients without a 24-hour caregiver or with concomitant strokes, AD, delirium, delusions, or neuroleptic treatment were excluded.

Using computerized randomization methods based on outpatient appointment time, we screened patients with PD (defined by the presence of at least 3 of 4 cardinal features: tremor, bradykinesia, rigidity, postural reflexes) on levodopa treatment (Hoehn & Yahr stage 2 or 3 when ON) with a modified version of the thought disorder item from the Unified Parkinson's Disease Rating Scale (UPDRS).

Hallucination disorder