Predictors of response to a cognitive behavioral intervention for impulse control behaviors in Parkinson's disease

BACKGROUND: Limited trial evidence suggests that cognitive-behavioral therapy (CBT) may be effective in managing impulse control behavior (ICBs) in Parkinson's disease. AIMS: To examine predictors of outcome in trial, participants (N=42) receiving treatment immediately or after a waiting time. METHODS: Dependent variables were Clinical Global Impression of Change (CGI-C) and the Neuropsychiatric Inventory (NPI). Baseline demographic and clinical variables were independent variables. RESULTS: Better CGI-C was predicted by fewer ICBs, taking a dopamine agonist, lower levodopa (l-dopa) equivalent dose (LEDD), higher social functioning, and lower NPI severity before treatment. Improvement on the NPI was predicted by lower LEDD, lower anxiety, lower baseline global clinical severity, and higher social functioning. CONCLUSIONS: Patients with lower burden of ICBs and other psychiatric symptomatology, better social functioning, and lower dose of antiparkinsonian medication may benefit more from CBT. However, we cannot yet identify individual patients with sufficient confidence at this stage to target treatment.