Impulsive-Compulsive Behaviours in a German Parkinson's Disease Outpatient Sample

Background: Impulsive-compulsive behaviours (ICBs) are frequent complications of Parkinson's disease (PD), associated with treatment by dopamine agonists (DAs). These include impulse control disorders (ICDs), repetitive behaviour (RB) and the dopamine-dysregulation syndrome (DDS). Methods: A subsample of 72 patients of a large longitudinal study (n = 739) was screened with the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's disease (QUIP). Results were associated with socio-demographic, clinical and neuropsychological parameters. Results: A large proportion of the sample reported ICBs (60 %), RBs were most frequent (47 %). Patients with ICBs consumed higher doses of DAs (343 +/- 177mg vs. 390 +/- 153 mg; p < 0.01). Pramipexole was associated with RB but not ICDs (273 +/- 225mg and 53 +/- 106mg vs. 151 +/- 209mg in patients without ICB). Patients with ICDs reported more dyskinesias (UPDRS IV: 1.78 +/- 1.6 vs. 0.55 +/- 1.1 points; p = 0.012) and patients with multiple ICBs a longer duration of PD (9.3 +/- 5.0 vs. 6.2 +/- 4.0 years; p = 0.026) and worse quality of life (PDQ39: 29.9 +/- 13.8 vs. 20.3 +/- 13.4 points; p = 0.036) compared to patients without any ICB. Conclusions: ICBs are frequent even in outpatients with moderate duration and severity of PD and associated with DA dose. Because of possible serious psychosocial consequences, detecting and managing them is of high importance.