Preliminary evaluation of the DDS-PC inventory: a new tool to assess impulsive–compulsive behaviours associated to dopamine replacement therapy in Parkinson’s disease

Dopaminergic medications could increase the occurrence of a set of dysregulated behaviours in Parkinson’s disease (PD), including reward-seeking behaviours (pathological gambling, hypersexuality, compulsive shopping, binge eating, reckless driving), punding and compulsive medication use. We report a preliminary evaluation of a questionnaire to assess the presence of these impulsive–compulsive behaviours associated to dopamine replacement therapy in PD. We screened 38 patients and their caregivers, comparing dopamine dysregulation syndrome (DDS) patients and non-DDS patients. The questionnaire was well accepted and demonstrated a preliminary good discriminant validity (p = 0.000). In addition, clinically relevant dysregulated condition is associated with a younger age (p = 0.006), younger age at disease onset (p = 0.001), levodopa-equivalent daily dose (p = 0.029), UPDRS III (p = 0.021), increased global psychopathology (interpersonal sensitivity and psychoticism), and differences in our inventory (p = 0.000). These preliminary results suggest that the DDS-PC inventory could help to identify patients experiencing impulsive–compulsive behaviours associated to DDS.