Background: Impulse control disorders (ICDs) are frequently found in patients with PD treated with dopamine agonists. Despite their name, their relation with impulsivity is not well established.
Objetive: To analyze the relationship between the presence and severity of impulse control disorders (ICDs) in PD and impulsivity.
Methods: Prospective study of 93 consecutive non-demented PD patients. ICDs were assessed using the Questionnaire for Impulsive-Compulsive Disorders (QUIP) and Minnesota Impulsive Disorders Interview (MIDI), and impulsivity using the Barratt Impulsiveness Scale (BIS-11) and commision errors in Conners' Continuous Performance Test II (CCPT).
Results: Thirty-five percent of patients (33/93) presented ICD. Younger age (p < 0.05) and dopamine agonists use (p < 0.05) were associated with presence of ICD but not to severity (p = 0.61 and p = 0.72 respectively). Impulsivity, either self-reported (BIS-11) or estimated by CCPT, did not differ between patients with ICD and without. However, in patients presenting ICD impulsivity measures correlated with ICD severity (p < 0.01 for both measures). There was no relation between impulsivity and dopaminergic medication use. Dose of dopamine agonist was not associated with ICD. Other PD medications were also not associated. Multivariate analysis confirmed significant association between ICD severity and impulsivity (p < 0.001).
Conclusion: Age and dopamine agonist were associated with the presence of ICD, but not with their severity. Conversely, impulsivity was not associated with ICD presence but correlated with severity. This suggests a double dissociation, showing impulsivity as an independent variable explaining ICD severity in patients on treatment with dopamine agonists.
© 2015 Published by Elsevier Inc.