Relationship between measures of impulsivity in opioid-dependent individuals

Background: Impulsivity is implicated as a contributing factor to ongoing heroin use. This study aimed to determine the inter-relatedness of a battery of self-reported and performance-based behavioural measures of impulsivity in opioid-dependent individuals. Methods: Seventy-two participants on opioid substitution pharmacotherapy completed a battery of impulsivity measures. We analysed the correlations and factor structure of the impulsivity tasks. Results: We observed correlations between self-report measures, but self-report measures were unrelated to the performance-based tasks. For the performance-based tasks, correlations were only observed between outcome measures of the same task, and between outcome measures of the impulsive decision-making tasks. Principal components analysis revealed five components that we labelled self-reported impulsivity, impulsive decision-making with learning, impulsive decision-making without learning, sensitivity index, and responding without consideration of consequences. Discussion: This study reinforces the distinction between multiple facets of impulsivity. This may assist with comparisons between studies that use different measures of impulsivity, and to design improved treatment interventions that target specific aspects of impulsivity.