Impulsivity and risk-taking in clinical and non-clinical populations

Various aspects of impulsivity, including risk-taking, were investigated by comparing the responses of control groups with those of three populations that were believed to exhibit problems with impulse regulation: those with eating disorders, attention deficit hyperactivity disorder (ADHD) and recreational drug users. Impulsivity was regarded as a multi-dimensional construct, tests were selected or developed to tap into various aspects of impulsivity, including self-report questionnaires, a novel discrete trials delayed reinforcement operant choice paradigm, a novel measure of financial risk-taking, and the continuous performance test which provides measures of both inattention and impulsivity. These tests varied in their ability to discriminate between groups, and the correlations between measures, as in previous studies, were typically low and mostly non-significant. Findings supported the proposal that impulsivity is a multidimensional construct that must be assessed using a wide range of measures including self-report questionnaires and more objective behavioural measures. The profile of effects found in the three targeted groups supported the proposal that impulsivity manifests itself differently in different populations. Women with anorexia nervosa scored low on impulsiveness and venturesomeness, and demonstrated behavioural impulsivity. Recreational drug users scored high on impulsiveness, venturesomeness and risk-taking, whereas ADHD individuals were inattentive and scored high on impulsiveness and risk-taking taking, but not venturesomeness. Overall the findings highlight the complexity of the impulsivity concept and demonstrate the need to acknowledge its multi-dimensional nature by using a variety of tests to capture its variable expression. Whether impulsivity in particular groups reflects state or trait remains to be determined.