Understanding impulsivity in severe depression? A psychometrical contribution

Background: Depression, especially severe depression, is strongly associated with suicidality. Impulsivity is one of the main dimensions of suicidality. The objective of this study was to assess the structure of impulsivity in severe depression and its relationships to suicide attempts. Methods: 127 depressed in-patients were assessed at admission and after 4 weeks of treatment for depression and impulsivity with the Impulsivity Rating Scale (IRS) and the Impulse Control Scale (ICS) or the Baratt Impulsivity Scale (BIS). Results: Three dimensions of impulsivity were evidenced in these severely depressed patients, i.e., behavioral loss of control, nonplanning and cognitive. These three dimensions are state dependent. Recent suicide attempts in severe depression are related to loss of control and cognitive impulsivity but not to nonplanning. IRS ad ICS may assess primarily behavioral impulsivity, i.e., loss of control and nonplanning, whereas BIS may assess primarily cognitive impulsivity. Conclusions: In the future, these three dimensions should be correlated to biological and genetic markers of impulsivity [serotonergic (5-HT) system] and prospective studies should assess the predictive value of the three dimensions of impulsivity in the occurrence of suicide attempts in depressed patients.