In patients with bipolar disorder (BD) or major depressive disorder (MDD), motor impulsivity is a strong predictor of suicidal actions, according to a small retrospective study published in Comprehensive Psychiatry.
Patients with MDD or BD (n=52) were recruited from private practice, a university clinic, or an outpatient clinic of a psychiatric hospital. Among these patients, 26 had a documented suicide attempt (MD+) and 26 had no such documented attempts (MD−). These participants were compared with 80 control subjects with no psychiatric disorders or documented incidents of self-harm. Neuropsychological questionnaires and scales (Barratt Impulsivity Scale and Melbourne Decision Making Questionnaire) were used to assess for decision making, impulsivity, and inhibitory control.
Compared with control patients and patients without a recorded suicide attempt, patients with BD/MDD who had a documented suicide attempt demonstrated significantly higher Barratt Impulsivity Scale motor domain scores (20.64 for MD− vs 26.45 MD+ vs 18.13 for control patients; x2 = 5.040; P =.008) and attentional Barratt Impulsivity Scale impulsivity score (16.77 for MD− vs 21.77 for MD+ vs 14.90 for control patients; x2 = 4.824; P =.010).
According to the findings from the regression analysis, motor impulsivity was the strongest predictor of suicide history (odds ratio, 1.14; 95% CI, 1.00-1.30; P =.049).
Investigators did not control for MD+ suicide methods, which may have influenced decision-making in the patients. Also, considering only Brazilian patients were included in this small analysis, the findings may not generalize to patients residing in other geographical regions.
The researchers comment that the findings from this study suggest “a potential role of impulsivity as a target for clinical interventions and public policy on suicide prevention.”
Ponsoni A, Branco LD, Cotrena C, et al. Self-reported inhibition predicts history of suicide attempts in bipolar disorder and major depression. Compr Psychiatry. 2018;82:89-94.