Second to fourth digit ratio (2D:4D), impulsivity and aggression levels in patients with opiate use disorder and alcohol use disorder

Abstract

ABSTRACT Objective To compare the ratio of the right and left second and fourth digits (2D:4D), aggression, and impulsivity levels in opiate use disorder (OUD), alcohol use disorder (AUD), and healthy controls. Methods Eighty-four patients diagnosed with OUD, 58 patients diagnosed with AUD, and 58 healthy volunteers were included. Participants administered the sociodemographic data form, Barratt Impulsivity Scale (BIS-11), and Buss-Perry Aggression Questionnaire (BPAQ). Results Healthy controls’ right-hand 2D:4D ratio was higher than the OUD and AUD groups (respectively; p < .001, p < .001). The right-hand 2D:4D ratio was similar between OUD and AUD (p = .542). Left-hand 2D:4D ratio of healthy controls was higher than OUD and AUD groups (respectively; p < .001, p < .001). The left-hand 2D:4D ratio was similar between OUD and AUD (p = .429). The BIS-11 scores of the healthy controls were lower than OUD and AUD groups (respectively; p < .001, p < .001). It was found similar in the AUD and OUD groups (p = .264). The BPAQ scores of the healthy controls were lower than the OUD group and the AUD group (respectively; p < .001, p < .001). It was found similar in the AUD and OUD groups (p = .973). Conclusion It was found that the 2D:4D ratio of both hands in OUD and AUD patients is lower than that of healthy volunteers. The 2D:4D ratio can be an indicator of addiction, regardless of the type of substance used.