Impaired delay discounting and time sensitivity in methcathinone use disorder.

Substance use disorder (SUD) is characterized by continued drug use despite adverse consequences. Methcathinone is a new type of psychoactive substance that is associated with high excitement and impulsive behaviors. However, it is unclear if individuals with methcathinone use disorders (MCUD) are with impaired decision-making ability. We analyzed the task performance in 45 male MCUD subjects and 35 male matched healthy controls (HC) with intertemporal decision-making task. Constant sensitivity discounting model was used to estimate potential changes in both discounting rate and time sensitivity. The results showed that MCUD individuals exhibited a higher delay discounting rate (p = 0.003, Cohen's d = 0.683) and reduced sensitivity to time (p < 0.001, Cohen's d = 1.662). The delay discounting rate was correlated to the first age for drug use (r = - 0.41, p = 0.004), and the time sensitivity was negatively correlated with the duration of abstinence (r = - 0.31, p = 0.036). We conclude that MCUD individuals are with impaired decision-making ability and time perception disturbances.