Discounting and Executive functions as indicators of methamphetamine use in adolescents and adults

Abstract Meth-users have shown low performance in some executive functions tasks.  This low performance can entail problems of control behavior, and increased impulsivity such as preference the small reward over the large delayed one. The current study was aimed to evaluate the performance in three executive tasks (shifting, updating and inhibition), and four discounting tasks (delay and probability) of gains and losses by meth-users and non-users. We worked with 40 male adults (20 meth-users and 20 non-users), and 32 male adolescents (20 meth-users and 12 non-users). We found with CART algorithm that inhibition, updating and probability discounting tasks were the good predictors to identify non users and meth-users. Our general conclusion is the executive functions: Inhibition and Updating are related with cognitive issues due to drug use in a developing brain, and the discounting tasks do not reflect a general impulsivity trait.