Verbal learning impairment in adolescents with methamphetamine use disorder: a cross-sectional study

Abstract

Background: Methamphetamine (MA) use has been shown to be associated with deficits in impulsivity, verbal learning, and working memory. Additionally, methamphetamine use disorder (MUD) is related to various brain changes, especially in adolescent users who might be more vulnerable to detrimental effects on brain development. However, little is known about the relationship between adolescent MA use and cognitive impairment. This cross-sectional study aims to explore how the presence of a MUD in adolescents is related to impairments of verbal memory, inhibition, and alertness. Methods: N = 18 psychiatric outpatients with MUD were matched in terms of depressivity, age, and gender to n = 18 adolescents with other substance use disorders (SUDs), as well as n = 18 controls without SUDs. We compared these three groups on the Verbal Learning and Memory Task (VLMT), and the alertness and go/noGo subtests of the Test of Attentional Performance (TAP). Additionally, Spearman’s rank order correlation coefficients were calculated to investigate whether cognitive functioning was directly associated with frequency of past year MA use. Results: The three groups differed significantly in their verbal learning performance (H (2) = 11.7, p =.003, ηp2 =.19), but not in short-term memory, inhibition, cued recall, or alertness. Post hoc tests revealed significant differences in verbal learning between the MA using group and the control group without a SUD (U = 56.5, p =.001, ηp2 =.31). Frequency of past year MA use correlated negatively with short-term memory (ρ = −.25, p