A systematic review and meta-analysis of health, functional, and cognitive outcomes in young people who use methamphetamine

Methamphetamine use typically starts in adolescence or young adulthood, and early onset is associated with poor outcomes. However, health, functional, and cognitive outcomes associated with methamphetamine use in young people are poorly understood. Therefore, the aim of this systematic review and meta-analysis was to comprehensively assess the evidence on health, functional, and cognitive outcomes in young people (10-25 years-old) who use methamphetamine. Sixty-six studies were identified, investigating a range of outcomes. Meta-analysis revealed a strong association between conduct disorder and methamphetamine use in youth. Young people who use methamphetamine were also more likely to be involved in the justice system and to perpetrate violence against others than those who did not. Educational problems were also consistently associated with youth methamphetamine use. The most consistently impaired cognitive domain was inhibitory control. Key limitations in the current literature were identified, including heterogenous measurement of exposure and outcomes, lack of adequate controls, and limited causal evidence. Associations identified in the present review will be informative for the development of future research and treatments.