Impact of Adolescent Alcohol and Drug Use on Neuropsychological Functioning in Young Adulthood: 10-Year Outcomes

Abstract

BACKGROUND: Alcohol and other substance use disorders (AUD/SUD) are common among youth and often continue into adulthood; therefore, the neurocognitive effects of substance use are of great concern. Because neuromaturation continues into young adulthood, youth with AUD/SUD may be at risk for lasting cognitive decrements. This study prospectively examines neuropsychological functioning over 10 years as a function of AUD/SUD history and outcomes. METHODS: The 51 participants consisted of 18 youth with persisting AUD/SUD, 19 youth with remitted AUD/SUD, and 14 community youth with no AUD/SUD history followed over 10 years (ages 16 to 27 on average) with neuropsychological testing and substance use interviews on 8 occasions. Neuropsychological performance from baseline to 10-year follow-up was compared between the three groups. RESULTS: Despite scoring higher than controls at intake, both AUD/SUD groups showed a relative decline in visuospatial construction at 10-year follow-up (p=.001). Regressions showed that alcohol use (β=-.33, p < .01) and drug withdrawal symptoms (β=-.31, p<.05) over follow-up were predictive of year 10 visuospatial function. Alcohol use also predicted verbal learning and memory (β=-.28, p<.05), while stimulant use predicted visual learning and memory function (β=-.33, p=.01). More recent substance use was associated with poorer executive function (β=.28, p<.05). DISCUSSION: These findings confirm prior studies suggesting that heavy, chronic alcohol and other substance use persisting from adolescence to young adulthood may produce cognitive disadvantages, primarily in visuospatial and memory abilities. Youth who chronically consume heavy quantities of alcohol and/or experience drug withdrawal symptoms may be particularly at risk for cognitive deterioration by young adulthood.

Figure 1

Persisting and remitted AUD/SUD groups show reduced Block Design T-Scores from intake to 10-year follow-up, relative to control participants. Note. Each NP measure was normed using T-scores based on the control group's raw scores at intake and year 10. Therefore, the mean of the control group at both time points is T = 50. Error bars depict standard error of the mean.