Substance use during adolescence continues to be a prevalent concern. Marijuana and alcohol are consistently the most frequently used substances among teens [1], with 16% of 12-17 year-olds reporting lifetime marijuana use, and 15% of 12th graders endorsing past month intake [2]. Rates of past month alcohol use among 12-17 year-olds are similar (16%), with increasing prevalence at ages 16 and 17 (35%). For the estimated 9% of adolescents who meet criteria for substance abuse or dependence [2], harmful effects of marijuana and alcohol span physiological, social, and psychological functioning [3-5]. Because extensive brain maturation occurs during this time, adolescents who use substances are vulnerable to alterations in brain functioning, cognition and behavior.
Recent studies have shown alterations in brain functioning in adolescent substance users even after 28 days of sustained abstinence. These studies indicate weaknesses in neuropsychological functioning in the areas of attention, speeded information processing, spatial skills, learning and memory, and complex behaviors such as planning and problem solving [6-10]. There are also associated changes in brain structure and function that include altered prefrontal brain volumes, reduced white matter microstructural integrity, and atypical brain activation patterns [11-17]. There may be potential reversibility of brain structural changes with long-term abstinence [18], though additional studies are needed to understand the extent to which abnormalities persist or remit with time.
Adolescence is a time of extensive social, psychological, and biological change. There are also considerable academic demands and educational considerations that take place during this time. For youth that engage in heavy substance use, the potential impact of these substances on development warrants concern. Assessment of the adolescent’s neuropsychological functioning can provide valuable insight with regard to potential cognitive weaknesses that may affect academic performance, identify mood and behavioral changes that would benefit from treatment, and provide appropriate recommendations for substance use intervention.
References
1. Schweinsburg, A.D., S.A. Brown, and S.F. Tapert, The influence of marijuana use on neurocognitive functioning in adolescents. Current Drug Abuse Reviews, 2008. 1: p. 99-111.
2. SAMSHA, Results from the 2006 National Survey on Drug Use and Health: National Findings. 2007: Rockville, MD: Office of Applied Studies, DHHS.
3. Macleod, J., et al., Psychological and social sequelae of cannabis and other illicit drug use by young people: a systematic review of longitudinal, general population studies. Lancet, 2004. 363(9421): p. 1579-88.
4. Tucker, J.S., et al., Does solitary substance use increase adolescents' risk for poor psychosocial and behavioral outcomes? A 9-year longitudinal study comparing solitary and social users. Psychology of Addictive Behaviors, 2006. 20(4): p. 363-72.
5. Tucker, J.S., et al., Are drug experimenters better adjusted than abstainers and users?: a longitudinal study of adolescent marijuana use. Journal of Adolescent Health, 2006. 39(4): p. 488-94.
6. Brown, S.A., et al., Neurocognitive functioning of adolescents: effects of protracted alcohol use. Alcoholism: Clinical and Experimental Research, 2000. 24(2): p. 164-71.
7. Medina, K.L., et al., Neuropsychological functioning in adolescent marijuana users: subtle deficits detectable after a month of abstinence. Journal of the International Neuropsychological Society, 2007. 13(5): p. 807-20.
8. Tapert, S.F. and S.A. Brown, Neuropsychological correlates of adolescent substance abuse: four-year outcomes. Journal of the International Neuropsychological Society, 1999. 5(6): p. 481-93.
9. Tapert, S.F. and S.A. Brown, Substance dependence, family history of alcohol dependence and neuropsychological functioning in adolescence. Addiction, 2000. 95(7): p. 1043-53.
10. Tapert, S.F., et al., Substance use and withdrawal: neuropsychological functioning over 8 years in youth. Journal of the International Neuropsychological Society, 2002. 8(7): p. 873-83.
11. Jacobsen, L.K., et al., Functional correlates of verbal memory deficits emerging during nicotine withdrawal in abstinent adolescent cannabis users. Biological Psychiatry, 2007. 61(1): p. 31-40.
12. Schweinsburg, A.D., et al., Abstinent adolescent marijuana users show altered fMRI response during spatial working memory. Psychiatry Research: Neuroimaging, 2008.
13. Schweinsburg, A.D., et al., fMRI response to spatial working memory in adolescents with comorbid marijuana and alcohol use disorders. Drug and Alcohol Dependence, 2005. 79(2): p. 201-10.
14. Tapert, S.F., et al., fMRI measurement of brain dysfunction in alcohol-dependent young women. Alcoholism: Clinical and Experimental Research, 2001. 25(2): p. 236-45.
15. Tapert, S.F., et al., Blood oxygen level dependent response and spatial working memory in adolescents with alcohol use disorders. Alcoholism: Clinical and Experimental Research, 2004. 28(10): p. 1577-86.
16. Tapert, S.F., et al., Functional MRI of inhibitory processing in abstinent adolescent marijuana users. Psychopharmacology (Berl), 2007. 194(2): p. 173-83.
17. Bava, S., et al., Altered white matter microstructure in adolescent substance users. Psychiatry Res, 2009. 173(3): p. 228-37.
18. Delisi, L.E., et al., A preliminary DTI study showing no brain structural change associated with adolescent cannabis use. Harm Reduct Journal, 2006. 3: p. 17.
