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Neuropsychological functioning in adolescent marijuana users: Subtle deficits detectable after a month of abstinence

Published online by Cambridge University Press:  14 August 2007

KRISTA LISDAHL MEDINA
Affiliation:
Department of Psychiatry, University of California, San Diego, California Psychology Department, VA San Diego Healthcare System, San Diego, California
KAREN L. HANSON
Affiliation:
Psychology Department, VA San Diego Healthcare System, San Diego, California Department of Psychology, San Diego State University, California
ALECIA D. SCHWEINSBURG
Affiliation:
Psychology Department, VA San Diego Healthcare System, San Diego, California Department of Psychology, University of California, San Diego, California
MAIRAV COHEN-ZION
Affiliation:
Department of Psychiatry, University of California, San Diego, California Psychology Department, VA San Diego Healthcare System, San Diego, California
BONNIE J. NAGEL
Affiliation:
Department of Psychiatry, Oregon Health and Science University, Portland, Oregon
SUSAN F. TAPERT
Affiliation:
Department of Psychiatry, University of California, San Diego, California Psychology Department, VA San Diego Healthcare System, San Diego, California

Abstract

In adults, studies examining the long-lasting cognitive effects of marijuana use demonstrate subtle deficits in attention, executive function, and memory. Because neuromaturation continues through adolescence, these results cannot necessarily generalize to adolescent marijuana users. The goal of this study was to examine neuropsychological functioning in abstinent marijuana using and demographically similar control adolescents. Data were collected from 65 adolescent marijuana users (n = 31, 26% females) and controls (n = 34, 26% females) 16–18 years of age. Extensive exclusionary criteria included independent psychiatric, medical, and neurologic disorders. Neuropsychological assessments were conducted after > 23 days of monitored abstinence. After controlling for lifetime alcohol use and depressive symptoms, adolescent marijuana users demonstrated slower psychomotor speed (p < .05), and poorer complex attention (p < .04), story memory (p < .04), and planning and sequencing ability (p < .001) compared with controls. Post hoc analysis revealed that the number of lifetime marijuana use episodes was associated with poorer cognitive function, even after controlling for lifetime alcohol use. The general pattern of results suggested that, even after a month of monitored abstinence, adolescent marijuana users demonstrate subtle neuropsychological deficits compared with nonusers. It is possible that frequent marijuana use during adolescence may negatively influence neuromaturation and cognitive development. (JINS, 2007, 13, 807–820.)

Type
Research Article
Copyright
2007 The International Neuropsychological Society

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References

REFERENCES

Aasly, J., Storsaeter, O., Nilsen, G., Smevik, O., & Rinck, P. (1993). Minor structural brain changes in young drug abusers. Acta Neurologica Scandinavica, 87, 210214.Google Scholar
Agosti, V., Edward, N., & Frances, L. (2002). Rates of psychiatric comorbidity among U.S. residents with lifetime cannabis dependence. American Journal of Drug and Alcohol Abuse, 28, 643652.Google Scholar
Aronowitz, B., Liebowitz, M.R., Hollander, E., Fazzini, E., Durlach-Misteli, C., Frenkel, M., Mosovich, S., Garfinkel, R., Saoud, J., & DelBene, D. (1994). Neuropsychiatric and neuropsychological findings in conduct disorder and attention-deficit hyperactivity disorder. The Journal of Neuropsychiatry and Clinical Neurosciences, 6, 245249.Google Scholar
Beck, A.T. (1978). Beck Depression Inventory (BDI). San Antonio, TX: Psychological Corp.
Belue, R.C., Howlett, A.C., Westlake, T.M., & Hutchings, D.E. (1995). The ontogeny of cannabinoid receptors in the brain of postnatal and aging rats. Neurotoxicology and Teratology, 17, 2530.Google Scholar
Benes, F.M., Turtle, M., Khan, Y., & Farol, P. (1994). Myelination of a key relay zone in the hippocampal formation occurs in the human brain during childhood, adolescence, and adulthood. Archives of General Psychiatry, 51, 477484.Google Scholar
Block, R.I., O'Leary, D.S., Ehrhardt, J.C., Augustinack, J.C., Ghoneim, M.M., Arndt, S., & Hall, J.A. (2000). Effects of frequent marijuana use on brain tissue volume and composition. Neuroreport, 11, 491496.Google Scholar
Block, R.I., O'Leary, D.S., Hichwa, R.D., Augustinack, J.C., Boles Ponto, L.L., Ghoneim, M.M., Arndt, S., Hurtig, R.R., Watkins, G.L., Hall, J.A., Nathan, P.E., & Andreasen, N.C. (2002). Effects of frequent marijuana use on memory related regional cerebral blood flow. Pharmacology, Biochemistry, and Behavior, 72, 237250.Google Scholar
Bolla, K.I., Brown, K., Eldreth, D., Tate, K., & Cadet, J.L. (2002). Dose-related neurocognitive effects of marijuana use. Neurology, 59, 13371343.Google Scholar
Brown, S.A., Myers, M.G., Lippke, L., Tapert, S.F., Stewart, D.G., & Vik, P.W. (1998). Psychometric evaluation of the Customary Drinking and Drug Use Record (CDDR): A measure of adolescent alcohol and drug involvement. Journal of Studies on Alcohol 1998, 59, 427438.Google Scholar
Cahalan, D., Cisin, I.H., & Crossley, H.M. (1969). American drinking practices: A national study of drinking behavior and attitudes. New Brunswick, NJ: Rutgers Center of Alcohol Studies.
Carlin, A.S. & Trupin, E.W. (1977). The effect of long-term chronic marijuana use on neuropsychological functioning. The International Journal of the Addictions, 12, 617624.Google Scholar
Carta, G., Nava, F., & Gessa, G.L. (1998). Inhibition of hippocampal acetylcholine release after acute and repeated Δ9-tetrahydrocannabinol in rats. Brain Research, 809, 14.Google Scholar
Cha, Y.M., White, A.M., Kuhn, C.M., Wilson, W.A., & Swartzwelder, H.S. (2006). Differential effects of delta(9)-THC on learning in adolescent and adult rats. Pharmacology, Biochemistry, and Behavior, 83, 448455.Google Scholar
Chan, G.C., Hinds, T.R., Impey, S., & Storm, D.R. (1998). Hippocampal neurotoxicity of Delta9-tetrahydrocannabinol. Journal of Neuroscience, 18, 53225332.Google Scholar
Cherek, D.R., Lane, S.D., & Dougherty, D.M. (2002). Possible amotivational effects following marijuana smoking under laboratory conditions. Experimental and Clinical Psychopharmacology, 10, 2638.Google Scholar
Childers, S.R. & Breivogel, C.S. (1998). Cannabis and endogenous cannabinoid systems. Drug and Alcohol Dependence, 51, 173187.Google Scholar
Consroe, P., Carlini, E.A., Zwicker, A.P., & Lacerda, L.A. (1979). Interaction of cannabidiol and alcohol in humans. Psychopharmacology (Berlin), 66, 4550.Google Scholar
Croft, R.J., Mackay, A.J., Mills, A.T., & Gruzelier, J.G. (2001). The relative contributions of ecstasy and cannabis to cognitive impairment. Psychopharmacology, 153, 373379.Google Scholar
Delis, D.C., Jacobson, M., Bondi, M.W., Hamilton, J.M., & Salmon, D.P. (2003). The myth of testing construct validity using factor analysis or correlations with normal or mixed clinical populations: Lessons from memory assessment. Journal of the International Neuropsychological Society, 9, 936946.Google Scholar
Delis, D.C. & Kaplan, E. (2000). Delis-Kaplan Executive Functioning Scale Manual. San Antonio, Texas: Psychological Corporation.
Delis, D.C., Kramer, J.H., Kaplan, E., & Ober, B.A. (2001). California Verbal Learning Test-Second Edition. San Antonio, Texas: The Psychological Corporation.
Egerton, A., Allison, C., Brett, R.B., & Pratt, J.A. (2006). Cannabinoids and prefrontal cortical function: Insights from preclinical studies. Neuroscience and Biobehavioral Reviews, 30, 680695.Google Scholar
Ehrenreich, H., Rinn, T., Kunert, H.J., Moeller, M.R., Poser, W., Schilling, L., Gigerenzer, G., & Hoehe, M.R. (1999). Specific attentional dysfunction in adults following early start of cannabis use. Psychopharmacology, 142, 295301.Google Scholar
Eldreth, D.A., Matochik, J.A., Cadet, J.L., & Bolla, K.I. (2004). Abnormal brain activity in prefrontal brain regions in abstinent marijuana users. Neuroimage, 23, 914920.Google Scholar
Fried, P.A., Watkinson, B., & Gray, R. (2005). Neurocognitive consequences of marijuana: A comparison with pre-drug performance. Neurotoxicology and Teratology, 27, 231239.Google Scholar
Ghozland, S., Aguado, F., Espinosa-Parrilla, J.F., Soriano, E., & Maldonado, R. (2002). Spontaneous network activity of cerebellar granule neurons: Impairment by in vivo chronic cannabinoid administration. European Journal of Neuroscience, 16, 641651.Google Scholar
Giedd, J.N., Snell, J.W., Lange, N., Rajapakse, J.C., Casey, B.J., Kozuch, P.L., Vaituzis, A.C., Vauss, Y.C., Hamburger, S.D., Kaysen, D., & Rapoport, J.L. (1996). Quantitative magnetic resonance imaging of human brain development: Ages 4–18. Cerebral Cortex, 6, 551560.Google Scholar
Gogtay, N., Giedd, J.N., Lusk, L., Hayashi, K.M., Greenstein, D., Vaituzis, A.C., Nugent, T.F., III, Herman, D.H., Clasen, L.S., Toga, A.W., Rapoport, J.L., & Thompson, P.M. (2004). Dynamic mapping of human cortical development during childhood through early adulthood. Proceedings of the National Academy of Science, 101, 81748179.Google Scholar
Grant, I., Gonzalez, R., Carey, C.L., Natarajan, L., & Wolfson, T. (2003). Nonacute (residual) neurocognitive effects of cannabis use: A meta analytic study. Journal of the International Neuropsychological Society, 9, 679689.Google Scholar
Gronwall, D.M.A. (1974). Paced Auditory Serial-Addition Task: A measure of recovery from concussion. Perceptual and Motor Skills, 44, 367373.Google Scholar
Gruber, S.A. & Yurgelun-Todd, D.A. (2005). Neuroimaging of marijuana smokers during inhibitory processing: A pilot investigation. Brain Research, Cognitive Brain Research, 23, 107118.Google Scholar
Harper, J.W., Health, R.G., & Myers, W.A. (1977). Effects of cannabis sativa on ultrastructure of the synapse in monkey brain. Journal of Neuroscience Research, 3, 8793.Google Scholar
Heath, R.G., Fitzjarrell, A.T., & Fontana, C.J. (1980). Cannabis sativa: Effects of brain function and ultrastructure in rhesus monkeys. Biological Psychiatry, 15, 657690.Google Scholar
Hollingshead, A.B. (1965). Two-factor index of social position. New Haven, CT: Yale University Press.
Huttenlocher, P.R. (1990). Morphometric study of human cerebral cortex development. Neuropsychologia, 28, 517527.Google Scholar
Jacobsen, L.K., Mencl, W.E., Westerveld, M., & Pugh, K.R. (2004). Impact of cannabis use on brain function in adolescents. Annals of the New York Academy of Science, 1021, 384390.Google Scholar
Jacobsen, L.K., Pugh, K.R., Constable, RT., Westerveld, M., & Mencl, W.E. (2007). Functional correlates of verbal memory deficits emerging during nicotine withdrawal in abstinent adolescent cannabis users. Biological Psychiatry, 61, 3140.Google Scholar
Jernigan, T. & Gamst, A. (2005). Changes in volume with age: Consistency and interpretation of observed effects. Neurobiology of Aging, 26, 12711274.Google Scholar
Jernigan, T.L. & Tallal, P. (1990). Late childhood changes in brain morphology observable with MRI. Developmental Medicine and Child Neurology, 32, 379385.Google Scholar
Jernigan, T.L., Trauner, D.A., Hesselink, J.R., & Tallal, P.A. (1991). Maturation of human cerebrum observed in vivo during adolescence. Brain, 114, 20372049.Google Scholar
Johnston, L.D., O'Malley, P.M., Bachman, J.G., & Schulenberg, J.E. (2005). Monitoring the Future national results on adolescent drug use, 1975–2004: Vol. 1. Secondary school students (NIH Publication No. 05-5727). Bethesda, MD: National Institute on Drug Abuse.
Kanayama, G., Rogowska, J., Pope, H.G., Gruber, S.A., & Yurgelun-Todd, D.A. (2004). Spatial working memory in heavy cannabis users: A functional magnetic resonance imaging study. Psychopharmacology, 176, 239247.Google Scholar
Kempel, P., Lampe, K., Parnefjord, R., Hennig, J., & Kunert, H.J. (2003). Auditory-evoked potentials and selective attention: Different ways of information processing in cannabis users and controls. Neuropsychobiology, 48, 95101.Google Scholar
Kruesi, M.J., Casanova, M.F., Mannheim, G., & Johnson-Bilder, A. (2004). Reduced temporal lobe volume in early onset conduct disorder. Psychiatry Research: Neuroimaging, 132, 111.Google Scholar
Landfield, P.W., Cadwallader, L.B., & Vinsant, S. (1988). Quantitative changes in hippocampal structure following long-term exposure to delta 9-tetrahydrocannabinol: Possible mediation by glucocorticoid systems. Brain Research, 443, 4762.Google Scholar
Lane, S.D., Cherek, D.R., Pietras, C.J., & Steinberg, J.L. (2005). Performance of heavy marijuana-smoking adolescents on a laboratory measure of motivation. Addictive Behaviors, 30, 815828.Google Scholar
Lane, S.D., Cherek, D.R., Tcheremissine, O.V., Steinberg, J.L., & Sharon, J.L. (2006). Response perseveration and adaptation in heavy marijuana-smoking adolescents. Addictive Behaviors, 32, 977990.Google Scholar
Lenroot, R.K. & Giedd, J.N. (2006). Brain development in children and adolescents: Insights from anatomical magnetic resonance imaging. Neuroscience and Biobehavioral Reviews, 30, 718729.Google Scholar
Lezak, M.D., Howieson, D.B., & Loring, D.W. (2004). Neuropsychological assessment. (4th ed). New York: Oxford University Press.
Loeber, R.T. & Yurgelun-Todd, D.A. (1999). Human neuroimaging of acute and chronic marijuana use: Implications for frontocerebellar dysfunction. Human Psychopharmacology-Clinical and Experimental, 14, 291304.Google Scholar
Lundqvist, T., Jönsson, S., & Warkentin, S. (2001). Frontal lobe dysfunction in long-term cannabis users. Neurotoxicology and Teratology, 23, 437443.Google Scholar
Lynskey, M. & Hall, W. (2000). The effects of adolescent cannabis use on educational attainment: A review. Addiction, 95, 16211630.Google Scholar
Lyons, M.J., Bar, J.L., Panizzon, M.S., Toomey, R., Eisen, S., Xian, H., & Tsuang, M.T. (2004). Neuropsychological consequences of regular marijuana use: A twin study. Psychological Medicine, 34, 12391250.Google Scholar
Martin, C.S., Kaczynski, N.A., Maisto, S.A., & Tarter, R.E. (1996). Polydrug use in adolescent drinkers with and without DSM-IV alcohol abuse and dependence. Alcoholism: Clinical & Experimental Research, 20, 10991108.Google Scholar
Matochik, J.A., Eldreth, D.A., Cadet, J.L., & Bolla, K.I. (2005). Altered brain tissue composition in heavy marijuana users. Drug and Alcohol Dependence, 77, 2330.Google Scholar
Medina, K.L., Nagel, B.J., McQueeny, T., Park, A., & Tapert, S.F. (2007a). Depressive symptoms in adolescents: Associations with white matter volume and marijuana use. Journal of Child Psychology and Psychiatry, 48, 592600.Google Scholar
Medina, K.L., Schweinsburg, A.D., Cohen-Zion, M., Nagel, B.J., & Tapert, S.F. (2007b). Effects of alcohol and combined marijuana and alcohol use during adolescence on hippocampal asymmetry. Neurotoxicology and Teratology, 29, 141152.Google Scholar
Misner, D.L. & Sullivan, J.M. (1999). Mechanism of cannabinoid effects on long-term potentiation and depression in hippocampal CA1 neurons. The Journal of Neuroscience, 19, 67956805.Google Scholar
Monti, P.M., Miranda, R., Nixon, K., Sher, K.J., Swartzwelder, H.S., Tapert, S.F., White, A., & Crews, F.T. (2005). Adolescence: Booze, brains, and behavior. Alcoholism: Clinical and Experimental Research, 29, 207220.Google Scholar
Nagel, B.J., Medina, K.L., Yoshii, J., Schweinsburg, A.D., Moadab, I., & Tapert, S.F. (2006). Age related changes in prefrontal white matter volume across adolescence. Neuroreport, 17, 14271431.Google Scholar
Nigg, J.T., Glass, J.M., Wong, M.M., Poon, E., Jester, J.M., Fitzgerald, H.E., Puttler, L.I., Adams, K.M., & Zucker, R.A. (2004). Neuropsychological executive functioning in children at elevated risk for alcoholism: Findings in early adolescence. Journal of Abnormal Psychology, 113, 302314.Google Scholar
Nixon, S.J. (1999). Neurocognitive performance in alcoholics: Is polysubstance abuse important? American Psychological Society, 10, 181185.Google Scholar
Paus, T., Zijdenbos, A., Worsley, K., Collins, D.L., Blumenthal, J., Giedd, J.N., Rapoport, J.L., & Evans, A.C. (1999). Structural maturation of neural pathways in children and adolescents: In vivo study. Science, 283, 19081911.Google Scholar
Pfefferbaum, A., Mathalon, D.H., Sullivan, E.V., Rawles, J.M., Zipursky, R.B., & Lim, K.O. (1994). A quantitative magnetic resonance imaging study of changes in brain morphology from infancy to late adulthood. Archives of Neurology, 51, 874887.Google Scholar
Pope, H.G., Jr., Gruber, A.J., Hudson, J.I., Cohane, G., Huestis, M.A., & Yurgelun-Todd, D. (2003). Early-onset cannabis use and cognitive deficits: What is the nature of the association? Drug and Alcohol Dependence, 69, 303310.Google Scholar
Pope, H.G., Jr., Gruber, A.J., Hudson, J.I., Huestis, M.A., & Yurgelun-Todd, D. (2002). Cognitive measures in long-term cannabis users. Journal of Clinical Pharmacology, 42, 41S47S.Google Scholar
Pope, H.G., Jr., Gruber, A.J., Hudson, J.I., Huestis, M.A., & Yurgelun-Todd, D. (2001). Neuropsychological performance in long term cannabis users. Archives of General Psychiatry, 58, 909915.Google Scholar
Pope, H.G., Jr., Jacobs, A., Mialet, J.P., Yurgelun-Todd, D., & Gruber, S. (1997). Evidence for a sex-specific residual effect of cannabis on visuospatial memory. Psychotherapy and Psychosomatics, 66, 179184.Google Scholar
Pope, H.G., Jr. & Yurgelun-Todd, D. (1996). The residual cognitive effects of heavy marijuana use in college students. Journal of the American Medical Association, 275, 521527.Google Scholar
Rey, A. & Osterrieth, P.A. (1993). Translations of excerpts from Andre Rey's “Psychological examination of traumatic encephalopathy” and P.A. Osterrieth's “The complex figure copy test” (J. Corwin & F.W. Bylsma, Trans.) The Clinical Neuropsychologist, 7, 321.Google Scholar
Rice, J.P., Reich, T., Bucholz, K.K., Neuman, R.J., Fishman, R., Rochberg, N., Hesselbrock, V.M., Numberger, J.I., Schuckit, M.A., & Begleiter, H. (1995). Comparison of direct interview and family history diagnoses of alcohol dependence. Alcoholism: Clinical and Experimental Research, 19, 10181023.Google Scholar
Robins, L., Cottler, L., Bucholz, K., & Compton, W. (1996). The Diagnostic Interview Schedule, Version 4.0. (DIS 4.0). St. Louis, MO: Washington University of Medicine.
Romero, J., Garcia, L., Fernandez-Ruiz, J.J., Cebeira, J., & Ramos, J.A. (1995). Changes in rat brain cannabinoid binding sites after acute or chronic exposure to their endogenous agonist, anandamide, or to Δ9-Tetrahydrocannabinol. Pharmacology, Biochemistry, and Behavior, 51, 731737.Google Scholar
Rubino, T., Patrini, G., Perenti, M., Massi, P., & Paroloro, D. (1997). Chronic treatment with a synthetic cannabinoid CP-55, 940 alters G-protein expression in the rat central nervous system. Molecular Brain Research, 44, 191197.Google Scholar
SAMHSA. (2004). Results from the 2003 National Survey on Drug Use and Health: National Findings. Rockville, MD: Office of Applied Studies, DHHS.
Schaeffer, J., Andrysiak, T., & Ungerleider, J.T. (1981). Cognition and long-term use of ganja (Cannabis). Science, 213, 465466.Google Scholar
Schneider, M. & Koch, M. (2003). Chronic pubertal but not adult chronic cannabinoid treatment impairs sensorimotor gating, recognition memory and performance in a progressive ratio task in adult rats. Neuropsychopharmacology, 28, 17601790.Google Scholar
Schwartz, R.H., Gruenewald, P.J., Klitzner, M., & Fedio, P. (1989). Short-term memory impairment in cannabis-dependent adolescents. American Journal of Diseases in Children, 143, 12141219.Google Scholar
Schweinsburg, A.D., Nagel, B.N., & Tapert, S.F. (2005). fMRI reveals alteration of spatial working memory networks across adolescence. Journal of the International Neuropsychological Society, 11, 631644.Google Scholar
Shaffer, D., Fisher, P., Lucas, C.P., Dulcan, M.K., & Schwab-Stone, M.E. (2000). NIMH Diagnostic Interview Schedule for Children Version IV (NIMH DISC-IV): Description, differences from previous versions, and reliability of some common diagnoses. Journal of the American Academy of Child & Adolescent Psychiatry. 39, 2838.Google Scholar
Sobell, L.C. & Sobell, M.B. (1992). Timeline follow-back: A technique for assessing self-reported alcohol consumption. In Z. Raye & J.P.A. Litten, (Eds.), Measuring alcohol consumption: Psychosocial and biochemical methods. Totowa, NJ: Humana Press, Inc.
Solowij, N., Stephens, R.S., Roffman, R.A., Babor, T., Kadden, R., Miller, M., Christiansen, K., McRee, B., & Vendetti, J. (2002). Cognitive functioning of long term heavy cannabis users seeking treatment. Journal of the American Medical Association, 287, 11231131.Google Scholar
Sowell, E.R., Thompson, P.M., Holmes, C.J., Jernigan, T.L., & Toga, A.W. (1999). In vivo evidence for post adolescent brain maturation in frontal and striatal regions. Nature Neuroscience, 2, 859861.Google Scholar
Sowell, E.R., Thompson, P.M., Leonard, C.M., Welcome, S.E., Kan, E., & Toga, A.W. (2004). Longitudinal mapping of cortical thickness and brain growth in normal children. The Journal of Neuroscience, 24, 82238231.Google Scholar
Sowell, E.R., Trauner, D.A., Gamst, A., & Jernigan, T.L. (2002). Development of cortical and subcortical brain structures in childhood and adolescence: A structural MRI study. Developmental Medicine and Child Neurology, 44, 416.Google Scholar
Spear, L.P. (2000). The adolescent brain and age-related behavioral manifestations. Neuroscience and Biobehavioral Reviews, 24, 417463.Google Scholar
Spielberger, C.D., Gorsuch, R.L., & Lushene, R.E. (1970). Manual for the State-Trait Anxiety Inventory. Palo Alto: Consulting Psychologists Press, Inc.
Stewart, D.G. & Brown, S.A. (1995). Withdrawal and dependency symptoms among adolescent alcohol and drug abusers. Addiction, 90, 627635.Google Scholar
Stiglick, A. & Kalant, H. (1982). Learning impairment in radial-arm maze following cannabis treatment in rats. Psychopharmacology, 77, 117123.Google Scholar
Stiglick, A. & Kalant, H. (1985). Residual effects of chronic cannabis treatment on behavior in mature rats. Psychopharmacology, 85, 436439.Google Scholar
Tapert, S.F. & Brown, S.A. (2000). Substance dependence, family history of alcohol dependence, and neuropsychological functioning in adolescence. Addiction, 95, 10431053.Google Scholar
Tapert, S.F., Granholm, E., Leedy, N.G., & Brown, S.A. (2002). Substance use and withdrawal: Neuropsychological functioning over 8 years in youth. Journal of the International Neuropsychological Society, 8, 873883.Google Scholar
Tarter, R.E., Vanyukov, M., Kirisci, L., Reynolds, M., & Clark, D.B. (2006). Predictors of marijuana use in adolescents before and after licit drug use: Examination of the gateway hypothesis. American Journal of Psychiatry, 163, 21342140.Google Scholar
Teichner, G., Donohue, B., Crum, T.A., Azrin, N.H., & Golden, C.J. (2000). The relationship of neuropsychological functioning to measures of substance use in an adolescent drug abusing sample. International Journal of Neuroscience, 104, 113124.Google Scholar
Toga, A.W., Thompson, P.M., & Sowell, E.R. (2006). Mapping brain maturation. Trends in Neurosciences, 29, 148159.Google Scholar
Tzilos, G.K., Cintron, C.B., Wood, J.B., Simpson, N.S., Young, A.D., Pope, H.G., & Yurgelun-Todd, D. (2005). Lack of hippocampal volume change in long-term heavy cannabis users. American Journal of Addiction, 14, 6472.Google Scholar
Varma, V.K., Malhotra, A.K., Dang, R., Das, K., & Nehra, R. (1988). Cannabis and cognitive functions: A prospective study. Drug and Alcohol Dependence, 21, 147152.Google Scholar
Verdejo-García, A., López-Torrecillas, F., Giménez, C.O., & Pérrez-García, M. (2004). Clinical implications and methodological challenges in the study of the neuropsychological correlates of cannabis, stimulant, and opioid abuse. Neuropsychology Review, 14, 141.Google Scholar
Wechsler, D. (1997a). Manual for the Wechsler Memory Scale-3rd Edition. New York: Psychological Corporation.
Wechsler, D. (1997b). WAIS-III Manual. New York: Psychological Corporation.
Wechsler, D. (1999). Wechsler Abbreviated Scale of Intelligence. San Antonio, TX: The Psychological Corporation.
Wilkinson, G. (1993). Wide Range Achievement Test, 3rd Edition (WRAT-3) Manual. Wilmington, DE: Wide Range, Inc.
Wilson, W., Mathew, R., Turkington, T., Hawk, T., Coleman, R.E., & Provenzale, J. (2000). Brain morphological changes and early marijuana use: A magnetic resonance and positron emission tomography study. Journal of Addictive Diseases, 19, 122.Google Scholar