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Cannabis use and psychosis: the origins and implications of an association

  • John Macleod

Abstract

Evidence for the effectiveness of treatment or secondary prevention of psychotic illness such as schizophrenia is often disappointing. This situation reflects our limited understanding of the aetiology of psychosis. There is good evidence that both genetic and environmental factors are implicated but the precise identity of these is unclear. Cannabis use is one candidate as a possible, modifiable environmental influence on both incidence and prognosis of psychosis. Evidence supporting this candidature is exclusively observational, and its strength has perhaps been overestimated and problems related to its interpretation underestimated by some. Nevertheless the possibility that cannabis does cause psychosis remains. Because of this, and because there are other good public health reasons to prevent cannabis use, interventions targeting use need to be evaluated. This evaluation, along with other imaginative approaches to future research, is needed to further our understanding of the determinants of mental illness and how we can most effectively improve the population's mental health.

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References

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Advisory Council on the Misuse of Drugs (2006) Pathways to Problems. Home Office.
Ames, B. N. & Gold, L. S. (1997) The causes and prevention of cancer: gaining perspective. Environmental Health Perspectives, 105 (suppl. 4), 865873.
Amos, A., Wiltshire, S., Bostock, Y. et al (2004) ‘You can't go without a fag … you need it for your hash’: a qualitative exploration of smoking, cannabis and young people. Addiction, 99, 7781.
Andreasson, S., Allebeck, P., Engstrom, A. et al (1987) Cannabis and schizophrenia. A longitudinal study of Swedish conscripts. Lancet, ii, 14831486.
Anthony, J. C., Neumark, Y. D. & Van Etten, M. L. (2000) Do I do what I say? A perspective on self-report methods in drug dependence epidemiology. In The Science of Self-report: Implications for Research and Practice (eds Stone, A. A., Turkkan, J. S., Bachrach, C. A. et al), pp. 175198. Lawrence Erlbaum.
Arseneault, L., Cannon, M., Poulton, R. et al (2002) Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study. BMJ, 325, 12121213.
Arseneault, L., Cannon, M., Witton, J. et al (2004) Causal association between cannabis and psychosis: examination of the evidence. British Journal of Psychiatry, 184, 110117.
Aveyard, P., Cheng, K. K., Almond, J. et al (1999) Cluster randomised controlled trial of expert system based on the transtheoretical (‘stages of change’) model for smoking prevention and cessation in schools. BMJ, 319, 948953.
Beckman, J. A. & Creager, M. A. (2006) The nonlipid effects of statins on endothelial function. Trends in Cardiovascular Medicine, 16, 156162.
Bellosta, S., Ferri, N., Bernini, F. et al (2000) Non-lipid-related effects of statins. Annals of Medicine, 32, 164176.
Carpenter, W. (2003) Foreword. In The Epidemiology of Schizophrenia (eds Murray, R. M., Jones, P. B., Susser, E. et al), pp xvxvi. Cambridge University Press.
Colon, H. M., Robles, R. R. & Sahai, H. (2001) The validity of drug use responses in a household survey in Puerto Rico: comparison of survey responses of cocaine and heroin use with hair tests. International Journal of Epidemiology, 30, 10421049.
Comings, D. E., Muhleman, D. & Gade, R. (1997) Cannabinoid receptor gene (CNR1): association with i.v. drug use. Molecular Psychiatry, 2, 161168.
Davey Smith, G. & Ebrahim, S. (2002) Data dredging, bias or confounding. BMJ, 325, 14371438.
Davey Smith, G. & Ebrahim, S. (2003) ‘Mendelian randomisation’: can genetic epidemiology contribute to understanding environmental determinants of disease? International Journal of Epidemiology, 32, 122.
Davey Smith, G. & Phillips, A. (1990) Declaring independence: why we should be cautious. Journal of Epidemiology and Community Health, 44, 257258.
Davey Smith, G. & Phillips, A. N. (1992) Confounding in epidemiological studies: why ‘independent’ effects may not be all they seem. BMJ, 305, 757759.
Davey Smith, G. & Phillips, A. (2001) Re: ‘cigarette smoking and suicide: a prospective study of 300,000 male active-duty army soldiers’. American Journal of Epidemiology, 153, 307308.
Davey Smith, G., Phillips, A. N. & Neaton, J. D. (1992) Smoking as ‘independent’ risk factor for suicide: illustration of an artifact from observational epidemiology? Lancet, 340, 709712.
Degenhardt, L. & Hall, W. (2006) Is cannabis use a contributory cause of psychosis? Canadian Journal of Psychiatry, 51, 556565.
Degenhardt, L., Hall, W. & Lynskey, M. (2003) Testing hypotheses about the relationship between cannabis use and psychosis. Drug and Alcohol Dependence, 71, 3748.
Egger, M., Schneider, M. & Davey Smith, G. (1998) Spurious precision? Meta-analysis of observational studies. BMJ, 316, 140144.
Fergusson, D. M., Horwood, L. J. & Swain-Campbell, N. R. (2003) Cannabis dependence and psychotic symptoms in young people. Psychological Medicine, 33, 1521.
Gadzicki, D., Muller-Vahl, K. & Stuhrmann, M. (1999) A frequent polymorphism in the coding exon of the human cannabinoid receptor (CNR1) gene. Molecular and Cellular Probes, 13, 321323.
Gray, J. A. M. (2001) Evidence-Based Health Care (2nd edn) Churchill Livingstone.
Gregg, L., Barrowclough, C. & Haddock, G. (2007) Reasons for increased substance use in psychosis. Clinical Psychology Review, 27, 494510. doi: 10.1016/j.cpr.2006.09.004.
Hall, W. & Solowij, N. (1998) Adverse effects of cannabis. Lancet, 352, 16111616.
Henquet, C., Krabbendam, L., Spauwen, J. et al (2005) Prospective cohort study of cannabis use, predisposition for psychosis, and psychotic symptoms in young people. BMJ, 330, 1114.
Hickman, M., Vickerman, P., Macleod, J. et al (2007) Cannabis and schizophrenia: model projections of the impact of the rise in cannabis use on historical and future trends in schizophrenia in England and Wales. Addiction, 102, 597606.
Hill, A. B. (1965) The environment and disease: association or causation? Proceedings of the Royal Society of Medicine, 58, 293300.
Hulley, S., Grady, D., Bush, T. et al (1998) Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. JAMA, 280, 605613.
Kendler, K. S., Jacobson, K. C., Prescott, C. A. et al (2003) Specificity of genetic and environmental risk factors for use and abuse/dependence of cannabis, cocaine, hallucinogens, sedatives, stimulants, and opiates in male twins. American Journal of Psychiatry, 160, 687695.
Last, J. M. (ed.) (1988) A Dictionary of Epidemiology. Oxford University Press.
Little, J. & Khoury, M. J. (2003) Mendelian randomisation: a new spin or real progress? Lancet, 362, 930931.
Macleod, J. (2007) Cannabis use and symptom experience amongst people with mental illness: a commentary on Degenhardt et al Psychological Medicine, 22, 14.
Macleod, J., Davey Smith, G., Heslop, P. et al (2002) Psychological stress and cardiovascular disease: empirical demonstration of bias in a prospective observational study of Scottish men. BMJ, 324, 12471251.
Macleod, J., Oakes, R., Copello, A. et al (2004) Psychological and social sequelae of cannabis and other illicit drug use by young people: a systematic review of longitudinal, general population studies. Lancet, 363, 15791588.
Macleod, J., Oakes, R., Oppenkowski, T. et al (2004b) How strong is the evidence that illicit drug use by young people is an important cause of psychological or social harm? Methodological and policy implications of a systematic review of longitudinal, general population studies. Drugs Education, Policy and Practice, 11, 281297.
Macleod, J., Hickman, M. & Davey Smith, G. (2005) Reporting bias and self-reported drug use. Addiction, 100, 562563.
Maddock, C. & Babbs, M. (2006) Interventions for cannabis misuse. Advances in Psychiatric Treatment, 12, 432439.
Maes, H. H., Sullivan, P. F., Bulik, C. M. et al (2004) A twin study of genetic and environmental influences on tobacco initiation, regular tobacco use and nicotine dependence. Psychological Medicine, 34, 12511261.
Mäki, P., Veijola, J., Jones, P. B. et al (2005) Predictors of schizophrenia – a review. British Medical Bulletin, 73–74, 115.
Maughan, B. & McCarthy, G. (1997) Childhood adversities and psychosocial disorders. British Medical Bulletin, 53, 156169.
May, T., Duffy, M., Warburton, H. et al (2007) Policing Cannabis as a Class C Drug: An Arresting Change? Joseph Rowntree Foundation.
McGrath, J. J. & Saha, S. (2007) Thought experiments on the incidence and prevalence of schizophrenia ‘under the influence’ of cannabis. Addiction, 102, 514515.
Miller, M., Hemenway, D., Bell, N. S. et al (2000) Cigarette smoking and suicide: a prospective study of 300,000 male active-duty Army soldiers. American Journal of Epidemiology, 151, 10601063.
Negrete, J. C. (1988) What's happened to the cannabis debate? British Journal of Addiction, 83, 359372.
Nestler, E. J. & Landsman, D. (2001) Learning about addiction from the genome. Nature, 409, 834835.
Parascandola, M. & Weed, D. L. (2001) Causation in epidemiology. Journal of Epidemiology and Community Health, 55, 905912.
Patton, G. C., Coffey, C., Carlin, J. B. et al (2005) Reverse gateways? Frequent cannabis use as a predictor of tobacco initiation and nicotine dependence. Addiction, 100, 15181525.
Petitti, D. (2004) Commentary: Hormone replacement therapy and coronary heart disease: four lessons. International Journal of Epidemiology, 33, 461463.
Phillips, A. N. & Davey Smith, G. (1991) How independent are ‘independent’ effects? Relative risk estimation when correlated exposures are measured imprecisely. Journal of Clinical Epidemiology, 44, 12231231.
Rhee, S. H., Hewitt, J. K., Young, S. E. et al (2003) Genetic and environmental influences on substance initiation, use, and problem use in adolescents. Archives of General Psychiatry, 60, 12561264.
Rothman, K. J. (1976) Causes. American Journal of Epidemiology, 104, 587592.
Semple, D. M., McIntosh, A. M. & Lawrie, S. M. (2005) Cannabis as a risk factor for psychosis: systematic review. Journal of Psychopharmacology, 19, 187194.
Single, E. (1989) The impact of marijuana decriminalization. Journal of Public Health Policy, 10, 456466.
Sipe, J. C., Chiang, K., Gerber, A. L. et al (2002) A missense mutation in human fatty acid amide hydrolase associated with problem drug use. Proceedings of the National Academy of Sciences, 99, 83948399.
Smit, F., Bolier, L. & Cuijpers, P. (2004) Cannabis use and the risk of later schizophrenia: a review. Addiction, 99, 425430.
Stampfer, M. J. & Colditz, G. A. (1991) Estrogen replacement therapy and coronary heart disease: a quantitative assessment of the epidemiologic evidence. Preventive Medicine, 20, 4763.
Strang, J., Witton, J. & Hall, W. (2000) Improving the quality of the cannabis debate: defining the different domains. BMJ, 320, 108110.
Susser, M. (1991) What is a cause and how do we know one? A grammar for pragmatic epidemiology. American Journal of Epidemiology, 133, 635648.
Taylor, D. R., Fergusson, D. M., Milne, B. J. et al (2002) A longitudinal study of the effects of tobacco and cannabis exposure on lung function in young adults. Addiction, 97, 10551061.
Tien, A. Y. & Anthony, J. C. (1990) Epidemiological analysis of alcohol and drug use as risk factors for psychotic experiences. Journal of Nervous and Mental Disease, 178, 473480.
van Os, J., Bak, M., Hanssen, M. et al (2002) Cannabis use and psychosis: a longitudinal population-based study. American Journal of Epidemiology, 156, 319327.
White, D. & Pitts, M. (1998) Educating young people about drugs: a systematic review. Addiction, 93, 14751487.
Wiles, N. J., Zammit, S., Bebbington, P. et al (2006) Self-reported psychotic symptoms in the general population. Results from the longitudinal study of the British National Psychiatric Morbidity Survey. British Journal of Psychiatry, 188, 519526.
Writing Group for the Women's Health Initiative Investigators (2002) Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women's Health Initiative randomized controlled trial. JAMA, 288, 321333.
Wodak, A., Reinerman, C., Cohen, P. D. A. et al (2002) Cannabis control: costs outweigh the benefits. For and Against. BMJ, 324, 105108.
Wolff, K., Farrell, M., Marsden, J. et al (1999) A review of biological indicators of illicit drug use: practical considerations and clinical usefulness. Addiction, 94, 12791298.
Zammit, S., Allebeck, P., Andreasson, S. et al (2002) Self reported cannabis use as a risk factor for schizophrenia in Swedish conscripts of 1969: historical cohort study. BMJ, 325, 11991201.

Cannabis use and psychosis: the origins and implications of an association

  • John Macleod

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Cannabis use and psychosis: the origins and implications of an association

  • John Macleod
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