Cannabis use and psychosis: a longitudinal population-based study.

Cannabis use may increase the risk of psychotic disorders and result in a poor prognosis for those with an established vulnerability to psychosis. A 3-year follow-up (1997-1999) is reported of a general population of 4,045 psychosis-free persons and of 59 subjects in the Netherlands with a baseline diagnosis of psychotic disorder. Substance use was assessed at baseline, 1-year follow-up, and 3-year follow-up. Baseline cannabis use predicted the presence at follow-up of any level of psychotic symptoms (adjusted odds ratio (OR) = 2.76, 95% confidence interval (CI): 1.18, 6.47), as well as a severe level of psychotic symptoms (OR = 24.17, 95% CI: 5.44, 107.46), and clinician assessment of the need for care for psychotic symptoms (OR = 12.01, 95% CI: 2.24, 64.34). The effect of baseline cannabis use was stronger than the effect at 1-year and 3-year follow-up, and more than 50% of the psychosis diagnoses could be attributed to cannabis use. On the additive scale, the effect of cannabis use was much stronger in those with a baseline diagnosis of psychotic disorder (risk difference, 54.7%) than in those without (risk difference, 2.2%; p for interaction = 0.001). Results confirm previous suggestions that cannabis use increases the risk of both the incidence of psychosis in psychosis-free persons and a poor prognosis for those with an established vulnerability to psychotic disorder.

[1]  P. Allebeck,et al.  CANNABIS AND SCHIZOPHRENIA , 1988, The Lancet.

[2]  R. Smart,et al.  Drug use and drinking among students in 36 countries. , 2000, Addictive behaviors.

[3]  G. Thornicroft.  Cannabis and Psychosis , 1990, British Journal of Psychiatry.

[4]  R. Spitzer,et al.  Diagnosis and need for treatment are not the same. , 1998, Archives of general psychiatry.

[5]  J. Os,et al.  Prevalence of psychotic disorder and community level of psychotic symptoms: an urban-rural comparison. , 2001, Archives of general psychiatry.

[6]  P. Dingemans,et al.  Cannabis abuse and the course of recent onset schizophrenic disorders , 1993, Schizophrenia Research.

[7]  A. B. Hill.  The Environment and Disease: Association or Causation? , 1965, Proceedings of the Royal Society of Medicine.

[8]  B. Dean,et al.  Studies on [3H]CP-55940 binding in the human central nervous system: regional specific changes in density of cannabinoid-1 receptors associated with schizophrenia and cannabis use , 2001, Neuroscience.

[9]  M. Martinez-Arevalo,et al.  Cannabis Consumption as a Prognostic Factor in Schizophrenia , 1994, British Journal of Psychiatry.

[10]  J Darroch,et al.  Biologic synergism and parallelism. , 1997, American journal of epidemiology.

[11]  D S Rae,et al.  Comorbidity of mental disorders with alcohol and other drug abuse. Results from the Epidemiologic Catchment Area (ECA) Study. , 1990, JAMA.

[12]  Andrew Johns,et al.  Psychiatric effects of cannabis , 2001, British Journal of Psychiatry.

[13]  H. Emrich,et al.  Elevated endogenous cannabinoids in schizophrenia. , 1999, Neuroreport.

[14]  M. Höfler,et al.  Patterns of cannabis use, abuse and dependence over time: incidence, progression and stability in a sample of 1228 adolescents. , 1999, Addiction.

[15]  P. Kelly,et al.  Alcohol and drug use in UK university students , 1996, The Lancet.

[16]  F. Smit,et al.  Psychiatric and sociodemographic predictors of attrition in a longitudinal study: The Netherlands Mental Health Survey and Incidence Study (NEMESIS). , 2000, American journal of epidemiology.

[17]  A. Farmer,et al.  A comparison of clinical and diagnostic interview schedule diagnoses. Physician reexamination of lay-interviewed cases in the general population. , 1985, Archives of general psychiatry.

[18]  E. Bromet,et al.  Substance use disorder and the early course of illness in schizophrenia and affective psychosis. , 1997, Schizophrenia bulletin.

[19]  W. Eaton,et al.  A comparison of self-report and clinical diagnostic interviews for depression: diagnostic interview schedule and schedules for clinical assessment in neuropsychiatry in the Baltimore epidemiologic catchment area follow-up. , 2000, Archives of general psychiatry.

[20]  J. Os,et al.  The ecogenetics of schizophrenia: a review , 1998, Schizophrenia Research.

[21]  M. First,et al.  The Structured Clinical Interview for DSM-III-R (SCID). I: History, rationale, and description. , 1992, Archives of general psychiatry.

[22]  H. Wittchen,et al.  Composite International Diagnostic Interview. CIDI Interviewerheft (deutsche Bearbeitung) , 1991 .

[23]  R. Bijl,et al.  The Netherlands Mental Health Survey and Incidence Study (NEMESIS): objectives and design , 1998, Social Psychiatry and Psychiatric Epidemiology.

[24]  R. Bijl,et al.  Prevalence of psychiatric disorder in the general population: results of the Netherlands Mental Health Survey and Incidence Study (NEMESIS) , 1998, Social Psychiatry and Psychiatric Epidemiology.

[25]  Sven Andréasson,et al.  CANNABIS AND SCHIZOPHRENIA A Longitudinal Study of Swedish Conscripts , 1987, The Lancet.

[26]  Jim van Os,et al.  Strauss (1969) revisited: a psychosis continuum in the general population? , 2000, Schizophrenia Research.

[27]  R. Murray,et al.  Morbid risk of schizophrenia for relatives of patients with cannabis-associated psychosis , 1995, Schizophrenia Research.

[28]  L. Degenhardt,et al.  The association between psychosis and problematical drug use among Australian adults: findings from the National Survey of Mental Health and Well-Being , 2001, Psychological Medicine.

[29]  S. Cooper,et al.  RELAPSE OF DEPRESSION IN PEOPLE WITH DOWN'S SYNDROME , 1994 .

[30]  J. Os,et al.  Suicidality and substance misuse in first‐admitted subjects with psychotic disorder , 1999, Acta psychiatrica Scandinavica.

[31]  M. Folstein,et al.  Comparison of the lay Diagnostic Interview Schedule and a standardized psychiatric diagnosis. Experience in eastern Baltimore. , 1985, Archives of general psychiatry.

[32]  H. Häfner,et al.  Substance abuse and the onset of schizophrenia , 1996, Biological Psychiatry.

[33]  T. Palomo,et al.  Chronic (-)-delta9-tetrahydrocannabinol treatment induces sensitization to the psychomotor effects of amphetamine in rats. , 1999, European journal of pharmacology.

[34]  J. Overall,et al.  The Brief Psychiatric Rating Scale , 1962 .

[35]  Tx Station.  Stata Statistical Software: Release 7. , 2001 .

[36]  G. Thornicroft,et al.  The Camberwell Assessment of Need (CAN): comparison of assessments by staff and patients of the needs of the severely mentally ill , 1996, Social Psychiatry and Psychiatric Epidemiology.

[37]  R. Kessler,et al.  Lifetime co-occurrence of DSM-III-R alcohol abuse and dependence with other psychiatric disorders in the National Comorbidity Survey. , 1997, Archives of general psychiatry.

[38]  D. Clayton,et al.  Statistical Models in Epidemiology , 1993 .

[39]  M Susser,et al.  What is a cause and how do we know one? A grammar for pragmatic epidemiology. , 1991, American journal of epidemiology.

[40]  G. Di Chiara,et al.  Cannabinoid and heroin activation of mesolimbic dopamine transmission by a common mu1 opioid receptor mechanism. , 1997, Science.