Skip to main content
    • Aa
    • Aa

Cannabis use at a young age is associated with psychotic experiences

  • C. D. Schubart (a1), W. A. van Gastel (a1), E. J. Breetvelt (a1), S. L. Beetz (a1), R. A. Ophoff (a1) (a2) (a3), I. E. C. Sommer (a1), R. S. Kahn (a1) and M. P. M. Boks (a1) (a4)...

Cannabis use is associated with psychosis and a range of subclinical psychiatric symptoms. The strength of this association depends on dosage and age at first use. The current study investigates whether level of cannabis exposure and starting age are associated with specific profiles of subclinical symptoms.


We collected cross-sectional data from a young adult population sample by administering an online version of the Community Assessment of Psychic Experiences (CAPE). Cannabis exposure was quantified as the amount of Euros spent on cannabis per week and the age of initial cannabis use. The primary outcome measure was the odds ratio (OR) to belong to the highest 10% of scores on the total CAPE and the positive-, negative- and depressive symptom dimensions.


In 17 698 adolescents (mean age 21.6, s.d.=4.2 years), cannabis use at age 12 years or younger was strongly associated with a top 10% score on psychotic experiences [OR 3.1, 95% confidence interval (CI) 2.1–4.3] and to a lesser degree with negative symptoms (OR 1.7, 95% CI 1.1–2.5). The OR of heavy users (>€25/week) for negative symptoms was 3.4 (95% CI 2.9–4.1), for psychotic experiences 3.0 (95% CI 2.4–3.6), and for depressive symptoms 2.8 (95% CI 2.3–3.3).


Early start of cannabis use is strongly associated with subclinical psychotic symptoms and to a lesser degree with negative symptoms, while smoking high amounts of cannabis is associated with increased levels of all three symptom dimensions: psychotic, negative and depressive. These results support the hypothesis that the impact of cannabis use is age specific.

Corresponding author
*Address for correspondence: C. D. Schubart, M.D., University Medical Centre Utrecht, HP. B.01.206, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands. (Email:
Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

L Arseneault , M Cannon , R Poulton , R Murray , A Caspi , TE Moffitt (2002). Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study. British Medical Journal 325, 12121213.

KA Balter , O Balter , E Fondell , YT Lagerros (2005). Web-based and mailed questionnaires: a comparison of response rates and compliance. Epidemiology 16, 577579.

T Buchanan , JL Smith (1999). Using the Internet for psychological research: personality testing on the World Wide Web. British Journal of Psychology 90, 125144.

YM Cha , AM White , CM Kuhn , WA Wilson , HS Swartzwelder (2006). Differential effects of delta9-THC on learning in adolescent and adult rats. Pharmacology, Biochemistry and Behavior 83, 448455.

LJ Chapman , JP Chapman , TR Kwapil , M Eckblad , MC Zinser (1994). Putatively psychosis-prone subjects 10 years later. Journal of Abnormal Psychology 103, 171183.

V Chevaleyre , KA Takahashi , PE Castillo (2006). Endocannabinoid-mediated synaptic plasticity in the CNS. Annual Review of Neuroscience 29, 3776.

ME Coles , LM Cook , TR Blake (2007). Assessing obsessive compulsive symptoms and cognitions on the Internet: evidence for the comparability of paper and Internet administration. Behaviour Research and Therapy 45, 22322240.

P Cuijpers , P Boluijt , A van Straten (2008). Screening of depression in adolescents through the Internet: sensitivity and specificity of two screening questionnaires. European Child and Adolescent Psychiatry 17, 3238.

T Donker , A van Straten , I Marks , P Cuijpers (2009). Brief self-rated screening for depression on the Internet. Journal of Affective Disorders 122, 253259.

A Ekman , PW Dickman , A Klint , E Weiderpass , JE Litton (2006). Feasibility of using web-based questionnaires in large population-based epidemiological studies. European Journal of Epidemiology 21, 103111.

DM Fergusson , LJ Horwood , NR Swain-Campbell (2003). Cannabis dependence and psychotic symptoms in young people. Psychological Medicine 33, 1521.

J Fernandez-Ruiz , F Berrendero , ML Hernandez , JA Ramos (2000). The endogenous cannabinoid system and brain development. Trends in Neurosciences 23, 1420.

L Garcia-Gil , R de Miguel , RM Munoz , M Cebeira , MA Villanua , JA Ramos , JJ Fernandez-Ruiz (1997). Perinatal delta(9)-tetrahydrocannabinol exposure alters the responsiveness of hypothalamic dopaminergic neurons to dopamine-acting drugs in adult rats. Neurotoxicology and Teratology 19, 477487.

L Garcia-Gil , R de Miguel , J Romero , A Perez , JA Ramos , JJ Fernandez-Ruiz (1999). Perinatal delta9-tetrahydrocannabinol exposure augmented the magnitude of motor inhibition caused by GABA(B), but not GABA(A), receptor agonists in adult rats. Neurotoxicology and Teratology 21, 277283.

SD Gosling , S Vazire , S Srivastava , OP John (2004). Should we trust web-based studies? A comparative analysis of six preconceptions about Internet questionnaires. American Psychologist 59, 93–104.

AL Graham , GD Papandonatos (2008). Reliability of Internet- versus telephone-administered questionnaires in a diverse sample of smokers. Journal of Medical Internet Research 10, e8.

AL Graham , GD Papandonatos , BC Bock , NK Cobb , A Baskin-Sommers , R Niaura , DB Abrams (2006). Internet- vs. telephone-administered questionnaires in a randomized trial of smoking cessation. Nicotine and Tobacco Research 8 (Suppl. 1), S49S57.

M Hanssen , M Bak , R Bijl , W Vollebergh , J van Os (2005). The incidence and outcome of subclinical psychotic experiences in the general population. British Journal of Clinical Psychology 44, 181191.

M Hanssen , F Peeters , L Krabbendam , S Radstake , H Verdoux , J van Os (2003). How psychotic are individuals with non-psychotic disorders? Social Psychiatry and Psychiatric Epidemiology 38, 149154.

M Hernandez , F Berrendero , I Suarez , L Garcia-Gil , M Cebeira , K Mackie , JA Ramos , J Fernandez-Ruiz (2000). Cannabinoid CB(1) receptors colocalize with tyrosine hydroxylase in cultured fetal mesencephalic neurons and their activation increases the levels of this enzyme. Brain Research 857, 5665.

L Hides , DI Lubman , J Buckby , HP Yuen , E Cosgrave , K Baker , AR Yung (2009). The association between early cannabis use and psychotic-like experiences in a community adolescent sample. Schizophrenia Research 112, 130135.

TK Houston , LA Cooper , HT Vu , J Kahn , J Toser , DE Ford (2001). Screening the public for depression through the Internet. Psychiatric Services 52, 362367.

A Joinson (1999). Social desirability, anonymity, and Internet-based questionnaires. Behavior Research Methods, Instruments, and Computers 31, 433438.

Y Khazaal , A Chatton , S Cochand , D Zullino (2008). Quality of web-based information on cannabis addiction. Journal of Drug Education 38, 97–107.

M Konings , M Bak , M Hanssen , J van Os , L Krabbendam (2006). Validity and reliability of the CAPE: a self-report instrument for the measurement of psychotic experiences in the general population. Acta Psychiatrica Scandinavica 114, 5561.

M Konings , C Henquet , HD Maharajh , G Hutchinson , J van Os (2008). Early exposure to cannabis and risk for psychosis in young adolescents in Trinidad. Acta Psychiatrica Scandinavica 118, 209213.

DA Lewis (1997). Development of the prefrontal cortex during adolescence: insights into vulnerable neural circuits in schizophrenia. Neuropsychopharmacology 16, 385398.

CC Lin , YM Bai , CY Liu , MC Hsiao , JY Chen , SJ Tsai , WC Ouyang , CH Wu , YC Li (2007). Web-based tools can be used reliably to detect patients with major depressive disorder and subsyndromal depressive symptoms. BMC Psychiatry 7, 12.

J McGrath , J Welham , J Scott , D Varghese , L Degenhardt , MR Hayatbakhsh , R Alati , GM Williams , W Bor , JM Najman (2010). Association between cannabis use and psychosis-related outcomes using sibling pair analysis in a cohort of young adults. Archives of General Psychiatry 67, 440447.

R Mechoulam , Y Gaoni (1965). A total synthesis of dl-delta-1-tetrahydrocannabinol, the active constituent of hashish. Journal of the American Chemical Society 87, 32733275.

P Meyerson , WW Tryon (2003). Validating Internet research: a test of the psychometric equivalence of Internet and in-person samples. Behavior Research Methods, Instruments, and Computers 35, 614620.

J Miettunen , S Tormanen , GK Murray , PB Jones , P Maki , H Ebeling , I Moilanen , A Taanila , M Heinimaa , M Joukamaa , J Veijola (2008). Association of cannabis use with prodromal symptoms of psychosis in adolescence. British Journal of Psychiatry 192, 470471.

F Molina-Holgado , FJ Alvarez , I Gonzalez , MT Antonio , ML Leret (1997). Maternal exposure to delta 9-tetrahydrocannabinol (delta 9-THC) alters indolamine levels and turnover in adult male and female rat brain regions. Brain Research Bulletin 43, 173178.

TH Moore , S Zammit , A Lingford-Hughes , TR Barnes , PB Jones , M Burke , G Lewis (2007). Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review. Lancet 370, 319328.

M O'Shea , ME Singh , IS McGregor , PE Mallet (2004). Chronic cannabinoid exposure produces lasting memory impairment and increased anxiety in adolescent but not adult rats. Journal of Psychopharmacology 18, 502508.

GC Patton , C Coffey , JB Carlin , L Degenhardt , M Lynskey , W Hall (2002). Cannabis use and mental health in young people: cohort study. British Medical Journal 325, 11951198.

R Poulton , A Caspi , TE Moffitt , M Cannon , R Murray , H Harrington (2000). Children's self-reported psychotic symptoms and adult schizophreniform disorder: a 15-year longitudinal study. Archives of General Psychiatry 57, 10531058.

HR Quinn , I Matsumoto , PD Callaghan , LE Long , JC Arnold , N Gunasekaran , MR Thompson , B Dawson , PE Mallet , MA Kashem , H Matsuda-Matsumoto , T Iwazaki , IS McGregor (2008). Adolescent rats find repeated delta(9)-THC less aversive than adult rats but display greater residual cognitive deficits and changes in hippocampal protein expression following exposure. Neuropsychopharmacology 33, 11131126.

LN Robins , J Wing , HU Wittchen , JE Helzer , TF Babor , J Burke , A Farmer , A Jablenski , R Pickens , DA Regier (1988). The Composite International Diagnostic Interview. An epidemiologic instrument suitable for use in conjunction with different diagnostic systems and in different cultures. Archives of General Psychiatry 45, 10691077.

DB Rubin (1987). Multiple Imputation for Nonresponse in Surveys (1st edn). John Wiley & Sons: New York.

M Schneider , M Koch (2003). Chronic pubertal, but not adult chronic cannabinoid treatment impairs sensorimotor gating, recognition memory, and the performance in a progressive ratio task in adult rats. Neuropsychopharmacology 28, 17601769.

V Spek , I Nyklicek , P Cuijpers , V Pop (2008). Internet administration of the Edinburgh Depression Scale. Journal of Affective Disorders 106, 301305.

NC Stefanis , P Delespaul , C Henquet , C Bakoula , CN Stefanis , J van Os (2004). Early adolescent cannabis exposure and positive and negative dimensions of psychosis. Addiction 99, 13331341.

V Trezza , V Cuomo , LJ Vanderschuren (2008). Cannabis and the developing brain: insights from behavior. European Journal of Pharmacology 585, 441452.

MA Vallejo , CM Jordan , MI Diaz , MI Comeche , J Ortega (2007). Psychological assessment via the Internet: a reliability and validity study of online (vs paper-and-pencil) versions of the General Health Questionnaire-28 (GHQ-28) and the Symptoms Check-List-90 – Revised (SCL-90-R). Journal of Medical Internet Research 9, e2.

J van Os , S Kapur (2009). Schizophrenia. Lancet 374, 635645.

H Verdoux , F Sorbara , C Gindre , JD Swendsen , J van Os (2003). Cannabis use and dimensions of psychosis in a nonclinical population of female subjects. Schizophrenia Research 59, 7784.

NJ Wiles , S Zammit , P Bebbington , N Singleton , H Meltzer , G Lewis (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.

AR Yung , B Nelson , K Baker , JA Buckby , G Baksheev , EM Cosgrave (2009). Psychotic-like experiences in a community sample of adolescents: implications for the continuum model of psychosis and prediction of schizophrenia. Australian and New Zealand Journal of Psychiatry 43, 118128.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Psychological Medicine
  • ISSN: 0033-2917
  • EISSN: 1469-8978
  • URL: /core/journals/psychological-medicine
Please enter your name
Please enter a valid email address
Who would you like to send this to? *