Early cannabis use and estimated risk of later onset of depression spells: Epidemiologic evidence from the population-based World Health Organization World Mental Health Survey Initiative.
Early-onset cannabis use is widespread in many countries and might cause later onset of depression. Sound epidemiologic data across countries are missing. The authors estimated the suspected causal association that links early-onset (age <17 years) cannabis use with later-onset (age > or =17 years) risk of a depression spell, using data on 85,088 subjects from 17 countries participating in the population-based World Health Organization World Mental Health Survey Initiative (2001-2005). In all surveys, multistage household probability samples were evaluated with a fully structured diagnostic interview for assessment of psychiatric conditions. The association between early-onset cannabis use and later risk of a depression spell was studied using conditional logistic regression with local area matching of cases and controls, controlling for sex, age, tobacco use, and other mental health problems. The overall association was modest (controlled for sex and age, risk ratio = 1.5, 95% confidence interval: 1.4, 1.7), was statistically robust in 5 countries, and showed no sex difference. The association did not change appreciably with statistical adjustment for mental health problems, except for childhood conduct problems, which reduced the association to nonsignificance. This study did not allow differentiation of levels of cannabis use; this issue deserves consideration in future research.
Department of Epidemiology, Netherlands Institute of Mental Health and Addiction, Utrecht, the Netherlands. rgraaf@trimbos.nl
Ron
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de Graaf
Mirjana
M
Radovanovic
Margriet
M
van Laar
Brian
B
Fairman
Louisa
L
Degenhardt
Sergio
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Aguilar-Gaxiola
Ronny
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Bruffaerts
Giovanni
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de Girolamo
John
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Fayyad
Oye
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Gureje
Josep Maria
JM
Haro
Yueqin
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Huang
Stanislav
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Kostychenko
Jean-Pierre
JP
Lépine
Herbert
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Matschinger
Maria Elena Medina
ME
Mora
Yehuda
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Neumark
Johan
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Ormel
Jose
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Posada-Villa
Dan J
DJ
Stein
Hisateru
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Tachimori
J Elisabeth
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Wells
James C
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Anthony
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002188:Cannabis / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D014943:Global Health; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000150:complications; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D014944:World Health Organization