OBJECTIVE: Adolescents who regularly use marijuana may be at heightened risk of developing subclinical and clinical psychotic symptoms. However, this association could be explained by reverse causation or other factors. To address these limitations, the current study examined whether adolescents who engage in regular marijuana use exhibit a systematic increase in subclinical psychotic symptoms that persists during periods of sustained abstinence. METHOD: The sample comprised 1,009 boys who were recruited in 1st and 7th grades. Self-reported frequency of marijuana use, subclinical psychotic symptoms, and several time-varying confounds (e.g., other substance use, internalizing/externalizing problems) were recorded annually from age 13 to 18. Fixed-effects (within-individual change) models examined whether adolescents exhibited an increase in their subclinical psychotic symptoms as a function of their recent and/or cumulative history of regular marijuana use and whether these effects were sustained following abstinence. Models controlled for all time-stable factors (default) and several time-varying covariates as potential confounds. RESULTS: For each year adolescent boys engaged in regular marijuana use, their expected level of subsequent subclinical psychotic symptoms rose by 21% and their expected odds of experiencing subsequent subclinical paranoia or hallucinations rose by 133% and 92%, respectively. The effect of prior regular marijuana use on subsequent subclinical psychotic symptoms persisted even when adolescents stopped using marijuana for a year. These effects were after controlling for all time-stable and several time-varying confounds. No support was found for reverse causation. CONCLUSIONS: These results suggest that regular marijuana use may significantly increase the risk that an adolescent will experience persistent subclinical psychotic symptoms.
OBJECTIVE: Adolescents who regularly use marijuana may be at heightened risk of developing subclinical and clinical psychotic symptoms. However, this association could be explained by reverse causation or other factors. To address these limitations, the current study examined whether adolescents who engage in regular marijuana use exhibit a systematic increase in subclinical psychotic symptoms that persists during periods of sustained abstinence. METHOD: The sample comprised 1,009 boys who were recruited in 1st and 7th grades. Self-reported frequency of marijuana use, subclinical psychotic symptoms, and several time-varying confounds (e.g., other substance use, internalizing/externalizing problems) were recorded annually from age 13 to 18. Fixed-effects (within-individual change) models examined whether adolescents exhibited an increase in their subclinical psychotic symptoms as a function of their recent and/or cumulative history of regular marijuana use and whether these effects were sustained following abstinence. Models controlled for all time-stable factors (default) and several time-varying covariates as potential confounds. RESULTS: For each year adolescent boys engaged in regular marijuana use, their expected level of subsequent subclinical psychotic symptoms rose by 21% and their expected odds of experiencing subsequent subclinical paranoia or hallucinations rose by 133% and 92%, respectively. The effect of prior regular marijuana use on subsequent subclinical psychotic symptoms persisted even when adolescents stopped using marijuana for a year. These effects were after controlling for all time-stable and several time-varying confounds. No support was found for reverse causation. CONCLUSIONS: These results suggest that regular marijuana use may significantly increase the risk that an adolescent will experience persistent subclinical psychotic symptoms.
Authors: Madeline H Meier; Avshalom Caspi; Antony Ambler; HonaLee Harrington; Renate Houts; Richard S E Keefe; Kay McDonald; Aimee Ward; Richie Poulton; Terrie E Moffitt Journal: Proc Natl Acad Sci U S A Date: 2012-08-27 Impact factor: 11.205
Authors: Theresa H M Moore; Stanley Zammit; Anne Lingford-Hughes; Thomas R E Barnes; Peter B Jones; Margaret Burke; Glyn Lewis Journal: Lancet Date: 2007-07-28 Impact factor: 79.321
Authors: Benedetto Vitiello; Guillermo Perez Algorta; L Eugene Arnold; Andrea L Howard; Annamarie Stehli; Brooke S G Molina Journal: J Am Acad Child Adolesc Psychiatry Date: 2017-02-04 Impact factor: 8.829
Authors: Louisa Degenhardt; Sukanta Saha; Carmen C W Lim; Sergio Aguilar-Gaxiola; Ali Al-Hamzawi; Jordi Alonso; Laura H Andrade; Evelyn J Bromet; Ronny Bruffaerts; José Miguel Caldas-de-Almeida; Giovanni de Girolamo; Silvia Florescu; Oye Gureje; Josep M Haro; Elie G Karam; Georges Karam; Viviane Kovess-Masfety; Sing Lee; Jean-Pierre Lepine; Victor Makanjuola; Maria E Medina-Mora; Zeina Mneimneh; Fernando Navarro-Mateu; Marina Piazza; José Posada-Villa; Nancy A Sampson; Kate M Scott; Juan Carlos Stagnaro; Margreet Ten Have; Kenneth S Kendler; Ronald C Kessler; John J McGrath Journal: Addiction Date: 2018-02-21 Impact factor: 6.526
Authors: Nicole R Karcher; Deanna M Barch; Catherine H Demers; David A A Baranger; Andrew C Heath; Michael T Lynskey; Arpana Agrawal Journal: JAMA Psychiatry Date: 2019-01-01 Impact factor: 21.596