BACKGROUND: The associations between age of onset of cannabis use and educational achievement were examined using data from three Australasian cohort studies involving over 6000 participants. The research aims were to compare findings across studies and obtain pooled estimates of association using meta-analytic methods. METHODS: Data on age of onset of cannabis use (<15, 15-17, never before age 18) and three educational outcomes (high school completion, university enrolment, degree attainment) were common to all studies. Each study also assessed a broad range of confounding factors. RESULTS: There were significant (p<.001) associations between age of onset of cannabis use and all outcomes such that rates of attainment were highest for those who had not used cannabis by age 18 and lowest for those who first used cannabis before age 15. These findings were evident for each study and for the pooled data, and persisted after control for confounding. There was no consistent trend for cannabis use to have greater effect on the academic achievement of males but there was a significant gender by age of onset interaction for university enrolment. This interaction suggested that cannabis use by males had a greater detrimental effect on university participation than for females. Pooled estimates suggested that early use of cannabis may contribute up to 17% of the rate of failure to obtain the educational milestones of high school completion, university enrolment and degree attainment. CONCLUSIONS: Findings suggest the presence of a robust association between age of onset of cannabis use and subsequent educational achievement. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.
BACKGROUND: The associations between age of onset of cannabis use and educational achievement were examined using data from three Australasian cohort studies involving over 6000 participants. The research aims were to compare findings across studies and obtain pooled estimates of association using meta-analytic methods. METHODS: Data on age of onset of cannabis use (<15, 15-17, never before age 18) and three educational outcomes (high school completion, university enrolment, degree attainment) were common to all studies. Each study also assessed a broad range of confounding factors. RESULTS: There were significant (p<.001) associations between age of onset of cannabis use and all outcomes such that rates of attainment were highest for those who had not used cannabis by age 18 and lowest for those who first used cannabis before age 15. These findings were evident for each study and for the pooled data, and persisted after control for confounding. There was no consistent trend for cannabis use to have greater effect on the academic achievement of males but there was a significant gender by age of onset interaction for university enrolment. This interaction suggested that cannabis use by males had a greater detrimental effect on university participation than for females. Pooled estimates suggested that early use of cannabis may contribute up to 17% of the rate of failure to obtain the educational milestones of high school completion, university enrolment and degree attainment. CONCLUSIONS: Findings suggest the presence of a robust association between age of onset of cannabis use and subsequent educational achievement. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.
Authors: Mason M Silveira; Jonathon C Arnold; Steven R Laviolette; Cecilia J Hillard; Marta Celorrio; María S Aymerich; Wendy K Adams Journal: Neurosci Biobehav Rev Date: 2016-09-14 Impact factor: 8.989
Authors: William E Copeland; Carol E Adair; Paul Smetanin; David Stiff; Carla Briante; Ian Colman; David Fergusson; John Horwood; Richie Poulton; E Jane Costello; Adrian Angold Journal: J Child Psychol Psychiatry Date: 2013-03-02 Impact factor: 8.982