Author(s): Lynskey MT, Heath AC, Bucholz KK, Slutske WS, Madden PA, et al.
Context Previous studies have reported that early initiation of cannabis (marijuana) use is a significant risk factor for other drug use and drug-related problems. Objective To examine whether the association between early cannabis use and subsequent progression to use of other drugs and drug abuse/dependence persists after controlling for genetic and shared environmental influences. Design Cross-sectional survey conducted in 1996-2000 among an Australian national volunteer sample of 311 young adult (median age, 30 years) monozygotic and dizygotic same-sex twin pairs discordant for early cannabis use (before age 17 years). Main Outcome Measures Self-reported subsequent nonmedical use of prescription sedatives, hallucinogens, cocaine/other stimulants, and opioids; abuse or dependence on these drugs (including cannabis abuse/dependence); and alcohol dependence. Results Individuals who used cannabis by age 17 years had odds of other drug use, alcohol dependence, and drug abuse/dependence that were 2.1 to 5.2 times higher than those of their co-twin, who did not use cannabis before age 17 years. Controlling for known risk factors (early-onset alcohol or tobacco use, parental conflict/ separation, childhood sexual abuse, conduct disorder, major depression, and social anxiety) had only negligible effects on these results. These associations did not differ significantly between monozygotic and dizygotic twins. Conclusions Associations between early cannabis use and later drug use and abuse/ dependence cannot solely be explained by common predisposing genetic or shared environmental factors. The association may arise from the effects of the peer and social context within which cannabis is used and obtained. In particular, early access to and use of cannabis may reduce perceived barriers against the use of other illegal drugs and provide access to these drugs.
Referred From: https://jamanetwork.com/journals/jama/fullarticle/195839
Author(s): Mudasir M
Author(s): Tahira S, Bilal B, Nuarat, Farooz W
Author(s): Braida D, Liminta V, Malabarba L, Zani A, Sala M
Author(s): Witkin JM, Tzavara ET, Nomikos GG
Author(s): James A, James C, Thwaites T
Author(s): Hall W, Degenhardt L
Author(s): Kumra S, Robinson P, Tambyraja R, Jensen D, Schimunek C, et al.
Author(s): Di Forti M, Sallis H, Allegri F, Trotta A, Ferraro L, et al.
Author(s): Di Forti M, Marconi A, Carra E, Fraietta S, Trotta A, et al.
Author(s): Myles H, Myles N, Large M
Author(s): Gabrilla G
Author(s): Martinotti G, Di Iorio G, Tedeschi D, De Berardis D, Niolu C, et al.
Author(s): Agosti V, Nunes E, Levin F
Author(s): Goldstein S
Author(s): Grov C, Kelly BC, Parsons JT
Author(s): Swift W, Hall W, Teesson M
Author(s): Degenhardt L, Hall W
Author(s): Manrique-Garcia E, Zammit S, Dalman C, Hemmingsson T, Allebeck P
Author(s): Grant JD, Lynskey MT, Scherrer JF, Agrawal A, Heath AC, et al.
Author(s): Lynskey MT, Vink JM, Boomsma DI
Author(s): Moore THN, Zammit S, Lingford-Hughes A, Barnes TRE, Jones PB
Author(s): McGrath J, Welham J, Scott J, Varghese D, Degenhardt L, et al.
Author(s): Giordano GN, Ohlsson H, Sundquist K, Sunquist J, Kendler K
Author(s): Power RA, Verweij KJH, Zuhair M, Montgomery GW, Henders AK, et al.
Author(s): Borges G, Bagge CL, Orozco R
Author(s): Wittchen H, Frohlich C, Behrendt S
Author(s): Smith MJ, Barch DM, Wolf TJ, Mamah D, Csernansky JG
Author(s): Lev-Ran S, Roerecke M, Le Foll B, George TP, McKenzie K, et al.
Author(s): Pacek LR, Martins SS, Crum RM
Author(s): Pedersen W
Author(s): Durdle H, Lundahl LH, Johanson CE, Tancer M
Author(s): Bottorff JL1, Johnson JL, Moffat BM, Mulvogue T
Author(s): Nail RL, Gunderson EK, Kolb D
Author(s): Ledoux S, Miller P, Choquet M, Plant M
Author(s): Van den Bree, Marianne BM, Wallace BP
Author(s): Kalant H
Author(s): Georgiades K, Boyle MH
Author(s): Dorard G, Berthoz S, Phan O, Corcos M, Bungener C
Author(s): Field T, Diego M, Sanders C
Author(s): Fleming CB, Mason WA, Mazza JJ, Abbott RD, Catalano RF
Author(s): Barnwell SS, Earleywine M, Wilcox R
Author(s): Baethge C, Hennen J, Khalsa HM, Salvatore P, Tohen M, et al.
Author(s): Volkow ND, Baler RD, Compton WM, Weiss SR