Arpana Agrawal1, Julia D Grant2, Michael T Lynskey3, Pamela A F Madden2, Andrew C Heath2, Kathleen K Bucholz2, Carolyn E Sartor4. 1. Washington University School of Medicine, Department of Psychiatry, 660 S. Euclid, CB 8134, Saint Louis, MO 63110, USA. Electronic address: arpana@wustl.edu. 2. Washington University School of Medicine, Department of Psychiatry, 660 S. Euclid, CB 8134, Saint Louis, MO 63110, USA. 3. King's College, Department of Addictions, London, UK. 4. Yale University School of Medicine, Department of Psychiatry, New Haven, CT, USA.
Abstract
BACKGROUND: Use of cigarettes and cannabis frequently co-occurs. We examine the role of genetic and environmental influences on variation in and covariation between tobacco cigarette and cannabis use across European-American (EA) and African-American (AA) women. METHODS: Data on lifetime cannabis and cigarette use were drawn from interviews of 956 AA and 3557 EA young adult female twins and non-twin same sex female full siblings. Twin modeling was used to decompose variance in and covariance between cigarette and cannabis use into additive genetic, shared, special twin and non-shared environmental sources. RESULTS: Cigarette use was more common in EAs (75.3%, 95% C.I. 73.8-76.7%) than AAs (64.2%, 95% C.I. 61.2-67.2%) while cannabis use was marginally more commonly reported by AAs (55.5%, 95% C.I. 52.5-58.8%) than EAs (52.4%, 95% C.I. 50.7-54.0%). Additive genetic factors were responsible for 43-66% of the variance in cigarette and cannabis use. Broad shared environmental factors (shared+special twin) played a more significant role in EA (23-29%) than AA (2-15%) women. In AA women, the influence of non-shared environment was more pronounced (42-45% vs. 11-19% in EA women). There was strong evidence for the same familial influences underlying use of both substances (rA=0.82-0.89; rC+T=0.70-0.75). Non-shared environmental factors were also correlated but less so (rE=0.48-0.66). No racial/ethnic differences were apparent in these sources of covariation. CONCLUSION: Heritability of cigarette and cannabis use is comparable across racial/ethnic groups. Differences in the contribution of shared and non-shared environmental influences indicate that different factors may shape substance use in EA and AA women.
BACKGROUND: Use of cigarettes and cannabis frequently co-occurs. We examine the role of genetic and environmental influences on variation in and covariation between tobacco cigarette and cannabis use across European-American (EA) and African-American (AA) women. METHODS: Data on lifetime cannabis and cigarette use were drawn from interviews of 956 AA and 3557 EA young adult female twins and non-twin same sex female full siblings. Twin modeling was used to decompose variance in and covariance between cigarette and cannabis use into additive genetic, shared, special twin and non-shared environmental sources. RESULTS: Cigarette use was more common in EAs (75.3%, 95% C.I. 73.8-76.7%) than AAs (64.2%, 95% C.I. 61.2-67.2%) while cannabis use was marginally more commonly reported by AAs (55.5%, 95% C.I. 52.5-58.8%) than EAs (52.4%, 95% C.I. 50.7-54.0%). Additive genetic factors were responsible for 43-66% of the variance in cigarette and cannabis use. Broad shared environmental factors (shared+special twin) played a more significant role in EA (23-29%) than AA (2-15%) women. In AA women, the influence of non-shared environment was more pronounced (42-45% vs. 11-19% in EA women). There was strong evidence for the same familial influences underlying use of both substances (rA=0.82-0.89; rC+T=0.70-0.75). Non-shared environmental factors were also correlated but less so (rE=0.48-0.66). No racial/ethnic differences were apparent in these sources of covariation. CONCLUSION: Heritability of cigarette and cannabis use is comparable across racial/ethnic groups. Differences in the contribution of shared and non-shared environmental influences indicate that different factors may shape substance use in EA and AA women.
Authors: Michele L Pergadia; Andrew C Heath; Arpana Agrawal; Kathleen K Bucholz; Nicholas G Martin; Pamela A F Madden Journal: Behav Genet Date: 2006-02-14 Impact factor: 2.805
Authors: Arpana Agrawal; Pamela A F Madden; Kathleen K Bucholz; Andrew C Heath; Michael T Lynskey Journal: Drug Alcohol Depend Date: 2008-03-06 Impact factor: 4.492
Authors: Richard E Bélanger; Christina Akre; Emmanuel Kuntsche; Gerhard Gmel; Joan-Carles Suris Journal: Nicotine Tob Res Date: 2011-03-31 Impact factor: 4.244
Authors: Arpana Agrawal; Judy L Silberg; Michael T Lynskey; Hermine H Maes; Lindon J Eaves Journal: Drug Alcohol Depend Date: 2010-01-04 Impact factor: 4.492