Browsing by Author "Olfson, Emily"

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    An ADH1B variant and peer drinking in progression to adolescent drinking milestones: Evidence of a gene-by-environment interaction
    (Wiley Online Library, 2014-10) Olfson, Emily; Edenberg, Howard J.; Nurnberger Jr., John; Agrawal, Arpana; Bucholz, Kathleen K.; Almasy, Laura A.; Chorlian, David; Dick, Danielle M.; Hesselbrock, Victor M.; Kramer, John R.; Kuperman, Samuel; Porjesz, Bernice; Schuckit, Marc A.; Tischfield, Jay A.; Wang, Jen-Chyong; Wetherill, Leah; Foroud, Tatiana M.; Rice, John; Goate, Alison; Bierut, Laura J.; Department of Biochemistry & Molecular Biology, IU School of Medicine
    BACKGROUND: Adolescent drinking is an important public health concern, one that is influenced by both genetic and environmental factors. The functional variant rs1229984 in alcohol dehydrogenase 1B (ADH1B) has been associated at a genome-wide level with alcohol use disorders in diverse adult populations. However, few data are available regarding whether this variant influences early drinking behaviors and whether social context moderates this effect. This study examines the interplay between rs1229984 and peer drinking in the development of adolescent drinking milestones. METHODS: One thousand five hundred and fifty European and African American individuals who had a full drink of alcohol before age 18 were selected from a longitudinal study of youth as part of the Collaborative Study on the Genetics of Alcoholism (COGA). Cox proportional hazards regression, with G × E product terms in the final models, was used to study 2 primary outcomes during adolescence: age of first intoxication and age of first DSM-5 alcohol use disorder symptom. RESULTS: The minor A allele of rs1229984 was associated with a protective effect for first intoxication (HR = 0.56, 95% CI 0.41 to 0.76) and first DSM-5 symptom (HR = 0.45, 95% CI 0.26 to 0.77) in the final models. Reporting that most or all best friends drink was associated with a hazardous effect for first intoxication (HR = 1.81, 95% CI 1.62 to 2.01) and first DSM-5 symptom (HR = 2.17, 95% 1.88 to 2.50) in the final models. Furthermore, there was a significant G × E interaction for first intoxication (p = 0.002) and first DSM-5 symptom (p = 0.01). Among individuals reporting none or few best friends drinking, the ADH1B variant had a protective effect for adolescent drinking milestones, but for those reporting most or all best friends drinking, this effect was greatly reduced. CONCLUSIONS: Our results suggest that the risk factor of best friends drinking attenuates the protective effect of a well-established ADH1B variant for 2 adolescent drinking behaviors. These findings illustrate the interplay between genetic and environmental factors in the development of drinking milestones during adolescence.
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    CYP2A6 metabolism in the development of smoking behaviors in young adults
    (Wiley, 2018-01) Olfson, Emily; Bloom, Joseph; Bertelsen, Sarah; Budde, John P.; Breslau, Naomi; Brooks, Andrew; Culverhouse, Robert; Chan, Grace; Chen, Li-Shiun; Chorlian, David; Dick, Danielle M.; Edenberg, Howard J.; Hartz, Sarah; Hatsukami, Dorothy; Hesselbrock, Victor M.; Johnson, Eric O.; Kramer, John R.; Kuperman, Samuel; Meyers, Jacquelyn L.; Nurnberger, John; Porjesz, Bernice; Saccone, Nancy L.; Schuckit, Marc A.; Stitzel, Jerry; Tischfield, Jay A.; Rice, John P.; Goate, Alison; Bierut, Laura J.; Biochemistry and Molecular Biology, School of Medicine
    Cytochrome P450 2A6 (CYP2A6) encodes the enzyme responsible for the majority of nicotine metabolism. Previous studies support that slow metabolizers smoke fewer cigarettes once nicotine dependent but provide conflicting results on the role of CYP2A6 in the development of dependence. By focusing on the critical period of young adulthood, this study examines the relationship of CYP2A6 variation and smoking milestones. A total of 1209 European American young adults enrolled in the Collaborative Study on the Genetics of Alcoholism were genotyped for CYP2A6 variants to calculate a previously well-validated metric that estimates nicotine metabolism. This metric was not associated with the transition from never smoking to smoking initiation nor with the transition from initiation to daily smoking (P > 0.4). But among young adults who had become daily smokers (n = 506), decreased metabolism was associated with increased risk of nicotine dependence (P = 0.03) (defined as Fagerström Test for Nicotine Dependence score ≥4). This finding was replicated in the Collaborative Genetic Study of Nicotine Dependence with 335 young adult daily smokers (P = 0.02). Secondary meta-analysis indicated that slow metabolizers had a 53 percent increased odds (OR = 1.53, 95 percent CI 1.11-2.11, P = 0.009) of developing nicotine dependence compared with normal metabolizers. Furthermore, secondary analyses examining four-level response of time to first cigarette after waking (>60, 31-60, 6-30, ≤5 minutes) demonstrated a robust effect of the metabolism metric in Collaborative Study on the Genetics of Alcoholism (P = 0.03) and Collaborative Genetic Study of Nicotine Dependence (P = 0.004), illustrating the important role of this measure of dependence. These findings highlight the complex role of CYP2A6 variation across different developmental stages of smoking behaviors.