Excessive alcohol consumption is one of the leading causes of preventable death in the United States. Approximately 14% of those who use alcohol meet criteria during their lifetime for alcohol dependence, which is characterized by tolerance, withdrawal, inability to stop drinking, and continued drinking despite serious psychological or physiological problems. We explored genetic influences on alcohol dependence among 1,897 European-American and African-American subjects with alcohol dependence compared with 1,932 unrelated, alcohol-exposed, nondependent controls. Constitutional DNA of each subject was genotyped using the Illumina 1M beadchip. Fifteen SNPs yielded P < 10 −5 , but in two independent replication series, no SNP passed a replication threshold of P < 0.05. Candidate gene GABRA2 , which encodes the GABA receptor α2 subunit, was evaluated independently. Five SNPs at GABRA2 yielded nominal (uncorrected) P < 0.05, with odds ratios between 1.11 and 1.16. Further dissection of the alcoholism phenotype, to disentangle the influence of comorbid substance-use disorders, will be a next step in identifying genetic variants associated with alcohol dependence.

Purpose-We sought to examine the sentiment and themes of marijuana-related chatter on Twitter sent by influential Twitter users, and to describe the demographics of these Twitter users.Methods-We assessed the sentiment and themes of a random sample (n=7000) of influential marijuana-related Tweets (sent from 2/5 -3/5/2014). Demographics of the users Tweeting about marijuana were inferred using a social media analytics company (DemographicsPro for Twitter).Results-Most marijuana-related tweets reflected a positive sentiment towards marijuana use, with pro-marijuana Tweets outnumbering anti-marijuana Tweets by a factor of over 15. The most common theme of pro-marijuana Tweets included the Tweeter stating that he/she wants/plans to use marijuana, followed by Tweeting about frequent/heavy/or regular marijuana use and stating that marijuana has health benefits and/or should be legalized. Tweeters of marijuana-related content were younger and a greater proportion was African American compared to the Twitter average. Conclusions-MarijuanaTwitter chatter sent by influential Twitter users tends to be promarijuana and popular among African Americans and youth/young adults. Marijuana-related harms may afflict some individuals; therefore, our findings should be used to inform online and offline prevention efforts that work to target individuals who are most at-risk for harms associated with marijuana use. KeywordsMarijuana; Social Media; Youth © 2014 Society of Adolescent Health and Medicine. All rights reserved.Please address correspondence and reprint requests to: Patricia A. Cavazos-Rehg, Ph.D., Campus Box 8134, Department of Psychiatry, 660 South Euclid, St. Louis, MO 63110, Phone: (314) 362-2152, FAX: (314) 362-4247, rehgp@psychiatry.wustl.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.Conflicts of Interest Dr. Bierut is listed as an inventor on Issued U.S. Patent 8,080,371,"Markers for Addiction" covering the use of certain SNPs in determining the diagnosis, prognosis, and treatment of addiction. Implications and ContributionTwitter is a popular social media platform among young people. Results from this study highlight the pervasiveness of pro-marijuana Twitter chatter particularly among youth and African Americans and stress the need for more online marijuana prevention messages to target individuals who are most at-risk for marijuana use-associated harms. Twitter is a free-to-use social media platform that has become very popular among young people in recent years [1,2]. Twitter users can easily and instantly connect to a mass audience via Tweets that are 140 ...

Despite twin studies showing that 50–70% of variation in DSM-IV cannabis dependence is attributable to heritable influences, little is known of specific genotypes that influence vulnerability to cannabis dependence. We conducted a genomewide association study of DSM-IV cannabis dependence. Association analyses of 708 DSM-IV cannabis dependent cases with 2,346 cannabis exposed nondependent controls was conducted using logistic regression in PLINK. None of the 948,142 SNPs met genomewide significance (p < E−8). The lowest p-values were obtained for polymorphisms on chromosome 17 (rs1019238 and rs1431318, p-values at E−7) in the ANKFN1 gene. While replication is required, this study represents an important first step towards clarifying the biological underpinnings of cannabis dependence.

Whether for clinical or research purposes, the results emphasize the importance of directly assessing adolescents regarding alcohol and other substance use disorders. Furthermore, investigators should consider the specific disorder(s) being investigated and the ages of the children being studied when determining whether to include parent reports as part of study design.

Obesity is of global health concern. There are well-described inverse relationships between female pubertal timing and obesity. Recent genome-wide association studies of age at menarche identified several obesity-related variants. Using data from the ReproGen Consortium, we employed meta-analytical techniques to estimate the associations of 95 a priori and recently identified obesity-related (body mass index (weight (kg)/height (m)(2)), waist circumference, and waist:hip ratio) single-nucleotide polymorphisms (SNPs) with age at menarche in 92,116 women of European descent from 38 studies (1970-2010), in order to estimate associations between genetic variants associated with central or overall adiposity and pubertal timing in girls. Investigators in each study performed a separate analysis of associations between the selected SNPs and age at menarche (ages 9-17 years) using linear regression models and adjusting for birth year, site (as appropriate), and population stratification. Heterogeneity of effect-measure estimates was investigated using meta-regression. Six novel associations of body mass index loci with age at menarche were identified, and 11 adiposity loci previously reported to be associated with age at menarche were confirmed, but none of the central adiposity variants individually showed significant associations. These findings suggest complex genetic relationships between menarche and overall obesity, and to a lesser extent central obesity, in normal processes of growth and development.