Association of Alcohol Use Disorder Risk With ADH1B, DRD2, FAAH, SLC39A8, GCKR, and PDYN Genetic Polymorphisms.

BACKGROUND/AIM: Alcohol use disorder (AUD) is a chronic, multifactorial psychiatric condition with an enormous impact on public health and social cost. Genetic studies suggest a heritability, and genome-wide association studies (GWAS) have revealed genetic polymorphisms influencing AUD development. Our study aimed to investigate known variants located in ADH1B, DRD2, FAAH, SLC39A8, GCKR, and PDYN genes (rs1229984, rs7121986, rs324420, rs13107325, rs1260326, rs2281285 respectively) in an AUD Greek cohort in order to shed more light on the genetic predisposition to AUD. MATERIALS AND METHODS: Alcohol-dependent individuals (n=251) meeting both the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the ICD-10 guidelines for alcohol abuse and dependence, and control individuals (n=280) were recruited. DNA was extracted from whole blood and PCR-restriction fragment length polymorphism (RFLP-PCR) or allele-specific PCR method was used for genotyping. RESULTS: Individuals carrying the FAAH rs324420 A allele were significantly associated with increased risk of AUD (p<0.0001). SLC39A8 rs13107325 T allele and ADH1B rs1229984 T allele are overrepresented in control subjects (p<0.0001 and p<0.0001, respectively). The associations are maintained following an adjustment for age and sex and Bonferroni correction. GCKR rs13107325, DRD2 rs7121986, and PDYN rs2281285 polymorphisms did not show a significant association with AUD in the studied population after Bonferroni correction. CONCLUSION: Susceptibility to AUD is related to variations in FAAH, ADH1B, and SLC39A8 genes. These polymorphisms could serve as potential biomarkers for AUD risk.

Identification of heavy drinking in the 10-item AUDIT: Results from a prospective study among 18-21years old non-dependent German males.

BACKGROUND: Alcohol consumption is pivotal for the subsequent development of alcohol use disorders (AUD). The Alcohol Use Disorders Identification Test (AUDIT) is a recommended AUD screening tool for prevention and primary care settings. The objectives of this study were to test how many participants with heavy drinking are unidentified by the AUDIT, if proportions of unidentified participants vary over time, and whether this unidentified risk group (URG) was clinically relevant in terms of drinking behavior reports and AUD risk factors, as well as future adverse outcomes, such as craving, dependence symptoms, or depression. METHODS: Our prospective cohort study followed 164 German males aged 18-19years without an alcohol dependence diagnosis over 24months. Only men were included due to higher AUD prevalence and gender-specific differences in metabolism, drinking patterns, and progression to AUD. All participants were screened via telephone interview and answered questionnaires both in person and via internet. Heavy drinking was classified using the AUDIT consumption score (AUDIT-C≥4.50). Standardized AUD diagnoses and symptoms, as well as alcohol use-related outcome criteria were assessed via standardized Composite International Diagnostic Interview (CIDI), and self-report questionnaires. RESULTS: One in four participants (22-28% across all four follow-ups) reported heavy drinking but was unidentified by AUDIT total score (i.e. score<8), thus qualifying for URG status. The URG status did not fluctuate considerably across follow-ups (repeated-measures ANOVA, p=0.293). URG participants identified at the six-month follow-up did not generally differ from participants without URG status in terms of AUD family history or temperament (multivariate ANOVA, p=0.114), except for anxiety sensitivity (pBonferroni<0.001). After two years, URG participants reported a similar level of adverse outcomes compared to low-risk participants (multivariate ANOVA, p=0.438), but less alcohol-related problems and less loss of control due to craving compared to high-risk participants (pBonferroni≤0.007). CONCLUSIONS: Despite the considerable number of heavy-drinking individuals unidentified by AUDIT total scores, an additional classification according to AUDIT-C values did not prove useful. Combining AUDIT and AUDIT-C scores might not be sufficient for identifying AUD risk groups among young adult German males. There is an urgent need for a replication of our findings among female participants.