OPRM1 rs1799971 Genotype Predicts Drinking Behavior in Males, but Not Females

• The prevalence of alcohol disorders costs Americans $223.5 billion yearly due mostly from losses in workplace productivity, as well as health care and criminal justice expenses (CDC, 2016). • Maximum number of drinks consumed in a 24 hour period is a valid indicator of dangerous drinking behavior and may reflect an increased tolerance for high levels of alcohol (Edenberg, 2016). • Awareness of factors related to such heavy drinking is important for targeting interventions for dangerous alcohol use. • Men drink significantly more than women, with about 4.5% of men and 2.5% of women meeting the diagnostic criteria for alcohol dependence in 2013 (Wilsnack, et al., 2000), (Esser et al., 2014). • Alcoholism is highly heritable and the endogenous opioid system has been shown to play a vital role in alcohol and other drug dependencies (Miranda et al., 2010). • The mu-opioid receptor gene (OPRM1) is involved in a variety of pathological conditions, such as alcohol use disorder (AUD). The polymorphism has been shown to modulate sensitivity to alcohol (Bart, et al., 2005), (Sauriyal et al., 2011), (Mauge and Blendy, 2010). • Carriers of the G allele for rs1799971, a polymorphism of OPRM1, result in an amino acid change at position 40 of the mu opioid receptor, and express receptors with 3 times higher affinity to Β-endorphins, and this has been associated with an increased risk for substance and alcohol dependence (Miranda et al., 2010), (Zhang, et al., 2005). • There is more social pressure on females to abstain from alcohol use, so it is possible that this effect will be weaker for females due to the competing effect of social pressure (Nolen-Hoeksema, 2004). • We hypothesize that individuals with at least one G allele will have a higher number of maximum drinks consumed within 24 hours than A homozygotes. • We expect this effect to be stronger in males than in females. • We also expect that males will drink more than females