The 5‐HTTLPR polymorphism moderates the effect of stressful life events on drinking behavior in college students of African descent

Abstract

Background Covault et al. (2007) reported that the common functional polymorphism, 5-HTTLPR, in the serotonin transporter gene moderated the association between past-year stressful events and daily reports of drinking in a sample of European-American (EA) college students. We examined this effect in college students of African descent. Methods Students recruited at a Historically Black University (n=564) completed web-based measures of past-year stressful life experiences and daily reports of drinking and heavy drinking over a 30-day period. Participants were genotyped for the tri-allelic 5-HTTLPR polymorphism and dichotomized as low-activity S’ allele carriers or high-activity L’ homozygotes. Generalized linear models were used to examine the effects of life stress, genotype, and their interaction on the two drinking measures. Results In students who completed 15 or more daily surveys (n=393), there was a significant interaction of past-year stressful events, 5-HTTLPR genotype, and gender on the number of drinking days (p=0.002). Similar findings were obtained in relation to heavy drinking days (p=0.007). Men showed a main effect of past-year stressful events on both drinking outcomes (p’s<0.001), but no main or moderator effects of genotype. In women, the S’ allele moderated the impact of past-year life stressors on the frequency of drinking and heavy drinking days (p’s<0.001). Conclusions In college students of African descent, past-year stressful events were associated with more frequent drinking and heavy drinking, an effect that was moderated by the 5-HTTLPR polymorphism. However, in contrast to the findings in EA students, in the current sample, 5-HTTLPR moderated the association only among women.

Serotonin transporter genotype by environment: Studies on alcohol use and misuse in non-human and human primates

“…Ten studies estimating the associations of an interaction between the 5-HTTLPR genotype and an environmental factor with alcohol use and misuse were found, two that examined rhesus monkeys [28,30] and eight that examined humans [29,[31][32][33][34][35][36][37]. Descriptions of the studies are presented in Tables 1 and 2.…”

“…Studies recruited participants through flyers, advertisements, emails [34,36], questionnaires on youth psychosocial health [29,31,33,35], and from treatment programs [32,37]. Four of the eight studies of humans were longitudinal [31][32][33]35], and four cross-sectional [29,34,36,37].…”

“…Four of the eight studies of humans were longitudinal [31][32][33]35], and four cross-sectional [29,34,36,37]. One study was a family based study design [32].…”

“…The genotyping techniques used were polymerase chain reaction (PCR) followed by sequence detection in four studies [29,34,36], and PCR followed by gel electrophoresis in three studies [33,35,37]. Two studies did not report the method used [31,32].…”

“…The Vaske et al [31]. Two studies also assessed the SNP rs25531 within the 5-HTTLPR [33,36], with the following weighted mean genotype…”