Daily Stress, Drinking Motives and Alcohol Co-Use with Other Drugs.

Background: Recent evidence indicates that alcohol and other substance co-use, compared to alcohol-only use, might be more closely associated with negative reinforcement processes, and thus more likely during periods of increased stress. The present study examined this possibility by using data from an intensive longitudinal (daily) study of college student drinkers (N = 1461, 54% women). We also examined individual differences in coping and enhancement drinking motives as predictors of alcohol and other substance co-use. Results: We used multilevel multinomial logistic regression to predict, relative to alcohol-only days, the likelihood of alcohol co-use with either cigarettes or marijuana, along with alcohol use with multiple substances and other substance-only use from daily interpersonal and academic stress, day-of-the-week, sex, and individual differences in coping and enhancement drinking motives. We found that, relative to alcohol-only, alcohol and marijuana co-use was more likely, and non-alcohol related substance use was less likely, on weekends. Alcohol and marijuana co-use was less likely, and other substance-only use was more likely, on days characterized by greater academic stress, whereas alcohol and cigarette co-use was more likely on days characterized by greater interpersonal stress. Individuals with higher levels of drinking to cope motivation were more likely to engage in alcohol and cigarette co-use, other substance-only use, and alcohol plus multiple substances, relative to alcohol-only. Individuals with higher levels of enhancement motives were more likely to engage in all types of alcohol and other substance co-use and other substance-only use relative to alcohol-only. Conclusions: Findings are discussed in terms of the complex nature of different patterns of co-use patterns when evaluating indicators of positive- and negative-reinforcement processes.

Individual Differences in Affect Dynamics and Alcohol-Related Outcomes.

Background: To examine whether individual differences in intensive longitudinal data-derived affective dynamics (i.e. positive and negative affect variability and inertia and positive affect-negative affect bipolarity) - posited to be indicative of emotion dysregulation - are uniquely related to drinking level and affect-regulation drinking motives after controlling for mean levels of affective states. Method: We used a large sample of college student drinkers (N = 1640, 54% women) who reported on their affective states, drinking levels and drinking motives daily for 30 days using a web-based daily diary. We then calculated from the daily data positive and negative affect variability, inertia, affect bipolarity and mean levels of affect and used these as predictors of average drinking level and affect-regulation drinking motives (assessed using both retrospective and daily reporting methods). Results: Findings from dynamic structural equation models indicated that mean levels of affect were uniquely related to drinking motives, but not drinking level. Few dynamic affect predictors were uniquely related to outcomes in the predicted direction after controlling for mean affect levels. Conclusion: Our results add to the inconsistent literature regarding the associations between affective dynamics and alcohol-related outcomes, suggesting that any effects of these indicators, after controlling for mean affect levels, might be more complex than can be detected with simple linear models.

A daily study of stressors, continuously measured glucose, and diabetes symptoms in latinos with type 2 diabetes.

This study examined whether daily stressors and continuously monitored glucose levels and glucose variability predict daily diabetes symptoms. Fifty Latinos with type 2 diabetes were randomized to either diabetes education (DE-only; N = 23) or DE plus stress management and relaxation training (DE + SMR; N = 32). After treatment, for 7 days they wore 'blinded' continuous glucose monitors and reported common stressors and diabetes symptoms twice daily. Between individuals, participants with more numerous overall stressors and more time in hyperglycemia reported higher symptoms. Within individuals, symptoms were higher during intervals of greater than usual stressors. Yet, diabetes symptoms did not covary with changes in glucose levels or glucose variability. The within-person stressor-symptom association was stronger among older individuals and non-significant for participants in DE + SMR condition. Diabetes symptoms were associated with recent stressor exposure, but not recent glucose level or changes in glucose. CLINICAL TRIAL NUMBER: ClinicalTrials.gov Identifier (No. NCT01578096).

Fluctuations in daily PTSD symptoms are related to proximal alcohol use: a micro-longitudinal study of women victims of intimate partner violence.

Background: One-third of women who experience intimate partner violence (IPV) are identified as having alcohol use problems. Yet, little research has examined factors that may increase the risk of alcohol use among this high-risk population. Objectives: This study overcomes limitations of previous research by using micro-longitudinal methods to examine how fluctuations in PTSD symptoms throughout the day are associated with proximal drinking behavior and whether these associations are related to individuals' overall PTSD severity and race/ethnicity. Methods: Using phone-based interactive voice response, 244 female victims of current IPV reported their PTSD symptoms and drinking four times daily for 14 days. Results: Results indicated positive associations between PTSD symptom cluster severity and drinking level at the person, daily and within-day levels. The effects of within-person fluctuations in daily levels of PTSD severity on levels of drinking were stronger for individuals with lower PTSD severity. No evidence was found for within-person differences on time-lagged effects of PTSD on drinking or by racial/ethnic group. Further, in time-lagged models no evidence was found for reverse causation whereby alcohol use predicts increased PTSD symptom severity. Conclusions: Findings suggest that IPV-exposed women use alcohol to alleviate their PTSD symptoms at the micro-process level and that prevention and treatment efforts targeting PTSD symptoms may be useful in reducing alcohol use in this population. Further, these efforts should consider the overall severity of PTSD symptoms experienced given the differential findings among women with higher vs. lower PTSD symptom severity.

Mean Levels and Variability in Affect, Diabetes Self-Care Behaviors, and Continuously Monitored Glucose: A Daily Study of Latinos With Type 2 Diabetes.

OBJECTIVE: This study investigated between- and within-person associations among mean levels and variability in affect, diabetes self-care behaviors, and continuously monitored glucose in Latinos with type 2 diabetes. METHODS: Fifty participants (M [SD] age = 57.8 [11.7] years, 74% women, mean [SD] glycosylated hemoglobin A1c = 8.3% [1.5%]) wore a "blinded" continuous glucose monitor for 7 days, and they responded to twice daily automated phone surveys regarding positive affect, negative affect, and self-care behaviors. RESULTS: Higher mean levels of NA were associated with higher mean glucose (r = .30), greater percent hyperglycemia (r = .34) and greater percentage of out-of-range glucose (r = .34). Higher NA variability was also related to higher mean glucose (r = .34), greater percent of hyperglycemia (r = .44) and greater percentage of out-of-range glucose (r = .43). Higher positive affect variability was related to lower percentage of hypoglycemia (r = -.33). Higher mean levels of self-care behaviors were related to lower glucose variability (r = -.35). Finally, higher self-care behavior variability was related to greater percentage of hyperglycemia (r = .31) and greater percentage of out-of-range glucose (r = -.28). In multilevel regression models, within-person increases from mean levels of self-care were associated with lower mean levels of glucose (b = -7.4, 95% confidence interval [CI] = -12.8 to -1.9), lower percentage of hyperglycemia (b = -0.04, 95% CI = -0.07 to -0.01), and higher percentage of hypoglycemia (b = 0.02, 95% CI = 0.01 to 0.03) in the subsequent 10-hour period. CONCLUSIONS: Near-to-real time sampling documented associations of glucose with affect and diabetes self-care that are not detectable with traditional measures.

Self-efficacy mediates the effects of topiramate and GRIK1 genotype on drinking.

Previous studies indicate that topiramate reduces alcohol use among problem drinkers, with one study showing that the effect was moderated by a polymorphism (rs2832407) in GRIK1, the gene encoding the GluK1 kainate subunit. We examined whether the interactive effect of medication and genotype (1) altered the association between daily self-efficacy and later-day drinking; and (2) had an indirect effect on drinking via self-efficacy. In a 12-week, placebo-controlled trial of topiramate, we used daily interactive voice response technology to measure self-efficacy (i.e. confidence in avoiding heavy drinking later in the day) and drinking behavior in 122 European-American heavy drinkers. Topiramate's effects on both self-efficacy and drinking level were moderated by rs2832407. C-allele homozygotes treated with topiramate showed higher levels of self-efficacy and lower levels of nighttime drinking across the 12-week trial. Further, the interactive effect of topiramate and genotype on mean nighttime drinking levels was mediated by mean levels of self-efficacy. By modeling topiramate's effects on nighttime drinking across multiple levels of analysis, we found that self-efficacy, a key psychologic construct, mediated the effect of topiramate, which was moderated by rs2832407 genotype. Thus, it may be possible to use an individualized assessment (i.e. genotype) to select treatment to optimize the reduction in heavy drinking and thereby provide a personalized treatment approach.

PTSD and Daily Co-Occurrence of Drug and Alcohol Use Among Women Experiencing Intimate Partner Violence.

OBJECTIVE: People with posttraumatic stress disorder (PTSD) are at high risk for substance use, and PTSD is common among women experiencing intimate partner violence. Considering the effects of both PTSD and substance use, such as poorer treatment outcomes and greater health/behavior problems, women experiencing intimate partner violence are a high-risk, under-researched group. METHODS: We utilized a micro-longitudinal study design to assess daily drug and alcohol use over 21 days among 41 women experiencing intimate partner violence recruited from the community. RESULTS: Participants were about 45 years old (M = 45.1, SD = 8.5) and mostly African American (n = 32, 78%). Co-occurrence of drug and alcohol use was reported on 19.0% of days, while drug use alone occurred on 13.4% of days and alcohol use on 12.1%. Fifteen percent of participants met current PTSD criteria, with a mean symptom severity rating of 15.90 (SD = 10.94, range 0 to 47). Women with PTSD, compared to those without, were nearly 15 times more likely to have days of co-occurrence of drug and alcohol use (p = .037) and nearly 7 times more likely to have days of drug use alone (p = .044). CONCLUSIONS: These findings indicate that the combination of intimate partner violence and PTSD may make women especially prone to daily co-occurring drug and alcohol use or drug use alone. Further research is needed to explore this association and examine the need for integrated programs to support victims' health, prevent the development of substance use problems, and facilitate recovery from PTSD and substance use.

FKBP5 genotype interacts with early life trauma to predict heavy drinking in college students.

Alcohol use disorder (AUD) is debilitating and costly. Identification and better understanding of risk factors influencing the development of AUD remain a research priority. Although early life exposure to trauma increases the risk of adulthood psychiatric disorders, including AUD, many individuals exposed to early life trauma do not develop psychopathology. Underlying genetic factors may contribute to differential sensitivity to trauma experienced in childhood. The hypothalamic-pituitary-adrenal (HPA) axis is susceptible to long-lasting changes in function following childhood trauma. Functional genetic variation within FKBP5, a gene encoding a modulator of HPA axis function, is associated with the development of psychiatric symptoms in adulthood, particularly among individuals exposed to trauma early in life. In the current study, we examined interactions between self-reported early life trauma, past-year life stress, past-year trauma, and a single nucleotide polymorphism (rs1360780) in FKBP5 on heavy alcohol consumption in a sample of 1,845 college students from two university settings. Although we found no effect of early life trauma on heavy drinking in rs1360780*T-allele carriers, rs1360780*C homozygotes exposed to early life trauma had a lower probability of heavy drinking compared to rs1360780*C homozygotes not exposed to early life trauma (P < 0.01). The absence of an interaction between either current life stress or past-year trauma, and FKBP5 genotype on heavy drinking suggests that there exists a developmental period of susceptibility to stress that is moderated by FKBP5 genotype. These findings implicate interactive effects of early life trauma and FKBP5 genetic variation on heavy drinking. © 2016 Wiley Periodicals, Inc.

GRIK1 genotype moderates topiramate's effects on daily drinking level, expectations of alcohol's positive effects and desire to drink.

We (Kranzler et al., 2014) reported that topiramate 200 mg/day reduced heavy drinking days and increased abstinent days in 138 heavy drinkers whose treatment goal was to reduce drinking to safe levels. In that 12-week, placebo-controlled study, we measured drinking using the Timeline Follow-back method at each treatment visit. In addition to the intent-to-treat effects of topiramate, we found that a single nucleotide polymorphism (rs2832407) in GRIK1, encoding the GluK1 subunit of the kainate receptor, moderated the treatment effect in European Americans (EAs; n = 122). Topiramate reduced heavy drinking only in rs2832407*C allele homozygotes. Here, we augment those analyses by using patients' daily reports obtained using interactive voice response technology; (a) to validate the interactive effects of GRIK1 and topiramate as predictors of drinking level; and, (b) to examine changes in expected positive effects of drinking (i.e. positive outcome expectancies) and desire to drink. We found that rs2832407*C allele homozygotes treated with topiramate drank less overall during treatment than those receiving placebo, validating our earlier findings for heavy drinking days (Kranzler et al., 2014). There was also a study day × medication group × genotype group interaction that predicted both positive alcohol expectancies and desire to drink, with rs2832407*C-allele homozygotes treated with topiramate showing the largest decreases in these outcomes during the study period. Changes in positive alcohol expectancies or desire to drink did not mediate the effects on drinking. These findings validate and extend our previous pharmacogenetic findings with topiramate.

Body checking and avoidance among dancers.

Dancers are at heightened risk for eating disorders (EDs) and have job and training demands that obscure ED assessment and likely impede treatment. Two behavioral manifestations of ED psychopathology that may present uniquely in a dance environment are body checking and body avoidance. The current study sought to provide a foundational understanding of the phenomenology of body checking and avoidance among dancers by assessing the reliability (i.e., internal consistency) of existing body checking and avoidance measures and the relationships, or convergent validity, between measures of body checking and avoidance and measures of related constructs. Eighty professional and pre-professional (i.e., conservatory level) dancers (78.8 % female) from seven dance genres completed self-report measures of body checking and avoidance, ED pathology, clinical perfectionism, depression, and anxiety. Across the dancer sample, body checking and avoidance measures demonstrated adequate internal consistency. More frequent body checking and body avoidance was strongly related to higher levels of ED pathology. There were moderate to strong correlations between body checking and body avoidance and clinical perfectionism, depression, and anxiety such that higher body checking and body avoidance was related to higher clinical perfectionism, depression, and anxiety. Exploratory analyses found no significant differences between ballet dancers and dancers of other dance genres; professional dancers scored in the normative range on measures of body checking and body avoidance. Dancers' qualitative descriptions of body checking and avoidance revealed behaviors not included in existing questionnaires, such as unique mirror use behaviors, technology-assisted body checking, and the checking and avoidance of body parts relevant to the dance-specific body ideal. Results support the inclusion of body checking and avoidance interventions in ED treatments for dancers (particularly pre-professional dancers) and emphasize the need for dancer-specific ED assessment methods.

Variation in OPRM1 moderates the effect of desire to drink on subsequent drinking and its attenuation by naltrexone treatment.

To evaluate the role of the functional Asn40Asp polymorphism in the mu-opioid receptor gene on drinking behavior and naltrexone's ability to attenuate drinking, we used a daily diary method in a 12-week, randomized clinical trial of naltrexone to reduce drinking. Participants (n = 158 problem drinkers) were assigned to receive either daily or targeted naltrexone 50 mg (n = 81) or matching placebo (n = 77). Patients reported by telephone each evening their current desire to drink and their drinking during the previous night and during the reporting day. We examined genotype, medication, desire to drink and their interactions as predictors of nighttime drinks consumed, controlling for drinking earlier in the day. Asp40 carriers showed a stronger positive association between evening desire (deviations from their mean levels) and later night drinking levels than Asn40 homozygotes (P = 0.019). The desire × genotype × medication condition interaction was also significant (P = 0.009), with a significant desire × genotype interaction for the placebo group (P = 0.001) but not for the naltrexone group (P = 0.74). In summary, when the evening level of desire to drink was relatively high, Asp40 allele carriers were at greater risk than Asn40 homozygotes to drink more, which was attenuated by naltrexone. Although average measures across the study were not informative, daily reports helped to demonstrate the moderating effects of genetic variation on the relation between desire to drink and alcohol consumption and the effects of naltrexone on that phenotype.

5-HTTLPR genotype and daily negative mood moderate the effects of sertraline on drinking intensity.

We previously reported moderating effects of age of onset of alcohol dependence (AD) and a functional polymorphism (5-HTTLPR) in the gene encoding the serotonin transporter protein in a sample of 134 individuals participating in a 12-week, placebo-controlled trial of sertraline. To understand more fully the effects seen in that study, we examined moderation by negative moods reported each evening, with nighttime drinking intensity (i.e. the number of standard drinks consumed at night) as the dependent variable. We found a daily anxiety × age of onset × 5-HTTLPR polymorphism × medication interaction, which reflected a daily anxiety × medication group effect for early-onset individuals homozygous for the high-expression (L') allele, but not others. Specifically, on days characterized by relatively high levels of anxiety, early-onset L' homozygotes receiving placebo reduced their drinking intensity significantly. In contrast, early-onset L' homozygotes treated with sertraline non-significantly increased their drinking intensity. These findings implicate anxiety as a key moderator of the observed pharmacogenetic effects. These findings have important implications because of the high prevalence of AD and the frequency with which SSRIs are prescribed to treat the disorders.

Ignoring Norms with a Little Help from My Friends: Social Support Reduces Normative Influence on Drinking Behavior.

Alcohol norms are strong predictors of drinking. However, the extent to which norms influence behavior depends on how closely people attend to them; people are more likely to attend to norms when their affiliation needs are unfulfilled by members of their social networks (Cullum, O'Grady, & Tennen, 2011). Therefore, we predicted that Perceived Social Support (PSS) would moderate the relationship between norms and drinking such that people with low levels of PSS would be more motivated to attend to norms. College students (N = 498) completed measures of PSS and peer alcohol norms and then reported on their drinking behavior daily for 30 days. As predicted, we found when PSS was low, student drinking was strongly influenced by peer norms, but there was no relationship between norms and drinking when PSS was high. Findings suggest that when affiliation needs are high, norms are more influential on drinking behavior.

Join the Party: Approval-Contingent Self-Worth, Drinking Motives, and Drinking Alone and With Others.

OBJECTIVE: Research links approval-contingent self-worth to college drinking but has not differentiated social and solitary consumption. High approval-contingent self-worth individuals might drink socially to derive approval. METHOD: In a sample of 832 undergraduates, approval-contingent self-worth and drinking motives were measured in an initial questionnaire, and social and solitary consumption were reported daily for 30 days. RESULTS: Results indicated an overall positive association between approval-contingent self-worth and social consumption and positive indirect effects via social and enhancement motivations, but a negative indirect effect via conformity motivation. The association between approval-contingent self-worth and solitary alcohol consumption was nonsignificant because of a negative direct effect counteracted by a positive total indirect effect. CONCLUSIONS: Results highlight the importance of drinking motives and of distinguishing between social and solitary consumption.

Too tired to drink? Daily associations of sleep duration and fatigue with own and others' alcohol consumption.

OBJECTIVE: To better understand how sleep is associated with alcohol consumption among college students, the present study tested whether last night's sleep duration and current day fatigue were associated with being around others who were drinking that night and, if so, with alcohol consumption. METHOD: College student drinkers (N = 540; mean age = 18.78 years; 52% female; 86% White) reported daily for 30 days yearly for up to 4 years on aspects of their sleep, their own alcohol use, and the perceived drinking of others in an intensive longitudinal burst design. RESULTS: Participants were less likely to report that they were with others who were drinking on evenings following higher than average sleep duration or greater than average daytime fatigue. In addition, experiencing greater than average daytime fatigue was associated with a lower likelihood of consuming any alcohol and lower levels of alcohol consumption at the daily level. Thus, daytime fatigue may be protective against alcohol consumption through both selection and behavior moderation. CONCLUSIONS: Results may be useful in the development of interventions to prevent heavy drinking among college students. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The daily association between affect and alcohol use: A meta-analysis of individual participant data.

Influential psychological theories hypothesize that people consume alcohol in response to the experience of both negative and positive emotions. Despite two decades of daily diary and ecological momentary assessment research, it remains unclear whether people consume more alcohol on days they experience higher negative and positive affect in everyday life. In this preregistered meta-analysis, we synthesized the evidence for these daily associations between affect and alcohol use. We included individual participant data from 69 studies (N = 12,394), which used daily and momentary surveys to assess affect and the number of alcoholic drinks consumed. Results indicate that people are not more likely to drink on days they experience high negative affect, but are more likely to drink and drink heavily on days high in positive affect. People self-reporting a motivational tendency to drink-to-cope and drink-to-enhance consumed more alcohol, but not on days they experienced higher negative and positive affect. Results were robust across different operationalizations of affect, study designs, study populations, and individual characteristics. These findings challenge the long-held belief that people drink more alcohol following increases in negative affect. Integrating these findings under different theoretical models and limitations of this field of research, we collectively propose an agenda for future research to explore open questions surrounding affect and alcohol use.

Post-treatment outcomes in a double-blind, randomized trial of sertraline for alcohol dependence.

BACKGROUND: Pharmacotherapy studies in alcohol dependence (AD) are generally of short duration and do not include post-treatment follow-up. We examined the durability of treatment effects in a placebo-controlled trial of sertraline for AD. METHODS: As previously reported, patients received 12 weeks of treatment with sertraline (n = 63) or placebo (n = 71), followed by assessments at 3 and 6 months post-treatment (Kranzler et al., 2011, J Clin Psychopharmacol 31:22-30). We examined the main and interaction effects with time of 3 between-subject factors (medication group, age of onset of AD [late-onset alcoholics, LOAs, vs. early-onset alcoholics, EOAs], and the tri-allelic 5-HTTLPR genotype) on drinking days (DDs) and heavy drinking days (HDDs). RESULTS: The medication group effect, which was significant during treatment, remained significant during the 3-month follow-up period for L'/L' LOAs, with the sertraline group having fewer DDs than the placebo group (p = 0.027). However, the medication group effect seen in L'/L' EOAs during treatment was no longer significant (p = 0.48). There were no significant effects in S' carriers at the 3-month follow-up visit, or in either genotype group at the 6-month follow-up. CONCLUSIONS: The beneficial effects of sertraline observed in LOAs during treatment persisted during the 3-month post-treatment period. Additional studies are needed to validate these pharmacogenetic findings, which together with the effects seen during active treatment support the use of sertraline only in LOAs.

Comparison of alcoholism subtypes as moderators of the response to sertraline treatment.

BACKGROUND: A variety of typologies have been used to categorize alcoholism's diverse manifestations. Although the most widely studied typologies are dichotomous ones based on genetic epidemiologic findings or using cluster analytic methods, recent efforts have utilized a single item or the onset of a diagnosis of alcohol dependence to subtype individuals based on the age of alcoholism onset. We compared 3 different methods to subtype alcoholics. METHODS: This secondary analysis used data from 134 alcohol-dependent participants in a placebo-controlled trial of sertraline (Kranzler et al., 2011). We compared cluster analysis to distinguish 2 risk/severity subtypes (Babor et al., 1992) with 2 age-of-onset subtypes (i.e., based on the age of onset of problem drinking or the age at which alcohol dependence criteria were first met). RESULTS: Each method yielded subgroups that differed significantly from one another on demographic and clinical measures. Although concordance was high between the 2 age-of-onset methods, it was poor between the age-of-onset methods and the cluster analysis-derived approach. All 3 subtyping approaches significantly moderated the effects of sertraline or placebo, but only in the L'L' genotype group, as originally reported (Kranzler et al., 2011). In all cases, sertraline treatment was superior to placebo in later-onset individuals and inferior to placebo in the earlier-onset groups. CONCLUSIONS: Because age-of-onset subtypes can be defined retrospectively on an individual basis, they may be more clinically useful than cluster-derived subtypes, which require group data. Because the 2 age-of-onset measures we examined appear to have comparable validity, a single item is easier to use as a measure of the age of onset of problem drinking.

Change and Stability in Active and Passive Social Influence Dynamics during Natural Drinking Events: A Longitudinal Measurement-Burst Study.

We examined the link between social norms and active social influences occurring during natural social drinking contexts. Across 4 yearly measurement-bursts, college students (N = 523) reported daily for 30-day periods on drinking norms, drinking offers, how many drinks they accepted, and personal drinking levels during social drinking events. In contexts where drinking norms were higher, students were more likely to both receive and comply with drinking offers. These acute social influences were highly stable throughout college, but affected men and women differently across time: Women received more drinking offers than men, especially at the beginning of college and when norms were higher, but men complied with more drinking offers per occasion. These effects were not attributable to between-person differences in social drinking motives or drinking levels, nor to within-person patterns of situation-selection. The present work suggests that context-specific drinking norms catalyze active social influence attempts, and further promote compliance drinking.

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

Covault et al. [Covault et al. (2007); Biol Psychiatry 61(5): 609-616] 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. 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. 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). 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.