Alcohol-induced blackouts among college student drinkers: A multilevel analysis

Factors that increase risk for alcohol-induced blackouts in high-intensity drinking young adults

BACKGROUND

Alcohol-induced blackouts are prospectively associated with negative drinking outcomes. While typically requiring heavy drinking, blackouts are not reported on all heavy drinking events or by all individuals who drink heavily. This study extends previous research by identifying the young adults most likely to experience blackouts assessed prospectively. Hypotheses focused on previously supported (female sex, White race, younger age, family history of alcohol problems, lower subjective response to alcohol, and higher tolerance) and novel predictors (possible traumatic brain injury; TBI) of alcohol-induced blackouts.

METHODS

Young adults (n = 203, 57% female, Mage = 22.07) recruited for high-intensity drinking (8/10+ drinks/occasion for females/males) completed a baseline survey and a 28-day ecological momentary assessment protocol. Hierarchical linear modeling was used to test between-person predictors of fragmentary (temporary) or en bloc (permanent) blackout likelihood during the 28 days, and moderators of the effect of day-level estimated blood alcohol concentration (eBAC) on blackout likelihood.

RESULTS

Controlling for event-level and average eBAC, both types of blackouts were more likely among those with higher subjective response to alcohol. Fragmentary blackouts were more likely among younger participants and those with possible prior TBI. Day-level eBAC was more strongly associated with both types of blackouts among non-Hispanic White participants and those with lower mean eBACs. Day-level eBAC was most strongly associated with fragmentary blackouts among those with a first-order family history of alcohol problems.

CONCLUSIONS

Younger age and greater sensitivity to alcohol may confer risk for blackouts above and beyond intoxication levels. Future work is needed to understand mechanisms that explain why these factors confer risk for blackouts.

Longitudinal analysis for between- and within-person influences of descriptive alcohol drinking norms and attitudes on drinking outcomes

BACKGROUND

The study aimed to expand on existing research related to the theory of planned behavior (TPB) by exploring both between-person and within-person effects of descriptive norms and attitudes toward moderate and heavy drinking on drinking outcomes, including drinks per week, blackouts, and alcohol-related consequences. While previous studies focus on between-person effects, this study uniquely investigates both between-person effects as well as within-person changes over time, using longitudinal data collected at six points over 12 months.

METHODS

Participants included 484 mandated college students (Mage = 18.66, SDage = 0.758; 55.6% male). Participants completed measures of descriptive drinking norms, attitude toward moderate and heavy drinking, drinking intentions, and drinking outcomes, including drinks per week, blackout, and alcohol-related consequences. Multilevel models were run to examine the unique between-and within-person effects of descriptive drinking norms and attitude toward moderate and heavy drinking on drinking outcomes.

RESULTS

Overall, the results from the multilevel models showed that at the between-person level, descriptive norms were associated with drinks per week, and a more favorable attitude toward heavy drinking was associated with higher weekly alcohol consumption and related consequences. At the within-person level, within-person fluctuations in descriptive norms and attitude toward heavy drinking were associated with higher weekly drinking, blackout, and alcohol-related consequences, while favorable attitude toward moderate drinking were associated with lower odds of blackouts and fewer alcohol-related consequences.

CONCLUSIONS

Attitudes toward drinking, particularly heavy drinking, at both between-person and within-person levels, are strong predictors of alcohol use and its consequences. Furthermore, attitude toward moderate drinking are protective. Interventions promoting a moderate drinking attitude and reducing heavy drinking attitude and descriptive drinking norms will likely be effective in reducing alcohol-related harm.

Transdermal alcohol concentration features predict alcohol-induced blackouts in college students

BACKGROUND

Alcohol-induced blackouts (AIBs) are common in college students. Individuals with AIBs also experience acute and chronic alcohol-related consequences. Research suggests that how students drink is an important predictor of AIBs. We used transdermal alcohol concentration (TAC) sensors to measure biomarkers of increasing alcohol intoxication (rise rate, peak, and rise duration) in a sample of college students. We hypothesized that the TAC biomarkers would be positively associated with AIBs.

METHODS

Students were eligible to participate if they were aged 18-22 years, in their second or third year of college, reported drinking 4+ drinks on a typical Friday or Saturday, experienced ≥1 AIB in the past semester, owned an iPhone, and were willing to wear a sensor for 3 days each weekend. Students (N = 79, 55.7% female, 86.1% White, Mage = 20.1) wore TAC sensors and completed daily diaries over four consecutive weekends (89.9% completion rate). AIBs were assessed using the Alcohol-Induced Blackout Measure-2. Logistic multilevel models were conducted to test for main effects.

RESULTS

Days with faster TAC rise rates (OR = 2.69, 95% CI: 1.56, 5.90), higher peak TACs (OR = 2.93, 95% CI: 1.64, 7.11), and longer rise TAC durations (OR = 4.16, 95% CI: 2.08, 10.62) were associated with greater odds of experiencing an AIB.

CONCLUSIONS

In a sample of "risky" drinking college students, three TAC drinking features identified as being related to rising intoxication independently predicted the risk for daily AIBs. Our findings suggest that considering how an individual drinks (assessed using TAC biomarkers), rather than quantity alone, is important for assessing risk and has implications for efforts to reduce risk. Not only is speed of intoxication important for predicting AIBs, but the height of the peak intoxication and the time spent reaching the peak are important predictors, each with different implications for prevention.

A latent profile analysis of social anxiety, depression, and pregaming motives among heavy-drinking college students

BACKGROUND

Pregaming is a high-risk drinking behavior that is associated with heavy drinking and negative alcohol-related consequences. College students may engage in pregaming for several reasons, including to enhance social experiences or cope with negative affect. Research shows that associations between drinking, social anxiety, and depression are multifaceted. However, our understanding of the complex associations of mental health symptoms with pregaming motives and behaviors remains limited.

METHODS

This study examined heterogeneity in how pregaming motives, social anxiety, and depression associate with past 30-day pregaming variables (quantity, frequency, and negative consequences). We used latent profile analysis (LPA) in a sample of heavy-drinking university students (N = 479).

RESULTS

LPA results indicated four profiles: mild/moderate social anxiety and depression symptoms, moderate motives (n = 285), minimal social anxiety and depression symptoms, low motives (n = 61), subclinical/elevated social anxiety and depression symptoms, high motives (n = 75), and clinically elevated social anxiety and depression symptoms, moderate motives (n = 58). The subclinical/elevated symptoms, high motives profile reported the highest pregaming frequency and consequences, including blackouts. Individuals in the clinically elevated symptoms, moderate motives profile reported more consequences than those in the minimal symptoms, low motives and mild/moderate symptoms, moderate motives profiles. Individuals in the minimal symptoms, low motives profile reported the fewest consequences.

CONCLUSIONS

Among these students, social anxiety and pregaming motives were associated with more frequent pregaming and social anxiety and depression were associated with greater negative consequences. Interventions that target pregaming-specific motives among students with mental health symptoms may be warranted to reduce this risky behavior and associated drinking-related harm.

Does it really matter that I do not remember my night? Consequences related to blacking out among college student drinkers

BACKGROUND

Alcohol-induced blackouts (AIBs) are experienced frequently by college student drinkers and are more likely to occur on days with high-intensity drinking (HID; 8+ for females/10+ for males) than non-HID days. Research suggests that AIBs are associated with experiencing other alcohol-related consequences (ARCs), including more serious ARCs (SARCs; e.g., legal and sexual consequences), but we do not know whether individuals experience more ARCs and more SARCs on occasions when they black out than when they do not black out. This study examines the associations between AIBs and the total number of both ARCs and SARCs.

METHODS

Students (N = 462, 51.7% female, 87.7% White, Mage  = 20.1) were assessed across 6 weekends via e-surveys (80%-97% response rate). Multilevel models were used to test for main effects, controlling for drinking (HID or estimated blood alcohol concentration; eBAC) and sex.

RESULTS

Drinking days when an AIB was experienced were associated with more total ARCs (b = 3.54, 95% CI: 3.10, 3.99) and more SARCs (b = 0.77, 95% CI: 0.60, 0.95) per day than non-AIB days. The more frequently a person experienced an AIB, the more total ARCs (b = 5.33, 95% CI: 4.40, 6.25) and SARCs (1.05, 95% CI: 0.80, 1.30) they reported on average.

CONCLUSION

Alcohol-induced blackout days were associated with higher levels of harm than non-AIB days, even at the same levels of drinking. Interventions that focus on reducing the occurrence of AIBs and factors that contribute to them, in addition to reducing alcohol consumption, may help reduce total harm associated with drinking among college students.