Predictors of Subgroups Based on Maximum Drinks per Occasion Over Six Years for 833 Adolescents and Young Adults in COGA

Abstract

ABSTRACT. Objective: A person's pattern of heavier drinking often changes over time, especially during the early drinking years, and refl ects complex relationships among a wide range of characteristics. Optimal understanding of the predictors of drinking during times of change might come from studies of trajectories of alcohol intake rather than crosssectional evaluations. Method: The patterns of maximum drinks per occasion were evaluated every 2 years between the average ages of 18 and 24 years for 833 subjects from the Collaborative Study on the Genetics of Alcoholism. Latent class growth analysis identifi ed latent classes for the trajectories of maximum drinks, and then logistic regression analyses highlighted variables that best predicted class membership. Results: Four latent classes were found, including Class 1 (69%), with about 5 maximum drinks per occasion across time; Class 2 (15%), with about 9 drinks at baseline that increased to 18 across time; Class 3 (10%), who began with a maximum of 18 drinks per occasion but decreased to 9 over time; and Class 4 (6%), with a maximum of about 22 drinks across time. The most consistent predictors of higher drinking classes were female sex, a low baseline level of response to alcohol, externalizing characteristics, prior alcohol and tobacco use, and heavier drinking peers. Conclusions: Four trajectory classes were observed and were best predicted by a combination of items that refl ected demography, substance use, level of response and externalizing phenotypes, and baseline environment and attitudes. (J. Stud. Alcohol Drugs, 75, 24-34, 2014)

A Preliminary Prospective Study of an Escalation in ‘Maximum Daily Drinks’, Fronto-Parietal Circuitry and Impulsivity-Related Domains in Young Adult Drinkers

“…For the purposes of this preliminary study, high MaxDrinks was defined as three or more drinks in excess of NIAAA guidelines for binge drinking episodes (NIAAA, 2004); ie, individuals with a baseline MaxDrinks of 7+ for females and 8+ for males were excluded from analyses. Consistent with previous reports (Schuckit et al, 2014), the high MaxDrinks individuals averaged three times the MaxDrinks relative to non-high MaxDrinks participants (MaxDrinks (SD) = 10.3 (3.2) and 3.1 (2.1), respectively) and averaged a decrease in MaxDrinks (average change = − 2.6 (4.2) drinks) during follow-up. Of those excluded for insufficient follow-up reports, baseline interviews indicated over half would have been excluded from analyses for no history of alcohol use (N = 7) or a high baseline MaxDrinks (N = 25).…”

“…To address hypotheses related to prospective increases in MaxDrinks in young adult drinkers, individuals were excluded if they reported no lifetime drinking (N = 17) or did not complete at least one monthly report of alcohol use every quarter for the 12-month period following fMRI (N = 49). Additional participants were excluded for a high baseline MaxDrinks (N = 12) as individuals exhibiting a high MaxDrinks in early adulthood follow different MaxDrinks trajectories than their peers (Schuckit et al, 2014). For the purposes of this preliminary study, high MaxDrinks was defined as three or more drinks in excess of NIAAA guidelines for binge drinking episodes (NIAAA, 2004); ie, individuals with a baseline MaxDrinks of 7+ for females and 8+ for males were excluded from analyses.…”

“…Sample sizes limited the ability to investigate potential influences of multiple factors that may be associated with escalating-drinking, including gender, socioeconomic status, and pubertal timing, or investigate mutliple trajectories of MaxDrinks through young adulthood (Schuckit et al, 2014). Although baseline and prospectivedrinking categories were defined using convenience criteria relative to MaxDrinks, escalating drinkers relative to constant drinkers displayed increases in non-MaxDrinksrelated frequency of alcohol use (ie, months of drinking and days drinking per month).…”

“…The maximum number of drinks consumed on a single occasion ('MaxDrinks') is linked to the development of AUDs and may represent a reliable phenotype for identifying individuals at risk for AUDs (Grant et al, 2009;Saccone et al, 2000). An increase in the daily quantity consumed over time, or an 'escalation' in MaxDrinks, during early adulthood may further be indicative of a greater risk for developing AUDs (Auerbach and Collins, 2006;Schuckit et al, 2014). Investigating neurobiological and impulsivity-related features associated with an escalation in MaxDrinks in early adulthood may help identify vulnerable populations and inform prevention and intervention strategies.…”

Latent Trajectory Classes for Alcohol‐Related Blackouts from Age 15 to 19 in ALSPAC

“…Regarding the appropriate number of classes, this process was guided by criteria that if another class was added: the Bootstrap Likelihood Ratio Test (BLRT) became noncontributory; and/or the Bayesian Information Criterion (BIC) stopped decreasing; and that the classes became difficult to interpret (Jung and Wickrama, 2008; Nagin and Tremblay, 2001; Schwartz, 1978). Next, consistent with a recent report (Schuckit et al, 2014), baseline characteristics were used as predictors of class membership, rather than as covariates, by evaluating differences in predictors across latent trajectory classes using chi square (χ 2 ) and ANOVA in a process carried out outside the LCGA. Finally, baseline items that were different across classes were entered into a simultaneous entry multinomial logistic regression analysis, with continuous items z-scored to facilitate comparisons of odds ratios (ORs) across items.…”