Ryan S. Trim

The Relationships of the Level of Response to Alcohol and Additional Characteristics to Alcohol Use Disorders Across Adulthood: A Discrete-Time Survival Analysis

BACKGROUND A low level of response (LR) to alcohol has been shown to relate to a higher risk for alcohol use disorders (AUDs). However, no previous research has examined the association between LR and the development of AUDs in the context of additional robust risk factors for AUDs. This study evaluated whether LR and other related characteristics predicted the occurrence of AUDs across adulthood using discrete-time survival analysis (DTSA). METHODS A total of 297 probands from the San Diego Prospective Study reported on the LR to alcohol, a family history (FH) of AUDs, the typical drinking quantity, the age of drinking onset, the body mass index and the age at the baseline (T1) assessment. Alcohol use disorders (AUDs) were evaluated at the 10-year (T10), T15, T20, and T25 follow-ups. RESULTS A low LR to alcohol predicted AUD occurrence over the course of adulthood even after controlling for the effects of other robust risk factors. Interaction effects revealed that the impact of FH on AUDs was only observed for subjects with high T1 drinking levels, and probands with high T1 drinking were at high risk for AUDs regardless of their age of onset. CONCLUSIONS The findings illustrate that LR is a unique risk factor for AUDs across adulthood, and not simply a reflection of a broader range of risk factors. The continued investigation of how LR is related to AUD onset later in life will help inform treatment providers about this high-risk population, and future longitudinal evaluations will utilize DTSA to assess rates of AUD remission as well as the onset of drinking outcomes in adolescent samples.

White Matter Integrity, Substance Use, and Risk Taking in Adolescence

White matter development is important for efficient communication between brain regions, higher order cognitive functioning, and complex behaviors. Adolescents have a higher propensity for engaging in risky behaviors, yet few studies have explored associations between white matter integrity and risk taking directly. Altered white matter integrity in mid-adolescence was hypothesized to predict subsequent risk taking behaviors 1.5 years later. Adolescent substance users (predominantly alcohol and marijuana, n = 47) and demographically similar nonusers (n = 49) received diffusion tensor imaging at baseline (ages 16-19), and risk taking measures at both baseline and an 18-month follow-up (i.e., at ages 17-20). Brain regions of interest were the fornix, superior corona radiata, superior longitudinal fasciculus, and superior fronto-occipital fasciculus. In substance-using youth (n = 47), lower white matter integrity at baseline in the fornix and superior corona radiata predicted follow-up substance use (ΔR2 = 10-12%, ps < .01), and baseline fornix integrity predicted follow-up delinquent behaviors (ΔR2 = 10%, p < .01) 1.5 years later. Poorer fronto-limbic white matter integrity was linked to a greater propensity for future risk taking behaviors among youth who initiated heavy substance use by mid-adolescence. Most notable were relationships between projection and limbic-system fibers and future substance-use frequency. Subcortical white matter coherence, along with an imbalance between the maturation levels in cognitive control and reward systems, may disadvantage the resistance to engage in risk taking behaviors during adolescence.

Blood alcohol concentrations among bar patrons: A multi-level study of drinking behavior.

This paper presents data from a study that collected observational data, survey data, and breath samples to estimate blood alcohol concentrations (BrAC) from patrons attending 30 bars. The study examines: (1) drinking behavior and settings prior to going to a bar; (2) characteristics of the bar where respondents are drinking; (3) person and environmental predictors of BrAC change (entrance to exit). Purposive sampling of bars that cater to young adults gave a sample of 30 bars. Patrons were randomly selected from bars (n=839). Approximately half of the sample was female (48.7%). Nearly three-quarters of participants reported drinking before attending the bar. Serving practices of the bars were observed; majority of bars served excessive amounts of alcohol in short periods of time. On average, those who drank before attending the bar had BrACs at approximately half the legal limit. Implications for responsible beverage service coupled with law enforcement strategies are discussed.

The relation between adolescent substance use and young adult internalizing symptoms: findings from a high-risk longitudinal sample.

The present study examined the role of adolescent substance use and its antecedent behavioral and familial risk factors in the prediction of young adult internalizing symptoms 10 years later, using a community sample of children of alcoholics (n = 194) and demographically matched controls (n = 209). Using growth curve modeling, the authors found that initial levels of adolescent alcohol and drug use (mu-sub(age) = 13) and growth in drug use during adolescence predicted higher levels of internalizing symptoms in young adulthood, even after including in the models shared risk factors for both internalizing symptoms and adolescent substance use. These effects remained significant after including concurrent substance use in adulthood, suggesting that adolescent substance use exerts a long-term impact on young adult internalizing symptoms over and above the effects of persistent substance use over time. The present investigation further revealed that initial levels of alcohol and drug use in adolescence mediate the relation between parental alcoholism and young adult internalizing symptoms. Findings provide evidence for the long-term effects of adolescent substance use on young adult functioning and can help inform both etiological and prevention research.

A prospective study of the Acquired Preparedness Model: the effects of impulsivity and expectancies on smoking initiation in college students.

This study reports on a prospective test of the Acquired Preparedness Model, which posits that impulsivity influences cigarette smoking through the formation of more positive and fewer negative expectancies about smoking effects. College freshman never-smokers (n = 400; 45% male) completed a baseline interview and quarterly online follow-up assessments for 15 months after baseline. Structural equation modeling indicated that the effects of the impulsivity components of sensation seeking and negative urgency on risk of smoking initiation were mediated by expectancies for positive and negative reinforcement from smoking, respectively. Expectancies about negative consequences from smoking predicted initiation but did not mediate the effects of sensation seeking or negative urgency. Findings are consistent with the Acquired Preparedness Model and suggest that heightened impulsivity is associated with heightened expectancies for reinforcement from smoking, and thus with greater risk for smoking initiation.

The Prognostic Implications of DSM-IV Abuse Criteria in Drinking Adolescents

BACKGROUND The validity of the DSM-IV diagnostic criteria for alcohol abuse has been questioned, and additional issues have been raised regarding the performance of this label in adolescents. While future diagnostic manuals might alter the approach to abuse, it is worthwhile to evaluate the implications of the current definition that has been in place since 1994. METHODS Six hundred and sixteen 12-19-year-old subjects (mean 16.5 years) were offspring identified in the Collaborative Study on the Genetics of Alcoholism (COGA) protocol who had ever consumed a full drink and who were followed up 5 years later using age-appropriate semi-structured interviews. Following the guidelines for evaluating the utility of the diagnostic labels of Robins and Guze [Robins, E., Guze, S.B., 1970. Establishment of diagnostic validity in psychiatric illness: its application to schizophrenia. Am. J. Psychiat. 126, 983-987], the subjects with alcohol abuse were compared with other groups regarding clinical validators and clinical course. RESULTS At initial interview, the pattern of most alcohol use and problem variables were least severe for teenagers with no diagnosis, intermediate for those with abuse, and the highest for individuals with alcohol dependence. At follow-up, 50% of those with initial abuse maintained that diagnosis, 19% developed dependence, and 31% had no DSM-IV diagnosis. Baseline alcohol abuse predicted follow-up diagnosis even when evaluated along with initial demographic and substance use characteristics. CONCLUSIONS These results support some assets for the DSM-IV alcohol abuse criteria in these adolescents, including indications of both cross-sectional and predictive validities. Additional studies will need to compare the current abuse label with other possible approaches.

The Self-Rating of the Effects of Alcohol Questionnaire as a Predictor of Alcohol-Related Outcomes in 12-Year-Old Subjects

AIMS A low level of response (LR), or low sensitivity, to alcohol as established by alcohol challenges has been shown to predict future heavier drinking, alcohol-related problems and alcohol use disorders. To date, only one study has evaluated the predictive validity of a second measure of LR as determined by the Self-Report of the Effects of Alcohol (SRE) Questionnaire. The current analyses evaluate the ability of SRE scores as determined at age 12 to predict heavier drinking and alcohol-related problems 2 years later in a sample from the United Kingdom. METHODS The subjects were 156 boys (54.5%) and girls from the Avon Longitudinal Study of Parents and Children (ALSPAC) who had reported consuming one or more standard drinks by age 12 and who were followed up 2 years later. RESULTS The age 12 SRE scores correlated with the number of drinks per week, maximum drinks and the number of alcohol problems both at baseline and at age 14 follow-ups. In these evaluations, a larger number of drinks required for effects on the SRE (i.e. a lower LR per drink consumed) related to heavier intake and alcohol-related difficulties. Simultaneous entry multiple regression analyses revealed that the age 12 SRE score maintained a significant relationship with age 14 higher number of drinks per week and the number of alcohol problems even when the age 12 values for alcohol intake and problems were used as covariates. CONCLUSION The SRE scores appear to have value in predicting future heavier drinking and alcohol problems in 12-year olds that go beyond the information offered by the earlier drinking pattern alone.

Thinking and drinking: alcohol-related cognitions across stages of adolescent alcohol involvement.

Alcohol-related cognitions, particularly expectancies for drinking and nondrinking and motives for nondrinking, are involved in the initiation, maintenance, and cessation of alcohol use and are hypothesized to play key roles in adolescent decision making. This study explored (a) the relationships between alcohol use expectancies, nondrinking expectancies, and nondrinking motives; (b) the roles of these cognitions across hypothesized developmental stages of adolescent alcohol use; and (c) the relationships between these cognitions and recent or intended future changes in drinking behavior in a cross-sectional sample. Surveys assessing alcohol use behaviors and attitudes were administered to 1,648 high school students. Heavier drinkers reported more positive alcohol use expectancies and fewer nondrinking motives than did lighter drinkers or nondrinkers; however, nondrinking expectancies only differed between nondrinkers and rare drinkers and all subsequent drinking classes. Alcohol use expectancies, nondrinking expectancies, and nondrinking motives differentiated students who recently initiated alcohol from those who had not, while nondrinking expectancies and nondrinking motives differentiated binge-drinking students who had made recent efforts to reduce/stop their drinking from those who had not. Intentions to initiate or reduce drinking in the coming month were also associated with these alcohol-related cognitions. Drinking and nondrinking expectancies and motives for not drinking may play critical roles in decisions to alter alcohol-use behavior during adolescence. Future exploration of temporal relationships between changes in alcohol-related cognitions and behavioral decision making will be useful in the refinement of effective prevention and intervention strategies.

The Overlap in Predicting Alcohol Outcome for Two Measures of the Level of Response to Alcohol

BACKGROUND Two different measures have been used to establish a persons level of response (LR) to alcohol as a risk factor for alcohol use disorders. LR values established by the alcohol challenge protocol and the Self-Report of the Effects of Ethanol (SRE) questionnaire usually correlate at 0.3 to 0.4, up to 0.6. However, it is not clear how this correlation relates to the ability of each measure to predict alcohol outcomes. This paper evaluates that overlap. METHODS Sixty-six Caucasian males (mean age = 22 years) from 2 protocols participated in alcohol challenges with 0.75 ml/kg of ethanol, filled out the SRE, and were followed with a structured interview approximately 5 years later. The relationship between the subjective feelings of intoxication at the time of peak breath alcohol levels from the alcohol challenge and the SRE score for a time early in the drinking career were evaluated regarding predicting the drinks per occasion in the 6 months prior to follow-up. RESULTS Cross-sectional correlations between alcohol challenge and SRE LRs ranged from -0.25 (p < 0.05) to -0.32 (p = 0.02) for the full sample, and the 2 LR measures correlated with drinking at follow-up (-0.26 and 0.41, respectively). The SRE measure was more robust than the challenge in a regression analysis predicting the outcome in the context of other baseline predictors (e.g., drinking at baseline). As much as 60% of the ability of the more well established (gold standard) alcohol challenge LR to predict outcome was shared with the SRE. The alcohol challenge accounted for as much as 44% of the ability of the SRE to predict outcome. CONCLUSIONS The SRE-generated LR overlapped considerably with the alcohol challenge LR in the ability to predict future heavier drinking.

fMRI Differences Between Subjects with Low and High Responses to Alcohol During a Stop Signal Task

BACKGROUND A low level of response (i.e., a low LR) to alcohol is a genetically influenced phenotype that predicts later alcoholism. While the low LR reflects, at least in part, a low brain response to alcohol, the physiological underpinnings of the low LR have only recently been addressed. METHODS Forty-nine drinking but not yet alcoholic matched pairs of 18- to 25-year-old subjects (N = 98; 53% women) with low and high LRs as established in separate alcohol challenges were evaluated in 2 event-related functional magnetic resonance imaging (fMRI) sessions (placebo and approximately 0.7 ml/kg of alcohol) while performing a validated stop signal task. The high and low LR groups had identical blood alcohol levels during the alcohol session. RESULTS Significant high versus low LR group and LR group × condition effects were observed in blood oxygen level-dependent (BOLD) signal during error and inhibitory processing, despite similar LR group performance on the task. In most clusters with significant (corrected p < 0.05, clusters > 1,344 μl) LR group × alcohol/placebo condition interactions, the low LR group demonstrated relatively less, whereas the high LR group demonstrated more, error and inhibition-related activation after alcohol compared with placebo. CONCLUSIONS This is one of the first fMRI studies to demonstrate significant differences between healthy groups with different risks of a future life-threatening disorder. The results may suggest a brain mechanism that contributes to how a low LR might enhance the risk of future heavy drinking and alcohol dependence.