Eun Young Mun

A model-based cluster analysis approach to adolescent problem behaviors and young adult outcomes

Data from a community-based sample of 1,126 10th- and 11th-grade adolescents were analyzed using a model-based cluster analysis approach to empirically identify heterogeneous adolescent subpopulations from the person-oriented and pattern-oriented perspectives. The model-based cluster analysis is a new clustering procedure to investigate population heterogeneity utilizing finite mixture multivariate normal densities and accordingly to classify subpopulations using more rigorous statistical procedures for the comparison of alternative models. Four cluster groups were identified and labeled multiproblem high-risk, smoking high-risk, normative, and low-risk groups. The multiproblem high risk exhibited a constellation of high levels of problem behaviors, including delinquent and sexual behaviors, multiple illicit substance use, and depressive symptoms at age 16. They had risky temperamental attributes and lower academic functioning and educational expectations at age 15.5 and, subsequently, at age 24 completed fewer years of education, and reported lower levels of physical health and higher levels of continued involvement in substance use and abuse. The smoking high-risk group was also found to be at risk for poorer functioning in young adulthood, compared to the low-risk group. The normative and the low risk groups were, by and large, similar in their adolescent and young adult functioning. The continuity and comorbidity path from middle adolescence to young adulthood may be aided and abetted by chronic as well as episodic substance use by adolescents.

Associations Between Heavy Drinking and Changes in Impulsive Behavior Among Adolescent Boys

BACKGROUND Impulsive behavior in humans predicts the onset of drinking during adolescence and alcohol use disorders (AUDs) in adulthood. It is also possible, however, that heavy drinking may increase impulsive behavior by affecting the development of brain areas that support behavioral control or through other associated mechanisms. This study examined whether drinking heavily during adolescence is related to changes in impulsive behavior with a specific focus on how the association differs across individuals, contingent on the developmental course of their impulsiveness. METHOD Data came from a sample of boys (N = 503) who were followed annually from approximate age 8 to age 18 and again at approximate age 24/25. Heavy drinking was defined as experiencing a blood alcohol concentration (BAC) level of 0.08% or higher. At each assessment, the parent and child each reported whether the child was impulsive. RESULTS First, group-based trajectory analysis was used to identify 4 groups differing in the level and slopes of their trajectories of impulsive behavior from age 9 to age 17: low (13.9%), early adolescence-limited (18.7%), moderate (60.8%), and high (6.6%). These trajectory groups differed in their prevalence of any heavy drinking, peak BACs, and rates of alcohol dependence in adolescence and AUD in early adulthood, with the less impulsive groups being lower on these measures than the more impulsive groups. Heavy drinking was then entered into the model as a time-varying covariate; this measure was lagged so that the results represent change in impulsive behavior the year following heavy drinking. Among boys on the moderate trajectory, those who drank heavily were rated as significantly more impulsive the following year compared to those who did not drink heavily. CONCLUSIONS The association between heavy drinking and impulsive behavior may depend on earlier levels of impulsive behavior with those who are moderately impulsive appearing to be at greatest risk for increased impulsive behavior following heavy drinking. Further research is needed to clarify this association.

Heart rate variability response to alcohol, placebo, and emotional picture cue challenges: effects of 0.1-Hz stimulation.

Heart rate variability (HRV) supports emotion regulation and is reduced by alcohol. Based on the resonance properties of the cardiovascular system, a new 0.1-Hz methodology was developed to present emotional stimuli and assess HRV reaction in participants (N=36) randomly assigned to an alcohol, placebo, or control condition. Blocked picture cues (negative, positive, neutral) were presented at a rate of 5 s on, 5 s off (i.e., 0.1-Hz frequency). SDNN, pNN50, and HF HRV were reduced by alcohol, compared to the placebo and control. The 0.1-Hz HRV index was diminished by alcohol and placebo, suggesting that autonomic regulation can be affected by cognitive expectancy. The 0.1-Hz HRV index and pNN50 detected changes in arousal during emotional compared to neutral cues, and the 0.1-Hz HRV index was most sensitive to negative valence. The 0.1-Hz HRV methodology may be useful for studying the intersection of cognition, emotion, and autonomic regulation.

Do Brief Personalized Feedback Interventions Work for Mandated Students or Is It Just Getting Caught That Works

Studies evaluating the efficacy of brief interventions with mandated college students have reported declines in drinking from baseline to short-term follow-up regardless of intervention condition. A key question is whether these observed changes are due to the intervention or to the incident and/or reprimand. This study evaluates a brief personalized feedback intervention (PFI) for students (N = 230) who were referred to a student assistance program because of infractions of university rules regarding substance use to determine whether observed changes in substance use are attributable to the intervention. Half the students received immediate feedback (at baseline and after the 2-month follow-up), and half received delayed feedback (only after the 2-month follow-up). Students in both conditions generally reduced their drinking and alcohol-related problems from baseline to the 2-month follow-up and from the 2-month to the 7-month follow-up; however, there were no significant between-group differences at either follow-up. Therefore, it appears that the incident and/or reprimand are important instigators of mandated student change and that written PFIs do not enhance these effects on a short-term basis but may on a longer term basis.

Finding groups using model-based cluster analysis: heterogeneous emotional self-regulatory processes and heavy alcohol use risk.

Model-based cluster analysis is a new clustering procedure to investigate population heterogeneity utilizing finite mixture multivariate normal densities. It is an inferentially based, statistically principled procedure that allows comparison of nonnested models using the Bayesian information criterion to compare multiple models and identify the optimum number of clusters. The current study clustered 36 young men and women on the basis of their baseline heart rate and heart rate variability (HRV), chronic alcohol use, and reasons for drinking. Two cluster groups were identified and labeled the high alcohol risk and normative groups. Compared to the normative group, individuals in the high alcohol risk group had higher levels of alcohol use and more strongly endorsed disinhibition and suppression reasons for use. The high alcohol risk group showed significant HRV changes in response to positive and negative emotional and appetitive picture cues, compared to neutral cues. In contrast, the normative group showed a significant HRV change only to negative cues. Findings suggest that individuals with autonomic self-regulatory difficulties may be more susceptible to heavy alcohol use and use of alcohol for emotional regulation.

Moderators of the dynamic link between alcohol use and aggressive behavior among adolescent males.

Although longitudinal evidence has linked alcohol use with aggressive behavior during adolescence, most studies have failed to adequately control for the numerous between-individual differences that may underlie this association. In addition, few studies of adolescents have examined whether the nature of the within-individual association between alcohol use and aggression depends on individual and contextual factors. To address these limitations, this study examined the association between within-individual changes in alcohol use and aggressive behavior across adolescence and determined whether impulsive behavior, positive attitudes toward violence, violent peers, neighborhood crime, and race moderated this association. Data from 971 adolescent males assessed annually from ages 13 to 18 were analyzed using a within-individual regression panel model that eliminated all stable between-individual factors as potential confounds. Findings indicated that within-individual increases in alcohol use quantity from one’s own typical levels of drinking were concurrently associated with within-individual increases in aggressive behavior, and vice versa. However, increases in alcohol were more strongly linked to increases in aggressive behavior among boys with attitudes favoring violence and those who lived in high-crime neighborhoods. The association between alcohol and aggressive behavior was similar for White and Black young men. Interventions designed to reduce aggressive behaviors should consider targeting not only alcohol use, but also individual and environmental risk factors that contribute to this link.

Racial differences in trajectories of heavy drinking and regular marijuana use from ages 13 to 24 among African-American and White males

BACKGROUND Although there are significant differences in prevalence of substance use between African-American and White adolescents, few studies have examined racial differences in developmental patterns of substance use, especially during the important developmental transition from adolescence to young adulthood. This study examines racial differences in trajectories of heavy drinking and regular marijuana use from adolescence into young adulthood. METHODS A community-based sample of non-Hispanic African-American (n=276) and non-Hispanic White (n=211) males was analyzed to identify trajectories from ages 13 to 24. RESULTS Initial analyses indicated race differences in heavy drinking and regular marijuana use trajectories. African Americans were more likely than Whites to be members of the nonheavy drinkers/nondrinkers group and less likely to be members of the early-onset heavy drinkers group. The former were also more likely than the latter to be members of the late-onset regular marijuana use group. Separate analyses by race indicated differences in heavy drinking for African Americans and Whites. A 2-group model for heavy drinking fit best for African Americans, whereas a 4-group solution fit best for Whites. For regular marijuana use, a similar 4-group solution fit for both races, although group proportions differed. CONCLUSIONS Within-race analyses indicated that there were clear race differences in the long-term patterns of alcohol use; regular marijuana use patterns were more similar. Extended follow ups are needed to examine differences and similarities in maturation processes for African-American and White males. For both races, prevention and intervention efforts are necessary into young adulthood.

Individual and situational factors that influence the efficacy of personalized feedback substance use interventions for mandated college students.

Little is known about individual and situational factors that moderate the efficacy of personalized feedback interventions (PFIs). Mandated college students (N = 348) were randomly assigned either to a PFI delivered in the context of a brief motivational interview (BMI; n = 180) or to a written PFI only (WF) condition and were followed up at 4 months and 15 months postintervention. The authors empirically identified heterogeneous subgroups utilizing mixture modeling analysis based on heavy episodic drinking and alcohol-related problems. The 4 identified groups were dichotomized into an improved group (53.4%) and a nonimproved group (46.6%). Logistic regression results indicated that the BMI was no more efficacious than the WF across all mandated students. However, mandated students who experienced a serious incident requiring medical or police attention and those with higher levels of alcohol-related problems at baseline benefited more from the BMI than from the WF. It may be an efficacious and cost-effective approach to provide a written PFI for low-risk mandated students and an enhanced PFI with a BMI for those students who experience a serious incident or have higher baseline alcohol-related problems.

Effects of Institutional Confinement for Delinquency on Levels of Depression and Anxiety among Male Adolescents.

Youths within the juvenile justice system report higher rates of mental illnesses than their peers. This study tested whether institutional confinement increases levels of depression and anxiety among male adolescents. The authors examined heterogeneous trajectories of depression and anxiety from ages 11 to 14 years for 510 male adolescents. Youths who were first placed in custody at age 15 (treatment group) were matched with control boys (no official arrest or reported confinement during adolescence) within each trajectory group using a propensity score (PS) matching procedure. Matches were found for 37 pairs for depression and 34 pairs for anxiety. There were no significant differences between the confined and control groups in levels of depression or anxiety at age 16. More research is needed to identify aspects of the juvenile justice system, which may positively or negatively affect youth’s mental health status.

Racial differences in the consequences of childhood maltreatment for adolescent and young adult depression, heavy drinking, and violence.

PURPOSE This study examined racial differences in the consequences of childhood maltreatment for depression, heavy drinking, and violence during adolescence and young adulthood among black and white young men. METHODS Data were obtained from the Pittsburgh Youth Study, a prospective longitudinal study of urban males (N = 971, 56% black). Childhood maltreatment was defined as substantiated physical or sexual abuse, physical neglect, emotional maltreatment, or moral/legal/educational maltreatment, with the first referral before 12 years of age. Self-reports of depressive symptoms and heavy drinking (consuming more than six drinks on a single occasion) and official, parent, and self-reports of violent offending were assessed between 12 and 17 years of age (adolescence) and at 24/25 years of age (young adulthood). Regression analyses were conducted to examine childhood maltreatment and race, as well as maltreatment-by-race interactions, as predictors of the three outcomes. RESULTS Prevalence of childhood maltreatment was higher for black than for white boys; however, there were no racial differences in timing, type, severity, and chronicity of maltreatment. When socioeconomic status and cohort were controlled, childhood maltreatment significantly predicted depressive symptoms and violence in adolescence but none of the outcomes in young adulthood. Race was a significant predictor of heavy drinking and violence during adolescence, and of all three outcomes in young adulthood. No significant race-by-maltreatment interaction effects were found. CONCLUSIONS Childhood maltreatment has similar negative consequences for black and white male youth during adolescence. Extending intervention efforts through adolescence is important to alleviate these problems among victims.