Robert D. Dvorak

Moderation of Resource Depletion in the Self-Control Strength Model: Differing Effects of Two Modes of Self-Control

The current study examined the effects of good and poor control and changes in blood glucose following self-control depletion on task persistence. Good self-control attenuated the effect of depletion on task persistence. Poor control exerted a main effect; however, there were no significant interactions between poor control and self-control depletion. In addition, the association between depletion and task persistence was partially mediated by decreases in blood glucose. Task persistence in the experimental, but not control, condition was correlated with several risk behaviors. These correlations provide support for the external validity of the laboratory experiment. The differential effects of good and poor control support a two-mode model of self-control. The interaction between the depletion manipulation and good self-control suggests that associations between good self-control and behavior may be due, in part, to good self-control reducing the effects of self-control demands on behavior.

Event-level associations between affect, alcohol intoxication, and acute dependence symptoms: Effects of urgency, self-control, and drinking experience

This study used experience sampling to examine within-person associations between positive affect, anxiety, sadness, and hostility and two outcomes: alcohol intoxication and acute dependence symptoms. We examined the role of urgency, premeditation, and perseverance in predicting the alcohol outcomes and tested whether the affective associations varied as a function of urgency. Participants completed baseline assessments and 21 days of experience sampling on PDAs. Hypotheses were partially confirmed. Positive affect was positively, and sadness inversely, associated with intoxication. Hostility was associated with intoxication for men but not women. Negative urgency moderated the association between anxiety and intoxication, making it stronger. However, positive urgency did not moderate the effect of positive affect. Heavier drinkers exhibited the greatest number of symptoms, yet the association between intoxication and acute signs of alcohol disorder was attenuated among these individuals. Results support the use of experience sampling to study acute signs and symptoms of high risk drinking and dependence.

Behavioral Inhibition and Activation Systems: Differences in Substance Use Expectancy Organization and Activation in Memory

We used multidimensional scaling to model the semantic network of alcohol and marijuana expectancies (N=897). Preference mapping was used to estimate vectors representing patterns of activation through the network as a function of levels of behavioral inhibition (BIS) and behavioral activation (BAS). Individuals with low BIS combined with high BAS levels exhibited patterns of activation emphasizing behavioral activation similar to heavier drug users in previous research. High BIS, low BAS individuals exhibited activation patterns with greater emphasis on inhibitory expectancies similar to low-level users. Differences in expectancy activation patterns were maintained after controlling for substance use and gender. Individual differences in BIS/BAS are associated with the organization of semantic networks and patterns of activation of expectancies contributing to differences in substance use behavior.

Methamphetamine Use in a Rural College Population: Associations With Marijuana Use, Sensitivity to Punishment, and Sensitivity to Reward

This study examined predictors of methamphetamine use in a 6-month prospective study of 2,270 rural young adults. Sensitivity to punishment (SP), sensitivity to reward (SR), and gender were exogenous variables in an observed variable path analysis with 3 endogenous criteria: Time 1 (T1) marijuana use and methamphetamine use at T1 and Time 2 (T2). SP was negatively associated with marijuana use at T1, and this association was attenuated by SR. Male gender was positively associated with marijuana use. T1 marijuana use and SR were positively, and male gender negatively, associated with T1 methamphetamine use. T1 methamphetamine use, T1 marijuana use, and SP were positively associated with T2 methamphetamine use. Methamphetamine use prevalence and the role of distal predictors and proximal indicators of drug involvement are discussed.

Dimensions and severity of marijuana consequences: Development and validation of the Marijuana Consequences Questionnaire (MACQ)

The Marijuana Consequences Questionnaire (MACQ) is a 50-item self-report measure modeled after the Young Adult Alcohol Consequences Questionnaire (YAACQ). College students (n=315) completed questionnaires online. A confirmatory factor analysis supported the hypothesized 8-factor structure. The results indicate good convergent and discriminant validity of the MACQ. A brief, unidimensional, 21-item version (B-MACQ) was developed by a Rasch model. Comparison of item severity estimates of the B-MACQ items and the corresponding items from the YAACQ indicates that the severity of alcohol- and marijuana-problems is defined by a relatively unique pattern of consequences. The MACQ and B-MACQ provide promising new alternatives to assessing marijuana-related problems.

Alcohol-Related Infractions among College Students: Associations with Subsequent Drinking as a Function of Sensitivity to Punishment

Problematic alcohol use on college campuses is a significant concern. Violations of campus alcohol policies can lead to disciplinary action from the university. These and other alcohol-related legal infractions may be a sign of significant alcohol-related problems. However, few studies have focused on determining predictors of alcohol-related infractions among college students. Likewise, the role of infractions in reducing future use is unclear. In the present study, we tested whether alcohol-related infractions were associated with decreased alcohol use, and whether the effect of the infraction varied as a function of initial drinking levels, sensitivity to punishment (SP), and sensitivity to reward (SR) in a 6-month prospective design. Alcohol use, grade point average, and SR were significantly associated with receiving an alcohol-related infraction. For heavier drinkers, receiving an infraction was associated with decreased drinking at follow-up, and this decrease was most pronounced among those with higher sensitivity to punishment. SP appeared to increase responsiveness to the infraction, resulting in greater attenuation of drinking at follow-up.

Impulsivity moderates the association between depressive rumination and number of quit attempt failures by smokers

Negative mood states have been shown to increase the likelihood of relapse among smokers attempting to quit. Rumination increases the vulnerability to depression among smokers, a relationship that is intensified by impulsivity. This cross-sectional study investigated the association between depressive rumination and impulsivity on smokers’ (n = 53) lifetime quit attempt failures. Depressive rumination was positively associated with number of quit attempt failures. As hypothesized, there was a significant interaction between depressive rumination and impulsivity. At high levels of impulsivity, there was a strong positive association between depressive rumination and number of quit attempt failures. However, at low levels of impulsivity the association between depressive rumination and quit attempt failures was diminished and not significant. The results support an affect regulation model of quit attempt failures, whereby impulsivity strengthens effects of depressive rumination, decreasing the likelihood of successfully quitting smoking.

Tobacco use and body mass index: mediated effects through physical inactivity.

The current study examined associations between smoking and body mass index (BMI) utilizing a nationally representative sample of adults (N = 1547). Previous research has shown that smokers have lower BMI than non-smokers; however among smokers, tobacco use is positively associated with BMI. Previous authors have hypothesized this is due to poor behavioral habits among smokers. Building on this, we found that smoking was positively associated with physical inactivity, which mediated the association between tobacco use and BMI. Interpretation, limitations, and future directions are discussed.