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1.  A Human Alcohol Self-Administration Paradigm to Model Individual Differences in Impaired Control over Alcohol Use 
We developed an alcohol self-administration paradigm to model individual differences in impaired control. The paradigm includes moderate drinking guidelines meant to model limits on alcohol consumption, which are typically exceeded by people with impaired control. Possible payment reductions provided a disincentive for excessive drinking. Alcohol use above the guideline, despite possible pay reductions, was considered to be indicative of impaired control. Heavy-drinking 21–25 year-olds (N = 39) were randomized to an experimental condition including the elements of the impaired control paradigm or to a free-drinking condition without these elements. Alcohol self-administration was compared between these two conditions to establish the internal validity of the experimental paradigm. In both conditions, participants self-administered beer and non-alcoholic beverages for 3 hours in a bar setting with 1–3 other participants. Experimental condition participants self-administered significantly fewer beers and drank to lower blood-alcohol concentrations (BACs) on average than those in the free-drinking condition. Experimental condition participants were more likely than free-drinking condition participants to intersperse non-alcoholic beverages with beer and to drink at a slower pace. Although experimental condition participants drank more moderately than those in the free-drinking condition overall, their range of drinking was considerable (BAC range = .024–.097) with several participants drinking excessively. A lower initial subjective response to alcohol and earlier age of alcohol use onset were associated with greater alcohol self-administration in the experimental condition. Given the variability in response, the impaired control laboratory paradigm may have utility for preliminary tests of novel interventions in future studies and for identifying individual differences in problem-drinking risk.
PMCID: PMC4131292  PMID: 23937598
laboratory methods; young adult; negative consequences; protective strategies; subjective response
2.  Perceived parental permissiveness toward gambling and risky behaviors in adolescents 
Journal of Behavioral Addictions  2014;3(2):115-123.
Background and aims: Perceived parental permissiveness toward gambling may relate to adolescents’ engagement in various risky behaviors. To examine this possibility, we analyzed data from a high-school based risk-behavior survey to assess relationships between perceived parental permissiveness toward gambling and adolescent gambling behavior, substance use and related problems. We also evaluated predictions that relationships between perceived parental permissiveness toward gambling and risky behaviors would be particularly strong amongst adolescents reporting high sensation-seeking or impulsivity. Methods: High-school students (n = 2,805) provided data on risky behaviors, perceived parental permissiveness toward gambling, impulsivity and sensation-seeking. Bivariate and logistic regression analyses were conducted to examine relationships with gambling and alcohol, cigarette and marijuana use. Results: Perceived parental permissiveness toward gambling related significantly to adolescent gambling, all substance-use behaviors as well as alcohol and drug problems. There were significant parental-permissiveness-by-sensation-seeking interactions in multiple models. Relationships between perceived parental permissiveness toward gambling and alcohol-use frequency were particularly strong among those with high sensation-seeking. This relationship also applied to gambling and heavy cigarette smoking, albeit to a lesser extent. Impulsivity related strongly to drug problems among those who perceived their parents to be more and less permissive toward gambling. Discussion and conclusions: These findings support the relevance of perceived parental permissiveness toward gambling to adolescent risky behaviors. Parenting perceived as less permissive toward gambling appeared to have protective effects on gambling, alcohol and cigarette use, even among those with high sensation-seeking. Reducing parental permissiveness toward gambling may be a valuable intervention goal, particularly for parents of sensation-seeking adolescents.
PMCID: PMC4117283  PMID: 25215222
alcohol; cigarette; impulsivity; marijuana; sensation seeking; smoking
3.  A Targeted Review of the Neurobiology and Genetics of Behavioral Addictions: An Emerging Area of Research 
This review summarizes neurobiological and genetic findings in behavioral addictions, draws parallels with findings pertaining to substance use disorders and offers suggestions for future research. Articles concerning brain function, neurotransmitter activity and family history/genetics findings for behavioral addictions involving gambling, internet use, video game playing, shopping, kleptomania and sexual activity were reviewed. Behavioral addictions involve dysfunction in several brain regions, particularly the frontal cortex and striatum. Findings from imaging studies incorporating cognitive tasks have arguably been more consistent than cue-induction studies. Early results suggest white and gray matter differences. Neurochemical findings suggest roles for dopaminergic and serotonergic systems, but results from clinical trials seem more equivocal. While limited, family history/genetic data support heritability for pathological gambling and that those with behavioral addictions are more likely to have a close family member with some form of psychopathology. Parallels exist between neurobiological and genetic/family history findings in substance and non-substance addictions, suggesting that compulsive engagement in these behaviors may constitute addictions. Findings to date are limited, particularly for shopping, kleptomania and sexual behavior. Genetic understandings are at an early stage. Future research directions are offered.
PMCID: PMC3762982  PMID: 23756286
gambling; internet use; video games; shopping; kleptomania; sexual behavior; neuroimaging; frontal areas; striatum; serotonin
4.  Early Subjective Response and Acquired Tolerance as Predictors of Alcohol Use and Related Problems in a Clinical Sample 
Previous studies have demonstrated that a low subjective response to alcohol is a risk factor for Alcohol Use Disorders (AUDs), and a recent study suggests that acquired tolerance can be differentiated from initial subjective response and is also significantly associated with drinking problems. Because the prior study of subjective response and tolerance focused on a sample of moderate drinkers, the goal of the current study was to examine relations between early subjective response, acquired tolerance, alcohol use, and alcohol-related problems in a sample of young adults with clinically significant alcohol problems.
The current study examined associations between early subjective response and acquired tolerance and both drinking behavior and alcohol-related problems within a sample of 113 heavy drinking young adults (66.1% male) volunteering for a clinical trial of naltrexone in combination with brief motivational counseling.
Consistent with the one prior study examining simultaneous effects of early SR and tolerance, both early subjective response and acquired tolerance were positively associated with typical drinking behavior, though tolerance was a much stronger predictor within this clinical sample. In contrast to the prior study, early subjective response was inversely associated with risk for alcohol-related problems, and tolerance was not a significant predictor of problems.
The results suggested that, controlling for weekly drinking, a low early subjective response protected against acute negative consequences within a sample of heavy drinkers who had acquired significant tolerance to alcohol effects. It is possible that this protective effect may eventually shift to a risk factor by allowing individuals with a low subjective response to persist in a pattern of hazardous drinking.
PMCID: PMC3586307  PMID: 23347236
5.  Predictors of Interest in an Alcohol Reduction Clinical Trial of Naltrexone among Undergraduates 
We tested predictors of interest in a clinical trial of naltrexone plus counseling for heavy drinking reduction in young adults using a web survey. Respondents could indicate interest in the clinical trial at the conclusion of the survey.
A random sample of university students completed the survey (N = 584, 60% female). Data were collected in October-November 2010.
Among past-year drinkers (n = 411), 22.6% (n =93) indicated interest. Equivalent levels of interest were found among past-year heavy drinkers. Non-white race and current cigarette smoking predicted interest. Alcohol-related negative consequences score was a trend-level predictor in the full regression model, but a significant predictor in a reduced model.
Non-white students, smokers and those with a high number of negative consequences may be more amenable to drinking reduction via medication and counseling. These findings could facilitate efforts of researchers, administrators, counselors and other professionals to tailor drinking reduction messages and facilitate treatment engagement by undergraduates.
PMCID: PMC3917969  PMID: 24511431
Alcohol-related consequences; College drinking; Heavy drinking; Impaired control over alcohol use; Pharmacotherapy; Smoking; Web survey
6.  Similarities and Differences between Pathological Gambling and Substance Use Disorders: A Focus on Impulsivity and Compulsivity 
Psychopharmacology  2011;219(2):469-490.
Pathological gambling (PG) has recently been considered as a “behavioral” or non-substance addiction. A comparison of characteristics of PG and substance use disorders (SUDs) has clinical ramifications and could help advance future research on these conditions. Specific relationships with impulsivity and compulsivity may be central to understanding PG and SUDs.
To compare and contrast research findings in PG and SUDs pertaining to neurocogntive tasks, brain function and neurochemistry, with a focus on impulsivity and compulsivity.
Multiple similarities were found between PG and SUDs, including poor performance on neurocognitive tasks, specifically with respect to impulsive choice and response tendencies and compulsive features (e.g., response perseveration and action with diminished relationship to goals or reward). Findings suggest dysfunction involving similar brain regions, including the ventromedial prefrontal cortex (PFC) and striatum and similar neurotransmitter systems, including dopaminergic and serotonergic. Unique features exist which may in part reflect influences of acute or chronic exposures to specific substances.
Both similarities and differences exist between PG and SUDs. Understanding these similarities more precisely may facilitate treatment development across addictions, whereas understanding differences may provide insight into treatment development for specific disorders. Individual differences in features of impulsivity and compulsivity may represent important endophenotypic targets for prevention and treatment strategies.
PMCID: PMC3249521  PMID: 22057662
Iowa Gambling Task; delay discounting; neuroimaging; alcohol; cocaine; dopamine; serotonin; glutamate; frontal cortex; striatum
7.  Drinking Less and Drinking Smarter: Direct and Indirect Protective Strategies in Young Adults 
Efforts to increase the use of protective behavioral strategies are a common component in interventions for young adult drinking. Some strategies, including those utilized while drinking, are directly correlated with lower drinking levels (Cf. Martens et al., 2005). Other strategies, however, may be indirectly related to drinking and instead be more closely associated with alcohol-related consequences. Two studies assessed the Protective Strategies Questionnaire (PSQ; Palmer, 2004), which may be well-suited to the assessment of direct and indirect strategies. In Study 1, data from a sample of undergraduate drinkers (N = 370) was used to examine the structure of the PSQ with principle components analysis (PCA) and confirmatory factor analysis (CFA). In Study 2, data from a clinical sample of young adult drinkers (N = 168) was used to replicate the CFA model. In both studies, relationships among the factors, alcohol use and consequences were examined. PCA and CFA in split halves of the undergraduate sample and CFA in the clinical sample confirmed two factors: a Direct Strategies (e.g. “space drinks out over time”) factor and an Indirect Strategies (e.g. “have a designated driver”) factor. Direct Strategies were associated with lower alcohol consumption. Indirect Strategies were less strongly associated with drinking but were associated with fewer alcohol-related consequences. Interventions for young adult drinking may be tailored to patient goals to decrease consumption and/or consequences.
PMCID: PMC3869566  PMID: 23088406
protective behavioral strategies; young adult drinking; alcohol-related consequences
8.  Nicotine and Food Deprivation Decrease the Ability to Resist Smoking 
Psychopharmacology  2010;212(1):25-32.
Attempts to simultaneously control food intake and smoking may lead to smoking cessation failure. We sought to model this relationship using a human laboratory paradigm of smoking lapse behavior.
We examined the combined effect of food and nicotine deprivation, compared to nicotine deprivation alone, on the ability to resist smoking and on subsequent ad libitum smoking.
In a between-subjects design, daily smokers (N = 30) were all deprived of nicotine for 18 hours and were either food deprived (12 hrs) or not during a laboratory session. Following exposure to individualized food cues, participants had the option of initiating tobacco self-administration or delaying up to 50 minutes in exchange for monetary reinforcement. Subsequently, the tobacco self-administration period consisted of one-hour in which participants could choose to smoke or receive monetary reinforcement for cigarettes not smoked.
Smokers who had been deprived of food and nicotine smoked their first cigarette sooner and were more likely to smoke at some point during the laboratory session, compared to those who were only nicotine deprived. Those who were food and nicotine deprived smoked slightly more cigarettes than those who were nicotine deprived only, although this difference was not statistically significant. There were no sex differences in outcomes. Hunger and food craving ratings while trying to resist smoking were greater in the food + nicotine deprived group. Tobacco craving was predictive of outcome in both conditions.
These findings support the hypothesis that food deprivation can undermine a smoker’s ability to resist smoking.
PMCID: PMC3111597  PMID: 20585761
Tobacco; nicotine; smoking; lapse behavior; human laboratory; food; deprivation; cigarette; cue; craving
9.  Nicotine dependence severity as a cross-sectional predictor of alcohol-related problems in a sample of adolescent smokers 
Nicotine & Tobacco Research  2010;12(5):521-524.
Given the prevalence of alcohol use among adolescents and its negative consequences, it is important to learn more about correlates of alcohol-related problems in this population. Cigarette smoking appears to be associated with alcohol-related problems in adolescents. The purpose of this study was to assess cigarettes smoked per day and nicotine dependence (ND) severity as predictors of alcohol-related problems in cross-sectional models, using data from a smoking cessation clinical trial for adolescents.
Data obtained at intake were used to assess smoking-related variables as cross-sectional predictors of alcohol-related problems in models along with drinks per week and key demographics, using hierarchical multiple regression.
ND severity, as measured using the modified Fagerström Tolerance Questionnaire, significantly predicted alcohol-related problems, both when this score included and did not include an item concerning cigarettes smoked per day. A separate continuous item capturing cigarettes per day did not predict alcohol-related problems.
ND severity predicted alcohol-related problems in cross-sectional regression models, holding constant alcohol consumption and key demographics. This suggests that ND severity may be a clinical indicator of alcohol-related problems among adolescent smokers. To our knowledge, this is the first analysis of associations between smoking and alcohol involvement in a sample of adolescent smokers participating in a clinical trial.
PMCID: PMC2861884  PMID: 20231243
10.  Alcohol-Induced Disinhibition Expectancies and Impaired Control as Prospective Predictors of Problem Drinking in Undergraduates 
Trait disinhibition is associated with problem drinking and alcohol drinking itself can bring about a state of disinhibition. It is unclear however, if expectancies of alcohol-induced disinhibition are unique predictors of problem drinking. Impaired control (i.e., difficulty in limiting alcohol consumption) may be related to disinhibition expectancies in that both involve issues of control related to alcohol use. Data from a prospective survey of undergraduates assessed during freshman (N = 337) and senior year (N = 201) were analyzed to determine whether subscales of the Drinking-Induced Disinhibition Scale and the Impaired Control Scale predicted unique variance in heavy episodic drinking and alcohol-related problems. In Time 1 cross-sectional models, dysphoric disinhibition expectancies predicted alcohol-related problems and impaired control predicted both alcohol-related problems and heavy episodic drinking. In prospective models, Time 1 impaired control predicted Time 2 alcohol-related problems and Time 1 euphoric/social disinhibition expectancies predicted Time 2 heavy episodic drinking. These findings suggest that expectancies of alcohol-induced disinhibition and impaired control predict unique variance in problem drinking cross-sectionally and prospectively and that these phenomena should be targeted in early intervention efforts.
PMCID: PMC2805107  PMID: 20025361
alcohol; college drinking; disinhibition; impaired control; prospective models
11.  Craving Predicts Within Session Drinking Behavior Following Placebo 
Tiffany’s (1990) cognitive processing model postulates that craving will only occur when access to alcohol is blocked. To test a hypothesis based on this model, we analyzed data from a naturalistic laboratory alcohol challenge study involving moderate-to-heavy drinking young adults (N = 174) with a focus on the placebo beverage condition of this study. Our hypothesis was that self-reports of “wanting more alcohol” (i.e., craving) in the lab, following placebo, would predict subsequent ad libitum consumption because placebo administration would constitute partial blocking of access to alcohol. We also tested the possibility that craving might mediate associations between personality traits and ad libitum consumption. Both trait disinhibition and reports of craving following the placebo beverage significantly predicted ad libitum consumption. Further, craving partially mediated the association between trait disinhibition and ad libitum consumption. Potential implications of these findings are discussed.
PMCID: PMC2699682  PMID: 20161258
Alcohol; alcohol challenge; craving; disinhibition; harm avoidance; impulsivity; inhibition; placebo
12.  A Pilot Study of Naltrexone and BASICS for Heavy Drinking Young Adults 
Addictive behaviors  2008;33(8):1048-1054.
Heavy drinking young adults often have limited motivation to change their drinking behavior. Adding pharmacotherapy to brief counseling is a novel approach to treating this population. A small open-label pilot study was conducted to assess the feasibility of offering eight weeks of daily and targeted (i.e., taken as needed in anticipation of drinking) naltrexone with BASICS (brief motivational) counseling to heavy drinking young adults; to assess the tolerability of the medication in this population and to obtain preliminary efficacy data. The sample (N = 14) showed strong adherence to study appointments and medication taking, supporting the feasibility of this approach. Overall, the medication was well-tolerated. Significant reductions from baseline were observed in drinks per drinking day and in percent heavy drinking days and these gains were maintained one month after treatment ended. A significant decrease in alcohol-related consequences was also observed. Findings from this small pilot study suggest that naltrexone in combination with BASICS represents a promising strategy to reduce heavy drinking among young adults.
PMCID: PMC2568078  PMID: 18502591
Naltrexone; young adult drinking; undergraduate drinking; heavy drinking; alcohol-related consequences; BASICS
13.  Impaired Control and Undergraduate Problem Drinking 
Impaired control, one of the hallmarks of addiction, is also one of the earliest dependence symptoms to develop. Thus impaired control is particularly relevant to undergraduates and other young adults with relatively brief drinking histories. The main goal of this study was to determine whether impaired control predicted heavy episodic drinking and alcohol-related problems cross-sectionally in an undergraduate sample after controlling for gender, family history of alcohol and drug problems and several other established predictor variables from the undergraduate alcohol literature.
A sample of first-year undergraduates (N = 312) completed Part 2 of the Impaired Control Scale (ICS; Heather et al., 1993) and other measures related to alcohol use as part of a larger study on problem drinking in undergraduates.
Scores on Part 2 of the ICS predicted heavy episodic drinking and alcohol-related problems cross-sectionally even after controlling for all other predictor variables. Notably, impaired control was a stronger predictor of alcohol-related problems than overall weekly alcohol consumption. Part 2 of the ICS was found to be a reliable and valid measure for use with undergraduates.
These findings support the notion that impaired control is one of the earliest dependence symptoms to develop. The ICS is an effective tool for identifying young adults at risk for problem drinking.
PMCID: PMC2430104  PMID: 17142826
Impaired control; undergraduate drinking; alcohol-related problems; heavy episodic drinking
14.  The Drinking-Induced Disinhibition Scale (DIDS): A Measure of Three Types of Disinhibiting Effects 
Addictive behaviors  2006;32(6):1200-1219.
Links between trait disinhibition and high-risk drinking are well established. It is also known that alcohol has disinhibiting effects. Nonetheless, there is no measure in the literature devoted exclusively to assessing disinhibiting effects of alcohol. The multidimensional Drinking-Induced Disinhibition Scale (DIDS) was developed as part of Study I, a prospective survey conducted with undergraduates (N = 337). Study II, a cross-sectional survey (N = 260), allowed for a confirmatory factor analysis and further validation of the measure through comparisons with an expectancies scale. The nine-item DIDS is comprised of three subscales assessing euphoric/social, dysphoric and sexual disinhibition. All three subscales had good internal consistency and adequate test-retest reliability. Convergent and discriminant validity were established in both studies. The subscales had different associations with high-risk drinking: sexual disinhibition predicted heavy episodic drinking; dysphoric disinhibition predicted alcohol-related problems and euphoric/social had associations with both. A cluster analysis revealed four distinct disinhibition profiles (i.e., low effect drinker; high euphoric/social only; high euphoric social and dysphoric; high euphoric/social and sexual), which predicted likelihood of high-risk drinking.
PMCID: PMC1910701  PMID: 16989958
disinhibition; undergraduate drinking; psychometrics; alcohol-related problems; heavy episodic drinking
15.  Exercise as an adjunct to nicotine gum in treating tobacco dependence among women 
This was the first randomized, controlled smoking cessation trial assessing the efficacy of an exercise intervention as an adjunct to nicotine gum therapy in comparison to both equal contact control and standard care control conditions. Sedentary female smokers aged 18-55 were provided with nicotine gum treatment along with brief behavioral counseling and were randomized into one of these three behavioral adjunct conditions. In the “intent-to-treat” sample (N=182), at end of treatment and at one-year follow up, there were clear, but non-significant, trends in univariate analyses in which the exercise and equal contact control conditions both had higher rates of abstinence than the standard care control. However, when adjusting for other predictors of relapse in a multiple logistic regression, both exercise and equal contact control showed an advantage over standard care control in avoiding early relapse (i.e., after 1 week). In a multivariate survival model adjusting for other predictors, the equal contact condition had a significantly lower likelihood of relapse compared to the standard care condition and there was a near significant trend in which exercise offered an advantage over standard care as well. While these findings suggest a slightly improved likelihood of abstinence with exercise compared with standard care, exercise did not differ from equal contact control in its efficacy. Potential explanations for these equivalent levels of efficacy and implications for the findings are discussed.
PMCID: PMC3695732  PMID: 18418791
16.  Impulse control disorders in Parkinson's disease: background and update on prevention and management 
Given that impulse control disorders (ICDs) have been identified among a considerable minority of Parkinson's disease (PD) patients, these conditions have gained increased clinical and research attention in the past decade. Dopamine-replacement therapies, taken to ameliorate PD symptoms, have been associated with ICDs in PD. Unfortunately, there are relatively sparse empirical data regarding how best to address ICDs in PD patients. Conversely, progress has been made in understanding the clinical, neurobiological and cognitive correlates of ICDs in PD. Some of these findings may inform possible courses of action for care providers working with PD patients with ICDs. The literature on ICDs in non-PD populations may also be informative in this regard. The goals of the present article are to outline important clinical characteristics of ICDs in PD, briefly review relevant neurocognitive and neurobiological studies and discuss possible ways to prevent and manage ICDs in PD.
PMCID: PMC3627213  PMID: 23606908
17.  Co-Occurring Marijuana Use is Associated with Medication Nonadherence and Nonplanning Impulsivity in Young Adult Heavy Drinkers 
Addictive Behaviors  2011;37(4):420-426.
Few studies have examined the co-occurrence of alcohol and marijuana use in clinical samples of young adults. The present study investigated whether co-occurring marijuana use is associated with characteristics indicative of a high level of risk in young adult heavy drinkers. Individuals between the ages of 18 and 25 years (N = 122) participated in an ongoing 8-week randomized clinical trial that tested the efficacy of placebo-controlled naltrexone plus brief individual counseling to reduce heavy drinking. At intake participants completed self-report assessments on alcohol consumption, alcohol-related negative consequences, motivation to reduce drinking, trait impulsivity, expectancies for alcohol-induced disinhibition, use of cigarettes, and history of medication nonadherence. In univariate tests heavy drinkers with and without co-occurring marijuana use did not differ on alcohol consumption, most alcohol-related negative consequences, and motivation to reduce drinking. In multivariate tests controlling for demographic characteristics, co-occurring heavy alcohol and marijuana use was significantly associated with nonplanning impulsivity (β = 2.95) and a history of both unintentional (adjusted odds ratio [aOR] = 3.30) and purposeful (aOR = 3.98) nonadherence to medication. Findings suggest that young adult heavy drinkers with co-occurring marijuana use exhibit a high-risk clinical profile and may benefit from interventions that increase adherence to medications.
PMCID: PMC3288288  PMID: 22189052
alcohol; marijuana; co-occurring; impulsivity; college drinking; medication adherence
18.  Impaired Control over Alcohol Use: An Under-Addressed Risk Factor for Problem Drinking in Young Adults? 
Impaired control over alcohol use may be defined as “a breakdown of an intention to limit consumption in a particular situation” (Heather, Tebbutt, Mattick, & Zamir, 1993, p. 701) and has long been considered an important feature of alcohol dependence. Evidence suggests impaired control is highly relevant to young adult problem drinking. In the natural history of problem drinking, impaired control tends to develop early and may predict alcohol-related problems prospectively in undergraduates. Impaired control over alcohol use may be a facet of generalized behavioral under-control specifically related to drinking. In particular, impaired control is theoretically and empirically related to impulsivity. The question of whether impaired control represents a facet of impulsivity or a related but separate construct requires further study. However, theoretical arguments and empirical evidence suggest that there are unique qualities to the constructs. Specifically, existing data suggest that self-report measures of impaired control and impulsivity over alcohol use relate distinctly to problem drinking indices in young adults. Several lines of future research concerning impaired control are suggested, using the impulsivity literature as a guide. We conclude that impaired control is a valuable construct to the study of young adult problem drinking and that measures of impaired control should be included in more young adult alcohol studies. The extent to which impaired control over the use of other substances and impaired control over engagement in other addictive behaviors are clinically relevant constructs requires additional study.
PMCID: PMC3613490  PMID: 22182417
alcohol; alcohol-related problems; college drinking; dopamine; impulsivity
19.  A Latent Class Analysis of DSM-IV Alcohol Use Disorder Criteria and Binge Drinking in Undergraduates 
Adolescent and adult samples have shown that DSM-IV abuse and dependence criteria lie on a continuum of alcohol problem severity, but information on criteria functioning in college students is lacking. Prior factor analyses in a college sample (Beseler et al., 2010) indicated that a two-factor solution fit the data better than a single-factor solution after a binge drinking criterion was included. The second dimension may indicate a clustering of criteria related to excessive alcohol use in this college sample.
The present study was an analysis of data from an anonymous, online survey of undergraduates (N = 361) that included items pertaining to the DSM-IV alcohol use disorder (AUD) diagnostic criteria and binge drinking. Latent class analysis (LCA) was used to determine whether the criteria best fit a categorical model, with and without a binge drinking criterion.
In a LCA including the AUD criteria only, a 3-class solution was the best fit. Binge drinking worsened the fit of the models. The largest class (class 1, n = 217) primarily endorsed tolerance (18.4%); none were alcohol dependent. The middle class (class 2, n = 114) endorsed primarily tolerance (81.6%) and drinking more than intended (74.6%); 34.2% met criteria for dependence. The smallest class (class 3, n = 30) endorsed all criteria with high probabilities (30% to 100%); all met criteria for dependence. Alcohol consumption patterns did not differ significantly between classes 2 and 3. Class 3 was characterized by higher levels on several variables thought to predict risk of alcohol-related problems (e.g., enhancement motives for drinking, impulsivity and aggression).
Two classes of heavy drinking college students were identified, one of which appeared to be at higher risk than the other. The highest risk group may be less likely to “mature out” of high-risk drinking after college.
PMCID: PMC3253200  PMID: 22004067
alcohol use disorders; latent class analysis; college students; impulsivity; alcohol typology
20.  Impulse control disorders in Parkinson's disease: clinical characteristics and implications 
Neuropsychiatry  2011;1(2):133-147.
Impulse control disorders (ICDs), specifically those related to excessive gambling, eating, sex and shopping, have been observed in a subset of people with Parkinson's disease (PD). Although some initial case reports claimed that dopamine replacement therapies, particularly dopamine agonists, cause ICDs, more recent, larger and better controlled studies indicate a more complicated picture. While dopamine replacement therapy use is related to ICDs, other vulnerabilities, some related to PD and/or its treatment directly and others seemingly unrelated to PD, have also been associated with ICDs in PD. This suggests a complex etiology with multiple contributing factors. As ICDs occur in a sizable minority of PD patients and can be associated with significant distress and impairment, further investigation is needed to identify factors that can predict who may be more likely to develop ICDs. Clinical implications are discussed and topics for future research are offered.
PMCID: PMC3120055  PMID: 21709778
21.  Dose Dependent Reduction of Hazardous Alcohol Use in a Placebo-Controlled Trial of Naltrexone for Smoking Cessation 
The opiate antagonist naltrexone has demonstrated efficacy in the treatment of alcohol dependence and as a component of treatment to reduce heavy drinking. At present, there are no published dose-ranging clinical trials of the oral preparation for treatment of problem drinking. The present study evaluated the effects of naltrexone on alcohol use among the subset of hazardous drinkers (N = 102) who participated in a placebo-controlled, dose-ranging trial of oral naltrexone (25 mg, 50 mg and 100 mg doses) combined with open-label transdermal nicotine patch for enhancing smoking cessation. On the primary outcome—no hazardous drinking (drinking that exceeded weekly or daily limits) during treatment—25 mg and 50 mg naltrexone were superior to placebo (each p < 0.05). These findings remained after controlling for baseline predictors or smoking abstinence during treatment. Time to remission of hazardous drinking was examined as a secondary outcome with definitions of hazardous drinking based on weekly limits, daily limits and the combination of weekly and daily limits and the results were consistent with the primary findings. In conclusion, the findings suggest that naltrexone can reduce the risk of hazardous drinking in smokers who are not seeking or receiving alcohol treatment, providing strong evidence for the pharmacological effects of naltrexone on drinking. This effect appears to favor lower doses that may be better tolerated and less expensive than the higher 100 mg dose. Given its efficacy and favorable side effect profile, the 25 mg dose should be considered for future studies of combination therapy.
PMCID: PMC3094855  PMID: 18796184
smoking cessation; heavy drinking; drinking reduction; naltrexone; measurement sensitivity
22.  Ethanol Consumption: How Should We Measure It? Achieving Consilience between Human and Animal Phenotypes 
Addiction biology  2010;15(2):109-124.
There is only modest overlap in the most common alcohol consumption phenotypes measured in animal studies and those typically studied in humans. To address this issue, we identified a number of alcohol consumption phenotypes of importance to the field that have potential for consilience between human and animal models. These phenotypes can be broken down into three categories: 1) abstinence/the decision to drink or abstain; 2) the actual amount of alcohol consumed and 3) heavy drinking. A number of suggestions for human and animal researchers are made in order to address these phenotypes and enhance consilience. Laboratory studies of the decision to drink or abstain are needed in both human and animal research. In human laboratory studies, heavy or binge drinking that meets cut-offs used in epidemiological and clinical trials should be reported. Greater attention to patterns of drinking over time is needed in both animal and human studies. Individual differences pertaining to all consumption phenotypes should be addressed in animal research. Lastly, improved biomarkers need to be developed in future research for use with both humans and animals. Greater precision in estimating blood alcohol levels in the field together with consistent measurement of breath/blood alcohol levels in human laboratory and animal studies provides one means of achieving greater consilience of alcohol consumption phenotypes.
PMCID: PMC2861719  PMID: 20148775
alcohol; animal models; biomarkers; genetics; heavy drinking; human laboratory models
23.  Understanding the construct of impulsivity and its relationship to alcohol use disorders 
Addiction biology  2010;15(2):217-226.
There are well-established links between impulsivity and alcohol use in humans and other model organisms; however, the etiological nature of these associations remains unclear. This is likely due, in part, to the heterogeneous nature of the construct of impulsivity. Many different measures of impulsivity have been employed in human studies, using both questionnaire and laboratory-based tasks. Animal studies also use multiple tasks to assess the construct of impulsivity. In both human and animal studies, different measures of impulsivity often show little correlation and are differentially related to outcome, suggesting that the impulsivity construct may actually consist of a number of more homogeneous (and potentially more meaningful) subfacets. Here, we provide an overview of the different measures of impulsivity used across human and animal studies, evidence that the construct of impulsivity may be better studied in the context of more meaningful subfacets, and recommendations for how research in this direction may provide for better consilience between human and animal studies of the connection between impulsivity and alcohol use.
PMCID: PMC2895996  PMID: 20148781
Behavioral disinhibition; behavioral undercontrol; delay aversion; impulsivity; response inhibition; sensation-seeking
24.  The Inclusion of Women and Minorities in Smoking Cessation Clinical Trials: A Systematic Review 
This study assesses the impact of the 1993 NIH Revitalization Act on the inclusion and subgroup analysis of women and minorities in trials of FDA-approved smoking cessation pharmacotherapy. Female representation, while commensurate with population levels, declined significantly for trials that began recruitment after 1993 (M = 47.2% vs. M=53.9%) and fewer than half reported analyses by gender. Minorities continued to be under-represented in later trials, however, significant improvement in representation (M=16.1% vs. M=10%) and analysis by race occurred. Industry sponsored studies had lower minority representation than NIH funded studies. Recommendations are offered to improve subgroup analyses and minority inclusion.
PMCID: PMC2764011  PMID: 19219662
females; minorities; smoking cessation; research methods
25.  Behavioral and Neurological Foundations for the Moral and Legal Implications of Intoxication, Addictive Behaviors and Disinhibition 
Behavioral sciences & the law  2009;27(2):237-259.
Disinhibition and addictive behaviors are related and carry moral implications. Both typically involve diminished consideration of negative consequences, which may result in harm to oneself or others. Disinhibition may occur on state and trait levels, and addictive substances may elicit disinhibitory states, particularly when intoxication is reached. Data suggest that trait disinhibition and addictions may be conceptualized as involving misdirected motivation with underlying biological bases including genetic factors, alterations in neurotransmitter systems and differences in regional brain function. The influences of intoxication on the brain share similarities with cognitive impairments in individuals with chronic substance abuse and those with trait disinhibition related to frontal lobe injuries. These findings raise questions about volitional impairment and morality. Although impaired volition related to disinhibition and addictive behaviors has been studied from multiple perspectives, additional research is needed to further characterize mechanisms of impairment. Such findings may have important implications in multiple legal and psychiatric domains.
PMCID: PMC2748412  PMID: 19241397
addiction; alcohol; disinhibition; impulsivity; intoxication; morality

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