Findings

Under the Influence

Kevin Lewis

January 24, 2010

Cognitive control of drug craving inhibits brain reward regions in cocaine abusers

Nora Volkow, Joanna Fowler, Gene-Jack Wang, Frank Telang, Jean Logan, Millard Jayne, Yeming Ma, Kith Pradhan, Christopher Wong & James Swanson
NeuroImage, 1 February 2010, Pages 2536-2543

Abstract:
Loss of control over drug taking is considered a hallmark of addiction and is critical in relapse. Dysfunction of frontal brain regions involved with inhibitory control may underlie this behavior. We evaluated whether addicted subjects when instructed to purposefully control their craving responses to drug-conditioned stimuli can inhibit limbic brain regions implicated in drug craving. We used PET and 2-deoxy-2[18F]fluoro-d-glucose to measure brain glucose metabolism (marker of brain function) in 24 cocaine abusers who watched a cocaine-cue video and compared brain activation with and without instructions to cognitively inhibit craving. A third scan was obtained at baseline (without video). Statistical parametric mapping was used for analysis and corroborated with regions of interest. The cocaine-cue video increased craving during the no-inhibition condition (pre 3 ± 3, post 6 ± 3; p < 0.001) but not when subjects were instructed to inhibit craving (pre 3 ± 2, post 3 ± 3). Comparisons with baseline showed visual activation for both cocaine-cue conditions and limbic inhibition (accumbens, orbitofrontal, insula, cingulate) when subjects purposefully inhibited craving (p < 0.001). Comparison between cocaine-cue conditions showed lower metabolism with cognitive inhibition in right orbitofrontal cortex and right accumbens (p < 0.005), which was associated with right inferior frontal activation (r = - 0.62, p < 0.005). Decreases in metabolism in brain regions that process the predictive (nucleus accumbens) and motivational value (orbitofrontal cortex) of drug-conditioned stimuli were elicited by instruction to inhibit cue-induced craving. This suggests that cocaine abusers may retain some ability to inhibit craving and that strengthening fronto-accumbal regulation may be therapeutically beneficial in addiction.

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Reducing the desire for cocaine with subthalamic nucleus deep brain stimulation

Tiphaine Rouaud, Sylvie Lardeux, Nicolas Panayotis, Dany Paleressompoulle, Martine Cador & Christelle Baunez
Proceedings of the National Academy of Sciences, forthcoming

Abstract:
Deep brain stimulation (DBS) is a reversible technique that is currently used for the treatment of Parkinson disease and may be suitable for the treatment of psychiatric disorders. Whether DBS inactivates the target structure is still a matter of debate. Here, from findings obtained in rats, we propose DBS of the subthalamic nucleus (STN) as a possible treatment for cocaine addiction to be further tested in human studies. We show that STN DBS reversibly reduces the motivation to work for an i.v. injection of cocaine, and it increases motivation to work for sucrose pellets. These opposite effects may result from STN DBS effect on the positive affective properties of these rewards. Indeed, we further show that STN DBS reduces the preference for a place previously associated with the rewarding properties of cocaine, and it increases the preference for a place associated with food. Because these findings are consistent with those observed after STN lesions [Baunez C, Dias C, Cador M, Amalric M (2005) Nat Neurosci 8:484-489], they suggest that STN DBS mimics an inactivation of the STN on motivational processes. Furthermore, given that one of the major challenges for cocaine addiction is to find a treatment that reduces the craving for the drug without diminishing the motivation for naturally rewarding activities, our findings validate STN as a good target and DBS as the appropriate technique for a promising therapeutic strategy in the treatment of cocaine addiction.

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A Night to Remember: A Harm-Reduction Birthday Card Intervention Reduces High-Risk Drinking During 21st Birthday Celebrations

Joseph LaBrie, Savannah Migliuri & Jessica Cail
Journal of American College Health, May-June 2009, Pages 659-663

Objective: In collaboration with Residence Life, the Heads UP research team developed a 21st birthday card program to help reduce the risky drinking often associated with these celebrations.

Participants: 81 students (28 males, 53 females) completed a post-21st birthday survey. Of these, 74 reported drinking during their 21st birthday and were included in the analyses.

Methods: During the 2005-2006 school year, the authors assigned students celebrating 21st birthdays to either receive an alcohol risk-reduction birthday card or to a no-card condition. The students completed a survey after their birthday.

Results: Students who received the card consumed fewer drinks and reached lower blood alcohol content (BAC) levels on their birthday than did students who did not receive it. Female students who received the card consumed 40% fewer drinks and reached nearly 50% lower BAC levels than women who did not receive it.

Conclusion: This program is easily replicated, inexpensive, and may be used by universities to reduce risk related to celebratory alcohol consumption.

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Sexual orientation and drug use in a longitudinal cohort study of U.S. adolescents

Heather Corliss, Margaret Rosario, David Wypij, Sarah Wylie, Lindsay Frazier & Bryn Austin
Addictive Behaviors, forthcoming

Abstract:
Adolescents with a minority sexual orientation (e.g., lesbian, gay, bisexual) are more likely to use substances than their heterosexual peers. This study aimed to increase understanding of the development of drug use in this vulnerable population by: 1) comparing longitudinal patterns of past-year illicit drug use (e.g., marijuana, cocaine, ecstasy) and misuse of prescription drugs among minority sexual orientation youth relative to heterosexual youth and, 2) examining how sexual orientation subgroup, gender, and age relate to variation in risk of drug use. Data come from the Growing Up Today Study, a community-based cohort of adolescents who were assessed three times between 1999-2005 with self-administered questionnaires when they ranged in age from 12 to 23 years (N = 12,644; 74.9% of the original cohort). Multivariable repeated measures generalized estimating equations using modified Poisson regression was used to estimate relative risks. Participants indicating their sexual orientation was mostly heterosexual, bisexual, or lesbian/gay were more likely than completely heterosexual youth to report past-year illicit drug use and misuse of prescription drugs. Gender was an important modifier; bisexual females were most likely to report drug use. Age was also an important modifier of risk; differences in drug use between minority sexual orientation and heterosexual youth were larger during adolescence (12-17 years) than during emerging adulthood (18-23 years). Research must focus on identifying reasons why minority sexual orientation youth are at disproportionate risk for drug use. Such information is essential for developing interventions that are critically needed to reduce drug use in this population. Efforts need to begin early because large sexual orientation disparities in drug use are evident by adolescence.

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Selection and the effect of prenatal smoking

Angela Fertig
Health Economics, February 2010, Pages 209-226

Abstract:
There is a debate about the extent to which the effect of prenatal smoking on infant health outcomes is causal. Poor outcomes could be attributable to mother characteristics, which are correlated with smoking. I examine the importance of selection on the effect of prenatal smoking by using three British cohorts where the mothers' knowledge about the harms of prenatal smoking varied substantially. I find that the effect of smoking on the probability of a low birth weight birth conditional on gestation is slightly more than twice as large in 2000 compared with 1958, implying that selection could explain as much as 50% of the current association between smoking and birth outcomes.

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Event-level analyses of energy drink consumption and alcohol intoxication in bar patrons

Dennis Thombs, Ryan O′Mara, Miranda Tsukamoto, Matthew Rossheim, Robert Weiler, Michele Merves & Bruce Goldberger
Addictive Behaviors, forthcoming

Aim: To assess event-level associations between energy drink consumption, alcohol intoxication, and intention to drive a motor vehicle in patrons exiting bars at night.

Method: Alcohol field study. Data collected in a U.S. college bar district from 802 randomly selected and self-selected patrons. Anonymous interview and survey data were obtained as well as breath alcohol concentration (BrAC) readings.

Results: Results from logistic regression models revealed that patrons who had consumed alcohol mixed with energy drinks were at a 3-fold increased risk of leaving a bar highly intoxicated (BrAC ≥ 0.08 g/210 L), as well as a 4-fold increased risk of intending to drive upon leaving the bar district, compared to other drinking patrons who did not consume alcoholic beverages mixed with energy drinks.

Discussion: These event-level associations provide additional evidence that energy drink consumption by young adults at bars is a marker for elevated involvement in nighttime risk-taking behavior. Further field research is needed to develop sound regulatory policy on alcohol/energy drink sales practices of on-premise establishments.

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Binge drinking and labor market success: A longitudinal study on young people

Shao-Hsun Keng & Wallace Huffman
Journal of Population Economics, January 2010, Pages 303-322

Abstract:
This paper presents a two-equation model of joint outcomes on an individual's decision to binge drink and on his/her annual labor market earnings. The primary data source is the 1979 cohort of the National Longitudinal Survey of Youth (NLSY79), 1979-1994. We show that binge drinking behavior is quite alcohol-price responsive and is a rational addiction. A new result is that an individual's decision to binge drink has a statistically significant negative effect on his/her earnings. Furthermore, we conducted simulations of the short-run and long-run impacts of increasing the alcohol price. They showed that the tendency for an individual to binge drink heavily is reduced significantly, and the reduction is greater in the long-run than short-run simulation. Also, an individual's annual earnings were increased. However, in the structural model, an individual's earnings have no significant effect on his/her tendency to engage in binge drinking. Our results contradict earlier findings from cross-section evidence that showed increased alcohol consumption raised an individual's earnings or wages.

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Cracking down on youth tobacco may influence drug use

Leonard Jason, Steven Pokorny, Monica Adams, Annie Nihls, Hyo Yeon Kim & Yvonne Hunt
Journal of Community Psychology, January 2010, Pages 1-15

Abstract:
This study evaluated the influence of tobacco possession-use-purchase (PUP) law enforcement and illicit drug use and offers. Twenty-four towns were randomly assigned into two conditions. Both conditions focused on reducing minors' access to commercial sources of tobacco. The communities assigned to the experimental condition also increased their PUP law enforcement, whereas among communities in the control condition, PUP law enforcement remained at low levels. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The likelihood of a child currently using drugs, ever having used drugs, or illicit drug offers was lower in the experimental versus control conditions. These outcomes suggest that police efforts to reduce specific substance use behaviors (i.e., underage tobacco use) may have a positive spillover effect and help reduce teen drug use and illicit drug offers.

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Event-Specific Analyses of Poly-Drug Abuse and Concomitant Risk Behavior in a College Bar District in Florida

Dennis Thombs, Ryan O'Mara, Virginia Dodd, Michele Merves, Robert Weiler, Bruce Goldberger, Steven Pokorny, Christine Moore, Jennifer Reingle & Sara Gullet
Journal of American College Health, May-June 2009, Pages 575-586

Objective: The authors describe the epidemiology of risk behavior associated with poly-drug use in a college bar district of a large campus community.

Participants: A total of 469 bar patrons participated in the study.

Methods: The authors used self-report data and biological measures collected from patrons outside bars in July and August of 2007.

Results: The mean breath alcohol concentration of the exiting patrons was 0.09. Illicit and prescription drug use on the nights of data collection and in the recent past were significant features of the profile of patron risk behavior. About one-quarter of the patrons using only alcohol reported an intention to drive a vehicle within 60 minutes of leaving an establishment, compared with almost one-half of those using both alcohol and marijuana.

Conclusions: A substantial amount of high-risk behavior was generated from the bar district on 4 typical nights. College bar districts should be a priority focus for prevention efforts.

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Relationship of high school and college sports participation with alcohol, tobacco, and illicit drug use: A review

Nadra Lisha & Steve Sussman
Addictive Behaviors, forthcoming

Abstract:
This study provides an exhaustive review of 34 peer-reviewed quantitative data-based studies completed on high school and college sports involvement and drug use. The studies reviewed suggest that participation in sport is related to higher levels of alcohol consumption, but lower levels of both cigarette smoking and illegal drug use. Additional research is needed in this domain to further elucidate the relationship between these variables.

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Behavioral Impact of Graduated Driver Licensing on Teenage Driving Risk and Exposure

Pinar Karaca-Mandic
Journal of Health Economics, forthcoming

Abstract:
Graduated Driver Licensing (GDL) is a critical policy tool for potentially improving teenage driving while reducing teen accident exposure. While previous studies demonstrated that GDL reduces teenage involvement in fatal crashes, much remains unanswered. We explore the mechanisms through which GDL influences accident rates as well as its long term effectiveness on teen driving. In particular, we investigate; 1) whether GDL policies improve teenage driving behavior, or simply reduce teenage prevalence on the roads; 2) whether GDL exposed teens become better drivers in later years. We employ a unique data source, the State Data System, which contains all police reported accidents (fatal and non-fatal) during 1990-2005 for twelve states. We estimate a structural model that separately identifies GDL's effect on relative teenage prevalence and relative teenage riskiness. Identification of the model is driven by the relative numbers of crashes between two teenagers, two adults, or a teenager and an adult. We find that the GDL policies reduce the number of 15-17 year-old accidents by limiting the amount of teenage driving rather than by improving teenage driving. This prevalence reduction primarily occurs at night and stricter GDL policies, especially those with night-time driving restrictions, are the most effective. Finally, we find that teen driving quality does not improve ex-post GDL exposure.


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