Dose of reality
Shepard Siegel
Current Directions in Psychological Science, December 2016, Pages 375-379
Abstract:
Heroin overdose deaths in the Unites States more than tripled from 2010 to 2014, reaching almost 11,000 per year. Despite the use of the term “overdose,” many of these victims died after self-administering an amount of opiate that would not be expected to be fatal for these drug-experienced, and drug-tolerant, individuals. Various explanations of this overdose mystery have been proposed. I describe an explanation based on Pavlovian conditioning. Organisms associate cues present at the time of drug administration with the systemic effect of the drug. These drug-predictive cues come to elicit responses that attenuate the effect of a drug. Such anticipatory conditional responses mediate chronic tolerance. If the drug is administered in the presence of novel cues, tolerance fails to occur and the victim suffers an overdose. Overdose prevention strategies should incorporate information about the contribution of drug-associated cues to drug tolerance.
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Lora Cope et al.
Alcohol, forthcoming
Abstract:
The serotonin transporter-linked polymorphic region (5-HTTLPR) of the serotonin transporter gene (SLC6A4) has been previously associated with alcohol-related risk. Most findings point to short (S) allele carriers being at increased risk for negative alcohol outcomes relative to long allele homozygotes, although some work indicates a more complex relationship. The current prospective study aimed to clarify how and under what circumstances variations in 5-HTTLPR transmit risk for various alcohol-related outcomes. Participants were 218 adolescents and young adults (29% female) enrolled in the Michigan Longitudinal Study. We tested a moderated mediation model with 5-HTTLPR as the predictor, Self-Rating of the Effects of Alcohol (SRE) score as the mediator, alcohol-related outcomes as the dependent variables, parental monitoring as the moderator of the SRE to alcohol outcomes path, and prior drinks, sex, age, and body mass index as covariates. Four alcohol-related outcomes were tested. The S allele was associated with higher SRE scores (i.e., lower response to alcohol). Parental monitoring was a significant moderator: At low levels of parental monitoring, higher SRE scores predicted more drinks consumed and binge drinking episodes. At high levels of monitoring, higher SRE scores were significantly related to fewer alcohol-related problems. Findings suggest that one mechanism by which 5-HTTLPR variation transmits alcohol-related risk is through level of response to alcohol. Furthermore, the strength and direction of this effect varied by level of parental monitoring, indicating that even in the presence of genetic and physiological vulnerability, parents can influence the likelihood of offspring developing problematic alcohol-related behaviors.
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Michael Pesko & Janet Currie
NBER Working Paper, November 2016
Abstract:
We use United States birth record data to estimate the effect of e-cigarette minimum legal sale age laws on cigarette use and birth outcomes for pregnant teenagers. While these laws may have reduced e-cigarette use, we hypothesize that these laws may have also increased cigarette use during pregnancy by making it more difficult to use e-cigarettes to reduce/quit smoking. We use cross-sectional and panel data models to find that e-cigarette minimum legal sale age laws increase underage pregnant teenagers’ smoking by 2.1 percentage points. The laws may have also modestly improved select birth outcomes, perhaps by reducing overall nicotine exposure from vaping and smoking combined.
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Karma McKelvey & Bonnie Halpern-Felsher
Journal of Adolescent Health, forthcoming
Methods: Data from two California school-based studies (Xage = 14) were compared: one conducted in 2001–2002 (“2001”), N = 395; the second in 2014–2015 (“2015”); N = 282.
Results: In 2015, more participants reported it was very unlikely they would smoke (94% vs. 65%) and that they never smoked (95% vs. 74%); they reported perceiving less likelihood of looking more mature (17% vs. 28%) and greater likelihood of getting into trouble (86% vs. 77%), having a heart attack (76% vs. 69%), and contracting lung cancer (85% vs. 78%) from smoking (p < .001). Perceptions of short-term health problems and addiction were similar in 2001 and 2015.
Conclusions: Findings suggest that adolescents in 2015 perceived greater risks compared to those in 2001 even amidst the rapidly changing tobacco product landscape. In addition to continuing messages of long-term health risks, prevention efforts should include messages about addiction and short-term health and social risks.
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Changing Perceptions of Harm of E-Cigarettes Among U.S. Adults, 2012–2015
Ban Majeed et al.
American Journal of Preventive Medicine, forthcoming
Introduction: Although the impact of long-term use of electronic cigarettes (e-cigarettes) on health is still unknown, current scientific evidence indicates that e-cigarettes are less harmful than combustible cigarettes. The study examined whether perceived relative harm of e-cigarettes and perceived addictiveness have changed during 2012–2015 among U.S. adults.
Methods: Data were from Tobacco Products and Risk Perceptions surveys of probability samples representative of U.S. adults in 2012, 2014, and 2015. Changes over time in perceived harmfulness of e-cigarettes were examined using pairwise comparisons of proportions and multinomial logistic regression analysis. Analyses were conducted in January 2016.
Results: Whereas 11.5% and 1.3% of adults perceived e-cigarettes to have about the same level of harm and to be more harmful than cigarettes, respectively, in 2012, 35.7% and 4.1% did so in 2015. The proportion of adults who thought e-cigarettes were addictive more than doubled during 2012–2015 (32.0% in 2012 vs 67.6% in 2015). Compared with 2012, the odds of perceiving e-cigarettes to be equally or more harmful (than to be less harmful) doubled (95% CI=1.64, 2.41) in 2014, and tripled (95% CI=2.60, 3.81) in 2015.
Conclusions: There is an increase in the proportion of U.S. adults who misperceive the harm of e-cigarettes and consider them to be as harmful as combustible cigarettes. The study highlights the need to design public health messages that accurately interpret the scientific data on the potential harm of e-cigarettes and clearly differentiate the absolute from the relative harm of e-cigarettes.
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Julie Johnson, Dominic Hodgkin & Sion Kim Harris
Drug and Alcohol Dependence, January 2017, Pages 1–8
Objectives: To assess the association between U.S. state medical marijuana laws (MML), the most liberal category of marijuana policies before legalization, their specific provisions, and adolescent past-30-day use and heavy marijuana use.
Methods: This quasi-experimental study used state Youth Risk Behavior Survey (YRBS) data collected during 1991-2011 from 45 states (N = 715,014) to examine MML effects, taking advantage of heterogeneity across states in MML status and design. Multiple logistic regression modeling was used to adjust for state and year effects, and youth demographics.
Results: Unadjusted analyses found that MMLs were associated with higher rates of adolescent past-30-day marijuana use (odds ratio [OR] = 1.08, 95% confidence interval, [(CI) = 1.03,1.13]) and heavy marijuana use (OR = 1.12, [CI = 1.05,1.21]). However, analyses adjusting for state/year effects found a 7% lower odds of use (OR = 0.99, [CI = 0.98,0.999]) and no difference in heavy use. In the adjusted models, years since MML enactment (OR = 0.93, [CI = 0.86,0.99]) and MML inclusion of more liberalized provisions (OR = 0.98, [CI = 0.96,0.998]) were associated with slightly lowered odds of past-30-day marijuana use. Conversely, allowance for ≥2.5 usable marijuana ounces was associated with higher past-30-day marijuana use odds (OR = 1.21, [CI = 1.09,1.34]) and a voluntary vs. mandatory patient registration with higher odds of both past-30-day use (OR = 1.41, [CI = 1.28,1.56]) and heavy use (OR = 1.23, [CI = 1.08,1.40]).
Conclusions: MML enactment, years since enactment, and inclusion of more liberalized provisions were not associated with increased adolescent marijuana use in this dataset after adjusting for state and year effects; however, higher possession limits and a voluntary registration were. It is possible that state norms are the impetus for MML enactment.
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Hermine Maes et al.
Behavior Genetics, November 2016, Pages 735–741
Abstract:
Using Swedish nationwide registry data, the authors investigated the correlation of genetic and environmental risk factors in the etiology of drug abuse as ascertained from medical and criminal registries by modeling twin and sibling data. Medical drug abuse was defined using public inpatient and outpatient records, while criminal drug abuse was ascertained through legal records. Twin, full and half sibling pairs were obtained from the national twin and genealogical registers. Information about sibling pair residence within the same household was obtained from Statistics Sweden. Standard bivariate genetic structural equation modeling was applied to the population-based data on drug abuse ascertained through medical and crime registries, using OpenMx. Analyses of all possible pairs of twins (MZ: N = 4482; DZ: N = 9838 pairs), full- (N = 1,278,086) and half-siblings (paternal: N = 7767; maternal N = 70,553) who grew up together suggested that factors explaining familial resemblance for drug abuse as defined through medical or criminal registries were mostly the same. Results showed substantial heritability and moderate contributions of shared environmental factors to drug abuse; both were higher in males versus females, and higher for drug abuse ascertained through criminal than medical records. Because of the low prevalence of both assessments of drug abuse, having access to population data was crucial to obtain stable estimates. Using objective registry data, the authors found that drug abuse — whether ascertained through medical versus criminal records — was highly heritable. Furthermore, shared environmental factors contributed significantly to the liability of drug abuse. Genetic and shared environmental risk factors for these two forms of drug abuse were highly correlated.
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A Structural Model of the Retail Market for Illicit Drugs
Manolis Galenianos & Alessandro Gavazza
American Economic Review, forthcoming
Abstract:
We estimate a model of illicit drugs markets using data on purchases of crack cocaine. Buyers are searching for high-quality drugs, but they determine drugs’ quality (i.e., their purity) only after consuming them. Hence, sellers can rip off first-time buyers or can offer higher-quality drugs to induce buyers to purchase from them again. In equilibrium, a distribution of qualities persists. The estimated model implies that if drugs were legalized, in which case purity could be regulated and hence observable, the average purity of drugs would increase by approximately 20 percent and the dispersion would decrease by approximately 80 percent. Moreover, increasing penalties may raise the purity and affordability of the drugs traded by increasing sellers’ relative profitability of targeting loyal buyers versus first-time buyers.
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It’s Complicated: Examining Smokers’ Relationships With Their Cigarette Brands
Sarah Johnson, Blair Coleman & Carol Schmitt
Psychology of Addictive Behaviors, forthcoming
Abstract:
Despite increased restrictions and taxes, decreased social acceptability, and widespread awareness of the harms of tobacco use, many in the U.S. continue to smoke cigarettes. Thus, understanding smokers’ attitudes and motivations remains an important goal. This study adopts the consumer psychology concept of brand relationship to provide a new lens through which to examine smokers’ attitudes about their cigarette use. Twelve focus groups (N = 143) were conducted with adult cigarette smokers from September to November, 2013. Using a semistructured moderator guide and “top of mind” worksheets, the discussion examined participants’ attitudes toward (a) their own cigarette brand and (b) tobacco companies in general. Data were coded and analyzed following principles of thematic analysis. Adult smokers reported positive attitudes toward their cigarette brand, as their brand was strongly associated with the positive experience of smoking (e.g., satisfying craving and relief from withdrawal). In contrast, thinking about tobacco companies in general evoked negative reactions, revealing overwhelmingly negative attitudes toward the industry. Findings reveal a complicated relationship between smokers and their cigarette brand: simultaneously embracing their cigarettes and rejecting the industry that makes them. Taken together, these data suggest smokers maintain largely positive brand relationships, diverting negative feelings about smoking toward the tobacco industry. Finally, they highlight the synergy between branding and the subjective smoking experience, whereby positive brand attitudes are reinforced through withdrawal relief. Ultimately, this information could inform a more complete understanding of how smokers interpret and respond to tobacco communications, including marketing from their brand.
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Angela Stevens et al.
Addictive Behaviors, February 2017, Pages 147–153
Abstract:
Extant literature has established a strong relation between individual differences in “impulsivity” and alcohol consumption. However, the relation between “impulsivity,” intentions-to-drink, and alcohol consumption has remained understudied. As a part of a larger study, 77 participants (60.5% female, 76.3% White, M age = 20.8) completed 10 days of daily diary reports regarding their intention to use alcohol and alcohol consumption. Hierarchical linear modeling (HLM) was used to estimate within-person relations between intentions-to-drink and subsequent alcohol use. All models were adjusted for participant age, biological sex, and day of the week. Results showed a strong positive association between daily intention to consume alcohol and self-reported alcohol use (β = 0.50, p < 0.01). Importantly, tests of interactions indicated that individuals higher in impulsivity were not significantly more likely to engage in unplanned drinking. Multilevel mediation analyses indicated significant indirect effects between impulsivity-like constructs, including positive urgency, lack-of-planning, and self-report delay discounting, and reported daily alcohol consumption via higher overall (i.e., between-person) levels of intentions-to-drink; that is, individuals who reported higher levels of these impulsivity-related constructs were more likely to intend to drink across the 10-days and, in turn, consumed more alcohol. Findings from the study suggest that treatment providers could address drinking intentions among individuals higher in impulsivity and work to establish potential replacement behaviors to reduce alcohol consumption in this population.