Rationale
In a previous study, investigating choice between heroin and a non-drug alternative in animals and reductions in income (i.e., choices/day) caused the percentage of income spent on heroin ...to progressively decrease. In contrast, another study found that humans with opioid use disorder spent the majority of their income on heroin even though they had little income. Comparison of these two studies suggests that the seemingly conflicting results could be explained by differences in the underlying economy types of the choice alternatives.
Objective
The present experiment tested the hypothesis that the effect of income changes on choice between heroin and a non-drug alternative depends on economy type.
Methods
Rats chose between heroin and saccharin under three income levels. For the Closed group, the choice session was the only opportunity to obtain these reinforcers. For the Heroin Open group and the Saccharin Open group, choice sessions were followed by 3-h periods of unlimited access to heroin or saccharin, respectively.
Results
As income decreased, the Closed and Heroin Open groups, but not the Saccharin Open group, spent an increasingly greater percentage of income on saccharin than on heroin. The Saccharin Open group, compared to the other groups, spent a greater percentage of income on heroin as income decreased.
Conclusions
Results confirm that the effects of income and economy type can interact and this may explain the apparently discrepant results of earlier studies. More generally, findings suggest that situations where heroin choice has little consequence for consumption of non-drug alternatives may promote heroin use.
To identify latent classes of positive coping behaviors during the COVID-19 pandemic and examine associations with alcohol-related and mental health outcomes across participants with and without a ...history of alcohol use disorder (AUD).
Baseline data from 463 participants who were enrolled in the NIAAA COVID-19 Pandemic Impact on Alcohol (C19-PIA) Study were analyzed. Latent class analysis (LCA) was applied to five positive coping behaviors during COVID-19: taking media breaks, taking care of their body, engaging in healthy behaviors, making time to relax, and connecting with others. Latent class differences and the moderating role of history of AUD on six alcohol-related and mental health outcomes were examined using multiple regression models.
LCA revealed two latent classes: 83.4% High Positive Coping and 16.6% Low Positive Coping. Low Positive Coping was associated with higher levels of perceived stress, anxiety symptoms, and loneliness. A history of AUD was consistently associated with higher levels of alcohol-related and mental health outcomes. Significant interactions between Coping Latent Classes and history of AUD indicated that the associations of Low Positive Coping with problematic alcohol use, depressive symptoms, and drinking to cope motives were either stronger or only significant among individuals with a history of AUD.
Individuals with a history of AUD may be particularly vulnerable to depressive symptoms and alcohol-related outcomes, especially when they do not utilize positive coping strategies. The promotion of positive coping strategies is a promising avenue to address alcohol-related and mental health problems during a public health crisis and warrants future research.
It has been suggested that menthol increases exposure to harmful elements of smoking and makes smoking more rewarding, easier to initiate, and harder to quit. Isolating the direct effects of menthol ...is challenging as African American (AA) race and menthol preference are highly overlapping. This study evaluated smoking behavior and subjective responses among a balanced sample of AA and white menthol and non-menthol smokers. In addition, smoking topography (ST) was compared to naturalistic smoking (NS) and interactions with menthol and race were explored.
Smokers (N = 100) smoked and rated their preferred brand of cigarettes via ST or NS during two laboratory visits (counterbalanced).
Controlling for baseline differences among the groups (eg, nicotine dependence), menthol smokers took shorter and smaller puffs and AA smokers took longer puffs, but there were no differences in total puff volume, carbon monoxide, or other ST parameters. Menthol smokers reported greater urge reduction and lower sensory stimulation. The smoking method (ST vs. NS) had no effects on smoking behavior or exposure. Cigarettes smoked via ST were rated stronger. Differences in satisfaction based on the smoking method interacted with race and menthol status. Ratings of aversion differed by race and menthol status.
Menthol was not associated with increased smoke exposure or reward (except for urge reduction). ST caused minimal experimental reactivity relative to NS. Additional research that isolates the effects of menthol and examines potential interactive effects with race and other variables is needed to better understand its role in smoking-related health disparities.
Menthol and non-menthol smokers differed on some demographic variables and menthol preference was associated with greater nicotine dependence and greater urge reduction after smoking. Menthol was not associated with greater smoke exposure. Future research that investigates the unique risks associated with menthol and examines potential interactive effects with race and other related variables is warranted to better understand the role of menthol in smoking-related health disparities.
Background: Hyperkatifeia describes amplified emotional and motivational withdrawal due to addiction-related sensitization of brain-stress-systems. Hyperkatifeia has been proposed as a target for ...addiction treatment development. However, translation of basic research in this area will require new tools designed to measure hyperkatifeia and related phenomena outside of laboratory settings.Objectives: We define a novel concept, withdrawal interference, and introduce a new tool - the Withdrawal Interference Scale (WIS) - which measures the impact of withdrawal on daily life among individuals with OUD or AUD.Methods: Described are the combined results of three separate cross-sectional studies. The structural validity, convergent validity, construct validity, trans-diagnostic (AUD/OUD) configural, metric, and scalar invariance, internal consistency, and composite reliability of WIS was tested among three independent samples of 1) treatment-seeking adults with OUD (n = 132), 2) treatment-seeking adults with AUD (n = 123), and 3) non-treatment-seeking adults with OUD (n = 140). Males numbered 218 and females were 163.Results: WIS exhibited structural validity (1 factor), convergent validity (average variance extracted .670-.676), construct validity, trans-diagnostic configural (χ2/df = 2.10), metric (Δχ2 = 5.70, p = .681), and scalar invariance (Δχ2 = 12.34, p = .338), internal consistency (α .882-928), and composite reliability (.924-.925).Conclusion: These results suggest WIS is a valid and reliable instrument for measuring withdrawal-related life disruption in AUD and OUD. Further, given our findings of transdiagnostic measurement invariance, WIS scores of individuals with AUD and OUD can be meaningfully compared in future statistical analyses.
The COVID-19 pandemic has influenced people's lives in diverse ways. The authors utilized latent class analysis (LCA), a person-centered approach, to examine distinct patterns of COVID-related ...stressors and their associations with alcohol-related, mental health, and quality of life outcomes. Participants were 463 adults who completed the baseline assessment of the National Institute on Alcohol Abuse and Alcoholism COVID-19 Pandemic Impact on Alcohol Study from June 2020 to January 2022. Using cross-sectional data, three analytic methods (continuous sum score, categorical grouping, and LCA) were applied to model 17 COVID-related stressors. Regression analyses indicated higher COVID-related stress and endorsement of four or more COVID-related stressors were generally associated with worse health-related outcomes. LCA revealed four classes: Class 1: Minimal COVID-Related Impact (51.6%); Class 2: Work Interruptions (24.8%); Class 3: Family/Friends Affected by COVID (14.5%); and Class 4: Serious Financial Stress (9.1%). Racial/ethnic minorities were more likely to be in Class 3, whereas individuals with more years of education and higher income were less likely to be in Class 4. Individuals with a history of alcohol use disorder were more likely to be in Classes 2 and 4. Compared with Class 1, Class 4 reported highest levels of perceived stress, problematic alcohol use, anxiety symptoms, depressive symptoms, alcohol craving, loneliness, drinking to cope, and lowest levels of physical, psychological, social, and environment quality of life. COVID-related stressors disproportionately affected minority and vulnerable groups. Individuals who experienced multiple financial stressors had the greatest risk for negative health-related outcomes and may benefit from holistic interventions and community outreach.
Public Significance Statement
This study examined different types of stressors that people encountered during the COVID-19 pandemic such as work interruptions, financial stress, and knowing someone infected with COVID-19. Individuals who experienced multiple financial stressors made up a small minority but had higher mental health and alcohol-related problems, as well as lower quality of life. This group of individuals may benefit from holistic interventions and community outreach.
The present study used a rat choice model to test how cocaine or heroin economically interacted with two different nondrug reinforcers along the substitute-to-complement continuum. In Experiment 1, ...the nondrug alternative was the negative reinforcer timeout-from-avoidance (TOA)-that is, rats could press a lever to obtain a period of safety from footshock. One group of rats chose between cocaine and TOA and another group chose between heroin and TOA. The relative prices of the reinforcers were manipulated across phases while controlling for potential income effects. When cocaine was the reinforcer, rats reacted to price changes by increasing their allocation of behavior to the more expensive option, thereby maintaining relatively proportional intake of cocaine and TOA reinforcers across prices, suggesting these reinforcers were complements here. In contrast, when heroin became relatively cheap, rats increased allocation of income to heroin and decreased allocation of income to TOA, suggesting that heroin substituted for safety. Additionally, rats were willing to accept more footshocks when heroin was easily available. In Experiment 2, the nondrug alternative was saccharin, a positive reinforcer. Heroin and saccharin were complements, but there was no consistent effect of price changes on the allocation of behavior between cocaine and saccharin. As a model of the processes that could be involved in human drug use, these results show that drug-taking behavior depends on the type of drug, the type of nondrug alternative available, and the prices of both.
Public Health Significance
The present study used a rat model to test how the availability of different nondrug alternatives impact the taking of cocaine and heroin. The results could help in understanding factors that promote or reduce the use of these drugs in humans.
According to behavioral economics, reinforcer value should be lower in an open economy than in a closed economy. An animal model was used to determine how economy type affected the value of heroin ...and saccharin. In a first phase, separate groups of rats worked for heroin or saccharin. The price of these reinforcers increased over sessions. For rats in the open heroin or open saccharin economies, the work period of each session was followed by a postwork period where a cheaper source of heroin or saccharin was available for three hours. For rats in the closed economies, the work period was their only opportunity to obtain the reinforcer. Rats in the open saccharin economy worked less hard to defend consumption of saccharin as price increased than rats in the closed saccharin economy. That is, opening the saccharin economy reduced its essential value. In contrast, economy type had no effect on heroin's essential value. In a second phase, rats were allowed to choose between heroin and saccharin. The majority of rats strongly preferred saccharin over heroin regardless of economy type. The finding that economy type changed the essential value of saccharin, but not heroin, adds to previous findings suggesting that the value of drug reinforcers is unaffected by future drug availability. The difference in effect of economy type on drug versus nondrug reinforcers could be relevant to addiction.
Public Health Significance
This study investigated, within an animal model, factors that might contribute to opioid addiction. Results indicated that, unlike responding for nondrug rewards, current heroin-seeking behavior was not diminished by future availability of the reward. This difference between heroin and nondrug rewards could be relevant for understanding why addiction to opioids develops.
It has recently been proposed that the intermittent access (IntA) drug self-administration procedure better produces behavioral changes relevant to addiction than the long access (LgA) procedure. In ...this version of the IntA procedure, the drug is made available for a 5-min period during each half hour of a 6-h session. In contrast, on the LgA procedure, the drug is available continuously for 6 h. Previous studies have found that IntA drug self-administration produces greater drug motivation, measured by increased progressive ratio breakpoints, than LgA self-administration. It has been hypothesized that this effect is due to the rapid, “spiking” brain levels of the drug, and consequent neuroadaptations, experienced by rats during IntA sessions. However, no study has compared the effects of IntA versus LgA training on reinforcer motivation when using a non-drug reinforcer. The present study compared motivation for a saccharin reinforcer after IntA or LgA training. In Experiment 1, separate groups of rats lever-pressed for saccharin on the IntA or LgA procedures. In Experiment 2, a within-subjects design was used where rats pressed one lever on the IntA procedure and another lever on the LgA procedure for saccharin. In both experiments, IntA training produced greater breakpoints than LgA training. As no drug was used here, spiking drug levels could not have been responsible for the increased saccharin motivation observed after IntA training. Instead, it is proposed that differences in stimulus-reinforcer associations learned during IntA versus LgA training may be responsible for the effect. Future research is needed to determine the extent to which such learning factors may contribute to the increased motivation observed after IntA training with drug reinforcers.
•A unique sample with individuals with and without alcohol use disorder was used.•Loneliness increased from before to during the pandemic for all groups.•Social support decreased among healthy ...controls and those who sought prior AUD treatment.•Loneliness mediated the associations between history of AUD and mental health outcomes.•Addressing loneliness among individuals with AUD may help alleviate burden of mental health challenges.
This study examined the effects of alcohol use disorder (AUD) and treatment history on changes in loneliness, social support, and mental health symptoms from before to during the pandemic, and tested loneliness and social support as mediators of the AUD-mental health associations. Participants (n = 427) enrolled in the NIAAA COVID-19 Pandemic Impact on Alcohol Study were categorized into three groups: healthy control (62.3%), nontreatment AUD (14.1%), and treatment AUD (23.7%). Multilevel generalized linear models were conducted to examine changes in loneliness, social support, and mental health symptoms by group. Path analyses tested the mediating roles of loneliness and social support. Loneliness increased during the pandemic, especially in the nontreatment AUD group. Social support decreased in the healthy control and AUD treatment group. Anxiety and depressive symptoms increased in the nontreatment AUD group. Individuals with a history of AUD regardless of treatment history reported greater loneliness, which was linked to higher anxiety and depressive symptoms. Loneliness, but not social support, mediated the AUD-mental health associations. Psychosocial interventions aimed at increasing positive social engagement among individuals with AUD may help alleviate feelings of loneliness and mitigate mental health symptoms. Study findings can also help improve preparedness for future public health crises.
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