Racial inequities and addiction research

What accounts for variation across racial and ethnic groups in drug use and harms related to substance use? While explanatory mechanisms for racial and ethnic disparities include differential access to and use of health services, a myriad of other factors, including racism and historical trauma, contribute to drug-related disparities. Furthermore, the addiction scientific workforce, like the full biomedical research enterprise, lacks diversity. This deficit undercuts U.S. scientific leadership and is a major challenge for the field. To address these entrenched problems, the National Institute on Drug Abuse (NIDA) is prioritizing research on health disparities and supporting multiple efforts to enhance scientific workforce diversity. Studies on substance use trends and emerging threats must measure disparities and track progress in reducing disparities, but also acknowledge the limitations of race and ethnicity-based data. Researchers must take the bold step of proposing studies that elucidate causal mechanisms which have the potential to be ameliorated by novel policies and practices. Critically, the impact of racism on all aspects of the substance use trajectory must be assessed to better tailor prevention, harm reduction, treatment, and recovery-support interventions to the specific circumstances of those who need them. Particular attention should be given to people who are incarcerated, who are experiencing homelessness, and who have a history of adverse childhood experiences. Training the next generation of the addiction science workforce needs to address structural barriers to participation with partnerships between funders, such as NIDA, and grantee organizations.

Sex- and age-specific effects on the development of addiction and compulsive-like drinking in rats

BACKGROUND

Biological factors are known to influence disease trajectories and treatment effectiveness in alcohol addiction and preclinical and clinical evidence suggests that sex is an important factor influencing disease dynamics in alcohol dependence. Another critical factor is age at first intoxicating drink, which has been identified as a risk factor for later alcohol binging. Preclinical research allows prospective monitoring of rodents throughout the lifespan, providing very detailed information that cannot be acquired in humans. Lifetime monitoring in rodents can be conducted under highly controlled conditions, during which one can systematically introduce multiple biological and environmental factors that impact behaviors of interest.

METHODS

Here, we used the alcohol deprivation effect (ADE) rat model of alcohol addiction in a computerized drinkometer system, acquiring high-resolution data to study changes over the course of addictive behavior as well as compulsive-like drinking in cohorts of adolescent vs. adult as well as male vs. female rats.

RESULTS

Female rats drank more alcohol than male rats during the whole experiment, drinking much more weak alcohol (5%) and similar amounts of stronger alcohol solutions (10%, 20%); female rats also consumed more alcohol than male rats during quinine taste adulteration. Increased consumption in females compared to males was driven by larger access sizes of alcohol. Differences in circadian patterns of movement were observed between groups. Early age of onset of drinking (postnatal day 40) in male rats had surprisingly little impact on the development of drinking behavior and compulsivity (quinine taste adulteration) when compared to rats that started drinking during early adulthood (postnatal day 72).

CONCLUSIONS

Our results suggest that there are sex-specific drinking patterns, not only in terms of total amount consumed, but specifically in terms of solution preference and access size. These findings provide a better understanding of sex and age factors involved in the development of drinking behavior, and can inform the preclinical development of models of addiction, drug development and exploration of options for new treatments.

Drug dependence as a split object: Trajectories of neuroscientification and behavioralization at the Max Planck Institute of Psychiatry

Today, drug dependence is often understood as a "brain disease" and as an indication for behavioral therapy. In this article, I trace the historical development of the notions of drug dependence as a neuronal and behavioral problem in the local research context of the Max Planck Institute of Psychiatry in Munich, Germany. Focusing on the period from the 1950s to the 1980s, I argue that the neuroscientific and behaviorist understanding of "dependence" had two different trajectories that were yoked together under the same institution of self-proclaimed basic research: (a) the neuroscientific notion derived from an older toxicological approach to drug effects that was then accompanied by biochemical methods from the 1950s onwards, and neurochemical approaches from the 1960s and 1970s; and (b) the behaviorist notion had predecessors in psychotherapeutic approaches to addiction that emerged in the 1950s and took a psychodynamic orientation at the Institute. When the Institute positioned itself as a basic research establishment and developed a unified structure during the 1960s, these psychodynamic approaches were excluded for being "too applied." Soon afterward, behaviorist psychotherapeutic approaches to drug dependence emerged in the 1970s, emphasizing their foundation in basic research. Even though neuroscientific and behaviorist notions had some overlaps through the use of animal experimentation and by referring to basic research, researchers using the two approaches remained separate in their respective units during the time period under analysis. When conceptualizing the local scientific occupation with "drug dependence," I apply here the history of science concept of a "split object." Like the "boundary object," the split object is plastic enough to adapt to local conditions and robust enough to maintain its genuine identity. Compared with the boundary object, however, the split object does not invite scientific collaboration. It does, nonetheless, enable epistemic coexistence under a common institutional goal.

Using primary care databases for addiction research: An introduction and overview of strengths and weaknesses

Primary care databases extract and combine routine data from the electronic patient records of various participating practices on a regular basis. These databases can be used for innovative and relevant addiction research, but such use requires a thorough understanding of how data were originally collected and how they need to be processed and statistically analysed to produce sound scientific evidence. The aims of this paper are therefore to (1) make a case for why primary care databases should be considered more frequently for addiction research; (2) provide an overview of how primary care databases are constructed; (3) highlight important methodological and statistical strengths and weaknesses of using primary care databases for research; and (4) give practical advice about how a researcher can get access to databases. Three major primary care databases from the UK serve as examples: Clinical Practice Research Datalink (CPRD), The Health Improvement Network (THIN), and QResearch.

Analysis of Opioid Poisoning in Medically Underserved Rural Areas: An Evaluation of International Statistical Classification of Diseases Codes from the State of South Dakota

Background

Rural hospitals and patient population tend to be medically underserved. The states with more rural population dispensed the most opioids per person in the last 10 years. We aimed to explore if rurality contributed to the likelihood of higher opioid adversity and how it affected substance-use rehabilitation in federally designated Medically Underserved Areas (MUAs).

Methods

We analyzed data dispensed by the South Dakota Department of Health (DOH) on opioid-led poisoning International Classification of Disease (ICD) codes that were active within the state in the last decade. After locating MUA rural and partially rural counties, we cross profiled the counties to the state datasets. Assessments were conducted using the PROC SURVEY methods in SAS version 9.3 (SAS Institute) and checked for multicollinearity with the Belsley-Kuh-Welsch technique. Finally, we used the American Hospital Association (AHA) database for analyzing substance use rehabilitation availability on per hospital basis.

Results

The chi-square statistic for comparing opioid codes against non-opioid codes distributed among three categories, rural, non-rural, and partially rural was significant at the limit of p <0.05. 81.134% of opioid-led poisoning codes were activated in a rural county. Only four hospitals had substance-use rehabilitation, three of which were in a non-rural area. More people from the teenage and early-adulthood years (10-19) were prone to opioid usage.

Conclusions

Rural counties in South Dakota were more likely to dispense opioid care and not have access to rehabilitation. We also found that as the opioid dispensing rate at hospitals within a state decreased as the state had less rural counties. Introducing public programs to train more physicians and cutting down cost of non-opioid based care may lower opioid distribution and increase rehabilitation options in rural hospitals.

Nicotine gum enhances visual processing in healthy nonsmokers

OBJECTIVE

The main purpose of this study was to investigate the isolated effects of nicotine on visual processing, namely contrast processing.

METHODS

Thirteen participants, aged 18-40 years, were enrolled in this double blind, randomized and pilot controlled trial involving nicotine gum administration (placebo, 2-mg and 4-mg doses). The participants' instruction was to detect the location of vertical gratings (0.2; 1.0; 3.3; 5.7; 8.8; 13.2 and 15.9 cycles per degree) when it was presented either left or right on the monitor screen. A repeated multivariate analysis of variance was conducted to analyse the results for the visual processing tasks. Bayesian analyses were also carried out considering maximum robustness to avoid bias.

RESULTS

The findings that nicotine gum administration resulted in better contrast discrimination when compared to placebo gum (p < .001). More specifically, the 4-mg resulted in better visual sensitivity when compared to the 2-mg (p < .01) and the placebo (p < .001) gum. Demographic data were not related to the outcomes.

CONCLUSIONS

These data bring the need for support the findings. If proved, it is possible that nicotine, in small doses, can have a potential therapeutic use for those populations with low vision.

TRIAL REGISTRATION NUMBER

RBR-46tjy3.

Quantifying the impact of partial measurement invariance in diagnostic research: An application to addiction research

Establishing measurement invariance, or that an instrument measures the same construct(s) in the same way across subgroups of respondents, is crucial in efforts to validate social and behavioral instruments. Although substantial previous research has focused on detecting the presence of noninvariance, less attention has been devoted to its practical significance and even less has been paid to its possible impact on diagnostic accuracy. In this article, we draw additional attention to the importance of measurement invariance and advance diagnostic research by introducing a novel approach for quantifying the impact of noninvariance with binary items (e.g., the presence or absence of symptoms). We illustrate this approach by testing measurement invariance and evaluating diagnostic accuracy across age groups using DSM alcohol use disorder items from a public national data set. By providing researchers with an easy-to-implement R program for examining diagnostic accuracy with binary items, this article sets the stage for future evaluations of the practical significance of partial invariance. Future work can extend our framework to include ordinal and categorical indicators, other measurement models in item response theory, settings with three or more groups, and via comparison to an external, "gold-standard" validator.

Supporting the role of community members employed as research staff: Perspectives of community researchers working in addiction research

Community researchers are laypersons who conduct research activities in their own communities. In addiction and HIV research, community researchers are valued for their insider status and knowledge. At the same time, their presence on the research team raises concerns about coercion and confidentiality when community researchers and participants know each other personally, and the work of navigating between the worlds of research and community leads to moral distress and burnout for some community researchers. In this paper, we draw upon the concept of 'moral experience' to explore the local moral worlds of community researchers in the context of addiction research. In February and March 2010, we conducted focus groups with 36 community researchers employed on community-based addiction studies in the United States to elicit perspectives on ethical and moral challenges they face in their work and insights on best practices to support their role in research. Community researchers described how their values were realized or thwarted in the context of research, and their strategies for coping with shifting identities and competing priorities. They delineated how their knowledge could be used to inform development of research protocols and help principal investigators build and maintain trust with the community researchers on their teams. Our findings contribute to current understandings of the moral experiences of community members employed in research, and inform policies and practices for the growing field of community-engaged research. Funders, research organizations, and research ethics boards should develop guidelines and standards to ensure studies have key resources in place to support community researchers and ensure quality and integrity of community-engaged work. Investigators who work with community researchers should ensure channels for frontline staff to provide input on research protocols and to create an atmosphere where challenges and concerns can be openly and safely discussed.

Confounding in longitudinal studies in addiction treatment research

Background: The effectiveness of treatment for people with substance use disorders is usually examined using longitudinal cohorts. In these studies, treatment is often considered as a time-varying exposure. The aim of this commentary is to examine confounding in this context, when the confounding variable is time-invariant and when it is time-varying. Method: Types of confounding are described with examples and illustrated using path diagrams. Simulations are used to demonstrate the direction of confounding bias and the extent that it is accounted for using standard regression adjustment techniques. Results: When the confounding variable is time invariant or time varying and not influenced by prior treatment, then standard adjustment techniques are adequate to control for confounding bias, provided that in the latter scenario the time-varying form of the variable is used. When the confounder is time varying and affected by prior treatment status (i.e. it is a mediator of treatment), then standard methods of adjustment result in inconsistency. Conclusions: In longitudinal cohorts where treatment exposure is time varying, confounding is an issue which should be considered, even if treatment exposure is initially randomized. In these studies, standard methods of adjustment may result be inadequate, even when all confounders have been identified. This occurs when the confounder is also a mediator of treatment. This is a likely scenario in many studies in addiction.

Scientific writing seminar for early-stage investigators in substance abuse research

BACKGROUND

There is little information on how to increase the scientific writing productivity of early-stage investigators in the addictions field. A scientific writing seminar is presented in this article, aiming to encourage manuscript writing and dissemination of addiction research, and outcomes are reported for 14 years of the seminar.

METHODS

In 14 years, there were 113 postdoctoral fellow enrollments in a 6-month writing seminar. Records of submission and publication rates of manuscripts were collected for 14 cohorts.

RESULTS

Of the 113 participant enrollments, 97 (86%) submitted a manuscript for publication, and 87 participants (77%) published their manuscript.

CONCLUSIONS

A scientific writing seminar may benefit writing productivity, but more research is needed to compare this training model with other existing models.