Is addiction a brain disease? A plea for agnosticism and heterogeneity

Integrated and collaborative care across the spectrum of alcohol-associated liver disease and alcohol use disorder

The public health impact of alcohol-associated liver disease (ALD), a serious consequence of problematic alcohol use, and alcohol use disorder (AUD) is growing, with ALD becoming a major cause of alcohol-associated death overall and the leading indication for liver transplantation in the United States. Comprehensive care for ALD often requires treatment of AUD. Although there is a growing body of evidence showing that AUD treatment is associated with reductions in liver-related morbidity and mortality, only a minority of patients with ALD and AUD receive this care. Integrated and collaborative models that streamline both ALD and AUD care for patients with ALD and AUD are promising approaches to bridge this treatment gap and rely on multidisciplinary and interprofessional teams and partnerships. Here, we review the role of AUD care in ALD treatment, the effects of AUD treatment on liver-related outcomes, the impact of comorbid conditions such as other substance use disorders, obesity, and metabolic syndrome, and the current landscape of integrated and collaborative care for ALD and AUD in various treatment settings. We further review knowledge gaps and unmet needs that remain, including the role of precision medicine, the application of harm reduction approaches, the impact of health disparities, and the need for additional AUD treatment options, as well as further efforts to support implementation and dissemination.

Heterogeneity in choice models of addiction: the role of context

RATIONALE

Theories of addiction guide scientific progress, funding priorities, and policy development and ultimately shape how people experiencing or recovering from addiction are perceived and treated. Choice theories of addiction are heterogenous, and different models have divergent implications. This breeds confusion among laypeople, scientists, practitioners, and policymakers and reduces the utility of robust findings that have the potential to reduce the global burden of addiction-associated harms.

OBJECTIVE

Here we differentiate classes of choice models and articulate a novel framing for a class of addiction models, called contextual models, which share as a first principle the influence of the environment and other contextual factors on behavior within discrete choice contexts.

RESULTS

These models do not assume that all choice behaviors are voluntary, but instead that both proximal and distal characteristics of the choice environment-and particularly the benefits and costs of both drug use and non-drug alternatives-can influence behavior in ways that are outside of the awareness of the individual. From this perspective, addiction is neither the individual's moral failing nor an internal uncontrollable urge but rather is the result of environmental contingencies that reinforce the behavior.

CONCLUSIONS

Contextual models have implications for guiding research, practice, and policy, including identification of novel target mechanisms while also improving existing interventions.

Soul, body and mental health - applying Rabbi Moshe de Maimon's philosophy to the contemporary phenomenon of drug addiction

In modern psychiatry, drug addiction is considered as mainly a mental disorder and a brain disease problem, of complex aetiology. In addition, drug addiction has been characterized as a loss of willpower or akrasia, and even a sin. In this essay, I analyse Maimonides' (Rambam's) treatises More Ha-Nevuchim (Guide for the Perplexed) and Shemona Perakim (The Eight Chapters). He asserts that the soul is one, but has many different faculties (functions) and is intrinsically linked to the body. I argue that drug addiction is a psychological, social-moral deviance, as well as straying from God's path. Addiction is a disorder of the soul and body. Consequently, healing should include social-moral guidelines as well as physical/bodily health.

The importance of choice and agency in animal models of addiction

The aim of this short commentary is twofold. First, it uncovers and outlines in broad strokes a historical, albeit oft-overlooked, trend toward a growing place for choice and agency in the design of animal models of addiction. Next, it tries to draw from this historical trend some perspectives and implications for future research.

(Mis)understanding alcohol use disorder: Making the case for a public health first approach

'Alcohol use disorder' (AUD) is used by several contemporary conceptualizations to identify, treat and prevent problems associated with alcohol use. Such conceptualizations encompass diagnostic classifications and broader frameworks for policy and practice. However, current AUD concepts are subject to multiple tensions and limitations in capturing and responding to the complex and heterogeneous nature of alcohol problems. Further, public understandings of alcohol problems are heavily divergent from professional AUD concepts and remain embedded within an 'alcoholism' master narrative in which disease model stereotypes come with multiple costs for prevention and 'recovery'. The persistence of a problematic 'alcoholism' paradigm reflects the coalescing of multiple forces including the cognitive appeal of reductionism, motives to stigmatize and 'other', and an over-emphasis on AUD as an individually located biomedical problem. Public misperceptions of AUD as a matter of the individual, the individual's essence, and misconceived notions of responsibility and control have been bolstered by industry interests and the ascension of neuroscience and genetics, in turn diverting attention from the importance of the environmental and commercial determinants of health and the effectiveness of under-utilized public health policies. We call for multiple stakeholders to support efforts to prioritize a public health first approach to advancing AUD research, policy and treatment in order to make significant advances in AUD prevention and treatment. We offer several recommendations to assist in shifting public understanding and scientific limitations in AUD concepts and responses.

Conflicting theories on addiction aetiology and the strengths and limitations of substance use disorder disease modelling

A lack of cross-disciplinary unanimity prevails within addiction research. Theories conceptualizing addiction through the three-stage brain disease model contest other theories that substance use disorder is of behavioural or genetic origin. The reverberations of this lack of consensus are noticeable throughout addiction research and within the foundations of disease modelling. The availability of methods to investigate substance use disorder are inconsistent and sometimes unrepresentative. This review discusses theories of addiction aetiology, available models for addiction research and the strengths and limitations of current practical experimental methods of study.

Should we promote alcohol problems as a continuum? Implications for policy and practice

The highly heterogeneous nature of alcohol use and problems has presented significant challenges to those attempting to understand, treat or prevent what is commonly termed alcohol use disorder (AUD). However, any attempts to capture this complex phenomenon, including the various current criterion of AUD, come with a number of limitations. One particular limitation has been how alcohol problems are represented or understood in ways which do not capture the broad spectrum of alcohol use and harms and the many potential routes to prevention, treatment, and recovery. One possible response to this has been proposed as more explicitly framing or conceptualizing a continuum model of alcohol use and harms. In this commentary, we attempt to identify the key implications of a continuum model for policy and practice, examining the historical and current context of alcohol problem classifications and models. We argue a continuum model of alcohol use and problems holds a number of advantages for advancing public health goals, but also some potential limitations, both of which require further examination.

Alcohol use disorder conceptualizations and diagnoses reflect their sociopolitical context

The present paper highlights how alcohol use disorder (AUD) conceptualizations and resulting diagnostic criteria have evolved over time in correspondence with interconnected sociopolitical influences in the United States. We highlight four illustrative examples of how DSM-defined alcoholism, abuse/dependence, and AUD have been influenced by sociopolitical factors. In doing so, we emphasize the importance of recognizing and understanding such sociopolitical factors in the application of AUD diagnoses. Last, we offer a roadmap to direct the process of future efforts toward the improved diagnosis of AUD, with an emphasis on pursuing falsifiability, acknowledging researchers' assumptions about human behavior, and collaborating across subfields. Such efforts that center the numerous mechanisms and functions of behavior, rather than signs or symptoms, have the potential to minimize sociopolitical influences in the development of diagnostic criteria and maximize the treatment utility of diagnoses.

Should Reward Deficiency Syndrome (RDS) Be Considered an Umbrella Disorder for Mental Illness and Associated Genetic and Epigenetic Induced Dysregulation of Brain Reward Circuitry?

Reward Deficiency Syndrome (RDS) is defined as a breakdown of reward neurotransmission that results in a wide range of addictive, compulsive, and impulsive behaviors. RDS is caused by a combination of environmental (epigenetic) influences and DNA-based (genetic) neurotransmission deficits that interfere with the normal satisfaction of human physiological drives (i.e., food, water, and sex). An essential feature of RDS is the lack of integration between perception, cognition, and emotions that occurs because of (1) significant dopaminergic surges in motivation, reward, and learning centers causing neuroplasticity in the striato-thalamic-frontal cortical loop; (2) hypo-functionality of the excitatory glutamatergic afferents from the amygdala-hippocampus complex. A large volume of literature regarding the known neurogenetic and psychological underpinnings of RDS has revealed a significant risk of dopaminergic gene polymorphic allele overlap between cohorts of depression and subsets of schizophrenia. The suggestion is that instead of alcohol, opioids, gambling disorders, etc. being endophenotypes, the true phenotype is RDS. Additionally, reward deficiency can result from depleted or hereditary hypodopaminergia, which can manifest as a variety of personality traits and mental/medical disorders that have been linked to genetic studies with dopamine-depleting alleles. The carrying of known DNA antecedents, including epigenetic insults, results in a life-long vulnerability to RDS conditions and addictive behaviors. Epigenetic repair of hypodopaminergia, the causative basis of addictive behaviors, may involve precision DNA-guided therapy achieved by combining the Genetic Addiction Risk Severity (GARS) test with a researched neutraceutical having a number of variant names, including KB220Z. This nutraceutical formulation with pro-dopamine regulatory capabilities has been studied and published in peer-reviewed journals, mostly from our laboratory. Finally, it is our opinion that RDS should be given an ICD code and deserves to be included in the DSM-VI because while the DSM features symptomology, it is equally important to feature etiological roots as portrayed in the RDS model.

From concepts to treatment: a dialog between a preclinical researcher and a clinician in addiction medicine

The debate surrounding the brain disease model and the associated questioning of the relevance of animal models is polarizing the field of addiction, and tends to widen the gap between preclinical research and addiction medicine. Here, we aimed at bridging this gap by establishing a dialog between a preclinical researcher and a clinician in addiction medicine. Our objective was to evaluate animal models and the neuroscientific conceptualization of addiction in light of alcohol or drug dependence and treatment in patients struggling with an addiction. We sought to determine how preclinical research influenced addiction medicine over past decades, and reciprocally, what can preclinical researchers learn from addiction medicine that could lead to more effective approaches. In this dialog, we talk about the co-evolution of addiction concepts and treatments from neuroscientific and medical perspectives. This dialog illustrates the reciprocal influences and mutual enrichment between the two disciplines and reveals that, although preclinical research might not produce new pharmacotherapies, it does shape the theoretical conceptualization of addiction and could thereby contribute to the implementation of therapeutic approaches.

Gambling Disorder and Stigma: Opportunities for Treatment and Prevention

Purpose of Review

Gambling disorder is among the most stigmatized mental health problems. More research is needed to understand the mechanisms that underlie this stigma and the effects of stigma-reduction interventions. This paper reviews extant literature on the stigma of gambling disorder and highlights evidence from this research and the broader mental illness stigma literature to help advance research on the prevention and reduction of gambling-related stigma.

Recent Finding

The public stigma of gambling disorder includes stereotypes of affected individuals as “greedy” and “irresponsible,” beliefs that affected individuals are to blame for their problems, and desire to avoid social contact with affected individuals. Stigmatizing attitudes held by the public are often internalized by individuals with gambling disorder, which leads to problem concealment, reduced treatment-seeking, and decreased self-esteem. Women with gambling disorder, as well as those with more severe gambling problems and who perceive greater stigma by the public, are most vulnerable to self-stigma. There is evidence that certain beliefs may underlie the stigmatization of gambling disorder, including beliefs about its causes. Contact- and education-based interventions show efficacy for the reduction of mental illness-related stigma more broadly; additional research is needed to determine the efficacy of various stigma reduction strategies for gambling disorder specifically.

Summary

Gambling disorder is highly stigmatized relative to other mental health problems, in part because it is viewed as more likely to be caused by controllable factors. Interventions that emphasize the biopsychosocial etiology of gambling disorder may help to prevent and reduce the blame and stigmatization of affected individuals. Structural stigma within domains such as legislation, healthcare, and the gambling industry, interventions to reduce self-stigma, stigma among mental health professionals, and the influence of culture on stigma and its reduction are critical issues for future research.

Dopamine signaling in the dorsomedial striatum promotes compulsive behavior

Compulsive behavior is a defining feature of disorders such as substance use disorders. Current evidence suggests that corticostriatal circuits control the expression of established compulsions, but little is known about the mechanisms regulating the development of compulsions. We hypothesized that dopamine, a critical modulator of striatal synaptic plasticity, could control alterations in corticostriatal circuits leading to the development of compulsions (defined here as continued reward seeking in the face of punishment). We used dual-site fiber photometry to measure dopamine axon activity in the dorsomedial striatum (DMS) and the dorsolateral striatum (DLS) as compulsions emerged. Individual variability in the speed with which compulsions emerged was predicted by DMS dopamine axon activity. Amplifying this dopamine signal accelerated animals' transitions to compulsion, whereas inhibition delayed it. In contrast, amplifying DLS dopamine signaling had no effect on the emergence of compulsions. These results establish DMS dopamine signaling as a key controller of the development of compulsive reward seeking.