Substance use disorders and addictions

Abstract

Substance Use Disorders (SUDs) and Addictions are a major public health concern, affecting people’s health and well-being at all ages. The intention behind this collection was to publish original research articles on SUDs and related addictions. These articles would address genetic, neurobiological, psychological, and environmental risk factors for the development of these disorders, as well as approaches to diagnosis and treatment. Thirteen articles covering a wide range of topics related to different SUDs and behavioral addictions, as well as human and animal studies from basic and clinical research, were received and have been summarized in this editorial. Each of the articles has made a significant contribution to our scientific understanding of addiction, with the potential to inform clinical applications. We hope that the findings revealed by this collection of articles, along with the broader efforts of the scientific and clinical communities around the world, will lead to the development of better tools and methods for preventing, diagnosing, and treating substance use disorders (SUD) and behavioral addictions.

Introduction

The American Psychiatric Association defines substance use disorders (SUD) as a complex condition in which there is uncontrolled use of a substance despite harmful consequences¹. On the other hand, the term drug addiction has been defined by the National Institute on Drug Abuse (NIDA) as a chronic, relapsing disorder characterized by compulsive drug seeking and use despite adverse consequences². According to the National Survey on Drug Use and Health (NSDUH), major substances and substance types include alcohol, tobacco, cannabis, cocaine, heroin, stimulants, opioids, hallucinogens, inhalants, tranquilizers, and sedatives. The term addiction, in general, not only encompasses compulsive substance use, but also includes various behavioral addictions such as internet addiction, sexual addiction, compulsive shopping, and food addiction³. Addictions, both drug and behavioral addictions, are a major public health concern, affecting people’s health and well-being at all ages, and the symptoms of SUD and related addictions can be physiological, behavioral, or cognitive in nature, and they can range from moderate to severe⁴. It is also known that SUDs and behavioral addictions tend to co-occur, and both are associated with mental health problems⁵.

This collection was intended to host original research articles on SUDs and behavioral addictions that would deal with genetic, neurobiological, psychological, and environmental risk factors for the development of these disorders, as well as with approaches to diagnosis and treatment. Thirteen articles covering a wide range of topics related to SUD and behavioral addictions, as well as human and animal studies and basic and clinical research, were received and have been summarized in this editorial.

The majority of the studies focused on alcohol use disorder. Pilhatsch et al.⁶ investigated the impact of the COVID-19 pandemic on trajectories of patients with severe alcohol use disorder (AUD) who were treated with disulfiram, and reported that during the pandemic, the number of treatment cancellations increased, while a tendency towards normalization of patient visits was observed after the peak of the pandemic. Another study by Tsamitros et al.⁷ examined a novel therapeutic approach to craving induction through virtual reality (VR) cue-exposure (CE) in patients with alcohol dependence in a rehabilitation setting. They found that craving was significantly correlated with cybersickness. This study established that craving can be induced through the VR-CE paradigm, a strategy that can be implemented in long-term rehabilitation of AUD patients. Carbia et al.⁸ examined the relationship between alcohol bias and inhibitory control using the Alcohol Hayling Task (AHT) and found that binge drinkers generated more alcohol-related words in drinking-context sentences, committed more errors, and displayed slower response times when inhibiting alcohol-related responses, highlighting the role of alcohol-related semantic networks in craving states among youth drinkers. A cross-sectional multicenter study by Kim et al.⁹ reported that depressive and anxiety symptoms were found to be significant mediators in the relationship between family support and alcohol relapse, underscoring the importance of family support and psychological care in preventing and managing alcohol consumption in patients with alcohol-associated liver disease who underwent liver transplantation. Further, a study by Chaudhary et al.¹⁰ found that a higher prevalence of alcohol and tobacco use, as well as addiction risk, was observed among the college students who had adverse childhood experiences (ACE) compared to non-exposed students, highlighting the need to integrate ACE-informed approaches into existing substance use prevention and intervention programs. In addition, a study by Porras-Perales et al.¹¹ examined the importance of cardiovascular risk assessment in cocaine use disorder (CUD) and AUD, by assessing cardiac troponins T (cTnT) and I (cTnI) as biomarkers of myocardial injury in patients with CUD and AUD during abstinence. The findings indicated distinct troponin alterations in CUD and AUD patients, even without cardiovascular diagnosis, underscoring the importance of cardiovascular risk assessment in addiction treatment. Furthermore, a neuroimaging study Wu et al.¹² found that patients with a family history exhibited significant alterations in the integrity of white matter in the right hippocampus compared to patients without a family history and healthy controls, indicating altered hippocampal microstructure in AUD patients with a familial risk.

Some of the studies investigated different substances in human participants. For example, a study by Tiwari et al.¹³ examined the role of social network dynamics in mediating opioid access and overdose deaths in the United States, using Facebook’s social connectedness index as a proxy for real-life social networks to measure deaths in social proximity. The findings supported evidence of positive social influence on opioid overdose deaths in US counties and provided a pathway for public health interventions informed by social network structures. Another study by Pilhatsch et al.¹⁴ investigated the long-term benefits of a specialised treatment programme called 'Mummy, Think of Me’ for pregnant women and young mothers with methamphetamine use disorder and found evidence for the effectiveness and sustainability of this novel treatment programme to catalyse behavioural change and to promote long-term abstinence in both pregnant and parenting mothers. Wang et al.¹⁵ examined the effects of consuming different classes of drugs, such as anesthetics, psychotropics, and mixed consumption, on the balance and reaction times of abstinent women. Results showed that anesthetics impair dynamic balance more than psychotropic drugs, with users of mixed drugs falling in between the two groups. Users of psychotropic drugs demonstrated superior static balance and quicker reaction times than anesthetic users, while mixed drug users showed a moderate effect. These findings could inform interventions for the rehabilitation of various substance use disorders.

Other studies explored various types of addiction and related concepts. For instance, Gan et al.¹⁶ examined brainrot, a term referring to excessive, repetitive, and often compulsive use of low-quality digital media, and reported a complex interaction among brainrot behavior, physical exercise, resilience, and ego depletion. A six-year follow-up study by Kraplin et al.¹⁷ investigated the long-term and reciprocal relationship between value-based decision-making and addictive behavior in a community sample of young adults, and found a temporal stability in both decision-making and addictive behavior across the follow-ups, but there was only limited evidence for predictive cross-lagged relationships, highlighting the importance of multifaceted approaches to understand addiction. Finally, a preclinical study by McNamara et al.¹⁸ examined the concept of frontloading, a behavior pattern where a greater intensity of substance use occurs at the start of the substance exposure period, as well as approach-avoidance conflict behavior, during alcohol-seeking while administering mild footshock in rats. Findings revealed key sex differences and the relevance of both frontloading patterns and conflict preference in predicting future addiction-like phenotypes in a preclinical model.

In sum, each article has significantly contributed to the scientific understanding of addiction, with potential implications for clinical applications. We are hopeful that the findings from this article collection and the broader efforts of the scientific and clinical community worldwide will eventually lead to the further development of better tools and methods to prevent, diagnose, and treat SUD and behavioral addictions.

Author contributions

C.K. and M.M. wrote, reviewed, and edited the main manuscript text.

Competing interests

The authors declare no competing interests.