An exploration of addiction in adults experiencing early-life stress: a metasynthesis

An Umbrella Review of the Links Between Adverse Childhood Experiences and Substance Misuse: What, Why, and Where Do We Go from Here?

BACKGROUND AND OBJECTIVES

A wealth of research has identified adverse childhood experiences (ACEs; abuse, neglect, violence or disorder in the home) as a strong risk factor for substance misuse. Synthesis of the existing evidence is critical to shape policy and inform directions for future research. Existing reviews have focused on specific substances or substance use outcomes (eg, disorder), and do not include discussion of the mechanisms that operate between ACEs and substance misuse. The current umbrella review aims to synthesize reviews on the relationship between ACEs and substance misuse, review the evidence on the mechanisms linking these, identify existing gaps in our knowledge, and discuss critical directions for future research, practice, and public policy.

METHODS

Two electronic databases (PsycINFO and Medline) were searched for reviews published between 1998 and 2022 on the link between ACEs and substance misuse. Twenty articles met eligibility criteria and were qualitatively synthesized.

RESULTS

Results overwhelmingly demonstrated an elevated risk of substance misuse or disorder, among adolescents and adults exposed to ACEs. Research on the mechanisms that explain this link highlights a multitude of potential intervention targets, with childhood stress propelling a cascade of effects across neurobiological, endocrine, immune, metabolic, and nervous systems, impacting psychosocial and cognitive functioning. Nonetheless, the literature is subject to limitations surrounding potential unmeasured cofounders and causality, as well as decontextualizing childhood adversity from broader structural issues that influence the link between ACEs and substance misuse. Research, policy, and practice that seek to holistically understand and address the relationship between ACEs and substance misuse within the broader social determinants of health is crucial.

The Effects of Rosiglitazone on Task Specific Anxiety-Like Behavior and Novelty Seeking in a Model of Chronic Adolescent Unpredictable Stress

Adolescence is characterized as a period of increased social behavior, risk taking, and novelty seeking, partly due to ongoing maturation in critical brain areas and the hypothalamic-pituitary-adrenal (HPA) negative-feedback system. During this period there is heightened vulnerability to stress that can drive neuro-immune-endocrine remodeling, resulting in the emergence of maladaptive behaviors that increase susceptibility to alcohol and substance abuse. Here we used a rat model to investigate the impact of chronic adolescent unpredictable stress on a battery of behavioral measures to assess anxiety, novelty seeking, risk taking, depression, and voluntary ethanol consumption while determining whether the PPARγ agonist rosiglitazone can attenuate these effects. Adolescent female rats that experienced stress showed increased risk taking behavior and novelty seeking behavior with no change in ethanol consumption. The administration of rosiglitazone during stress induction attenuated stress-induced cortisol elevation, normalized risk taking behavior in a model anxiety, and attenuated novelty seeking in a task-specific manner. Depressive-like behavior was not impacted by adolescent unpredictable stress or the administration of rosiglitazone. The results from this study demonstrate that exposure to unpredictable stress during adolescence increases the prevalence of maladaptive behaviors that are known to increase susceptibility to alcohol and substance abuse, and that rosiglitazone may be an effective therapeutic to attenuate the emergence of select risk taking and novelty seeking behaviors in females.

Epigenetics of childhood trauma: Long term sequelae and potential for treatment

Childhood trauma (CT) can have persistent effects on the brain and is one of the major risk factors for neuropsychiatric diseases in adulthood. Recent advances in the field of epigenetics suggest that epigenetic factors such as DNA methylation and histone modifications, as well as regulatory processes involving non-coding RNA are associated with the long-term sequelae of CT. This narrative review summarizes current knowledge on the epigenetic basis of CT and describes studies in animal models and human subjects examining how the epigenome and transcriptome are modified by CT in the brain. It discusses psychological and pharmacological interventions that can counteract epigenetic changes induced by CT and the need to establish longitudinal assessment after CT for developing more effective diagnostics and treatment strategies based on epigenetic targets.

The mediating role of tolerance for psychological pain in the relationship of childhood trauma to suicidal ideation in individuals with a substance use disorder

OBJECTIVES

The association between childhood trauma and suicidal ideation has been well documented in several populations, including individuals with a substance use disorder (SUD). However, a gap still exists in the literature regarding the mechanisms by which childhood trauma later impacts suicide risk. This cross-sectional study tested the effect of childhood trauma on suicidal ideation, as well as the mediating effect of tolerance for psychological pain (managing the pain and enduring the pain) in that relationship, controlling for the effect of depressive symptoms, in individuals with a SUD.

METHODS

A sample of 102 adults with a SUD participated in the study. Path analysis by structural equation␣modelling tested a mediation model.

RESULTS

Depressive symptoms and lower levels of managing the pain were found to fully mediate the association between childhood trauma and suicidal ideation.

CONCLUSIONS

Our results suggest that depressive symptoms and a lack of ability to manage psychological pain contribute towards explaining why traumatic childhood experiences may result in suicidal cognitions in individuals with SUDs. Moreover, they have relevant implications for prevention and clinical interventions regarding suicidal ideation in this population.

PRACTITIONER POINTS

Childhood trauma relates to suicidal ideation in individuals with a substance use disorder. Depressive symptoms contribute towards explaining why traumatic childhood experiences may result in suicidal cognitions. A lack of ability to manage psychological pain also contributes towards explaining this relationship. The obtained results have relevant implications for the prevention of and clinical intervention for suicidal ideation in SUD individuals.

Early childhood trauma, substance use and complex concurrent disorders among adolescents

PURPOSE OF REVIEW

To highlight the interdependence between early childhood trauma, substance use and complex concurrent disorders among adolescents and discuss the delayed response and gaps in the healthcare system.

RECENT FINDINGS

High-risk behavior such as suicidality, self-harm and hazardous substance use including overdose and the use of psychotropic substances for self-medication of mental health challenges is a growing concern. These symptoms are often related to early childhood trauma, substance use and complex concurrent disorders. Most countries do not have a youth mental healthcare system, there are no specific guidelines and only few programs addressing high-risk substance use are in place.

SUMMARY

In addition to the significance of traumatic experience for high-risk substance use and addiction, most parts of the system of care ignore the trauma aspect in treatment of substance use and focus on abstinence. There are hardly any early intervention programs, broader prevention strategies or evidence-based or target-group-oriented treatment offers.

Early Life Stress and Risks for Opioid Misuse: Review of Data Supporting Neurobiological Underpinnings

A robust body of research has shown that traumatic experiences occurring during critical developmental periods of childhood when neuronal plasticity is high increase risks for a spectrum of physical and mental health problems in adulthood, including substance use disorders. However, until recently, relatively few studies had specifically examined the relationships between early life stress (ELS) and opioid use disorder (OUD). Associations with opioid use initiation, injection drug use, overdose, and poor treatment outcome have now been demonstrated. In rodents, ELS has also been shown to increase the euphoric and decrease antinociceptive effects of opioids, but little is known about these processes in humans or about the neurobiological mechanisms that may underlie these relationships. This review aims to establish a theoretical model that highlights the mechanisms by which ELS may alter opioid sensitivity, thereby contributing to future risks for OUD. Alterations induced by ELS in mesocorticolimbic brain circuits, and endogenous opioid and dopamine neurotransmitter systems are described. The limited but provocative evidence linking these alterations with opioid sensitivity and risks for OUD is presented. Overall, the findings suggest that better understanding of these mechanisms holds promise for reducing vulnerability, improving prevention strategies, and prescribing guidelines for high-risk individuals.

Mapping sign-tracking and goal-tracking onto human behaviors

As evidenced through classic Pavlovian learning mechanisms, environmental cues can become incentivized and influence behavior. These stimulus-outcome associations are relevant in everyday life but may be particularly important for the development of impulse control disorders including addiction. Rodent studies have elucidated specific learning profiles termed 'sign-tracking' and 'goal-tracking' which map onto individual differences in impulsivity and other behaviors associated with impulse control disorders' etiology, course, and relapse. Whereas goal-trackers are biased toward the outcome, sign-trackers fixate on features that are associated with but not necessary for achieving an outcome; a pattern of behavior that often leads to escalation of reward-seeking that can be maladaptive. The vast majority of the sign- and goal-tracking research has been conducted using rodent models and very few have bridged this concept into the domain of human behavior. In this review, we discuss the attributes of sign- and goal-tracking profiles, how these are manifested neurobiologically, and how these distinct learning styles could be an important tool for clinical interventions in human addiction.

COVID-19 Related Distress Is Associated With Alcohol Problems, Social Media and Food Addiction Symptoms: Insights From the Italian Experience During the Lockdown

Background: Several scholars hypothesize that one of the most negative impacts of the coronavirus disease 2019 (COVID-19) crisis would concern the increase of prevalence and severity of both substances and behavioral addiction. Despite the general concerns about the increase of prevalence and severity of addictions related to the COVID-19 emergency, few data are still available. Thus, the main aim of this study was to investigate the association between COVID-19 related distress and: (i) alcohol problems, (ii) social media addiction (SMA) symptoms, (iii) food addiction (FA) symptoms. Methods: A national online-survey was carried out during the Italian lockdown (i.e., 9 March 2020-4 May 2020). In the current study, 1,519 participants (365 men and 1,154 women, mean age: 28.49 ± 10.89 years) were included. The survey included socio-demographic related items (e.g., age, sex, residential regions, education level, civil status, tobacco use, etc.), as well as ad-hoc developed questions aimed to investigate COVID-19 related variables (e.g., isolation/quarantine, personal diagnosis to COVID-19, friends or relatives with COVID-19 diagnosis, etc.). Participants also completed the following self-report measures in order to investigate: the psychological impact of COVID-19, alcohol problems, SMA symptoms, FA symptoms, and impulsivity. Results: The psychological impact of COVID-19 was independently associated with alcohol problems (β = 0.058, p = 0.043), SMA symptoms (β = 0.259, p < 0.001), and FA symptoms (β = 0.150, p < 0.001). Conclusion: Taken together, our results seem to confirm the general concerns about the negative impacts of the COVID-19 emergency on addictive behaviors, suggesting that this issue should be carefully monitored.

Negative consequences of early-life adversity on substance use as mediated by corticotropin-releasing factor modulation of serotonin activity

Early-life adversity is associated with increased risk for substance abuse in later life, with women more likely to report past and current stress as a mediating factor in their substance use and relapse as compared to men. Preclinical models of neonatal and peri-adolescent (early through late adolescence) stress all support a direct relationship between experiences of early-life adversity and adult substance-related behaviors, and provide valuable information regarding the underlying neurobiology. This review will provide an overview of these animal models and how these paradigms alter drug and alcohol consumption and/or seeking in male and female adults. An introduction to the corticotropin-releasing factor (CRF) and serotonin systems, their development and their interactions at the level of the dorsal raphe will be provided, illustrating how this particular stress system is sexually dimorphic, and is well positioned to be affected by stressors early in development and throughout maturation. A model for CRF-serotonin interactions in the dorsal raphe and how these influence dopaminergic activity within the nucleus accumbens and subsequent reward-associated behaviors will be provided, and alterations to the activity of this system following early-life adversity will be identified. Overall, converging findings suggest that early-life adversity has long-term effects on the functioning of the CRF-serotonin system, highlighting a potentially important and targetable mediator linking stress to addiction. Future work should focus on identifying the exact mechanisms that promote long-term changes to the expression and activity of CRF receptors in the dorsal raphe. Moreover, it is important to clarify whether similar neurobiological mechanisms exist for males and females, given the sexual dimorphism both in CRF receptors and serotonin indices in the dorsal raphe and in the behavioral outcomes of early-life adversity.

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Early life stress increases risk for substance abuse in adulthood.

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Stress and drugs increase CRF which alters serotonin release in the brain.

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CRF₂ receptor expression in the dorsal raphe is altered by early life stress.

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Resultant changes to serotonin output facilitates dopamine in the accumbens.

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CRF₂-sertotonin-dopamine interactions may link early life stress with substance abuse.