Stress, sensitive periods, and substance abuse

Intersection of adverse childhood experiences, suicide and overdose prevention

Adverse childhood experiences (ACEs), suicide and overdose are linked across the life course and across generations and share common individual-, interpersonal-, community- and societal-level risk factors. The purpose of this review is to summarise the shared aetiology of these public health issues, synthesise evidence regarding potential community- and societal-level prevention strategies and discuss future research and practice directions.Growing evidence shows the potential for community- and societal-level programmes and policies, including higher minimum wage; expanded Medicaid eligibility; increased earned income tax credits, child tax credits and temporary assistance for needy families benefits; Paid Family Leave; greater availability of affordable housing and rental assistance; and increased participation in the Supplemental Nutrition Assistance Program (SNAP), to contribute to ACEs, suicide and overdose prevention. Considerations for future prevention efforts include (1) expanding the evidence base through rigorous research and evaluation; (2) assessing the implications of prevention strategies for equity; (3) incorporating a relational health perspective; (4) enhancing community capacity to implement, scale and sustain evidenced-informed prevention strategies; and (5) acknowledging that community- and societal-level prevention strategies are longer-term strategies.

Sex differences in the roles of nicotine use and puberty on youth C-reactive protein levels: Effects above and beyond adversity

Inflammation likely mediates associations between nicotine use and negative health outcomes. Sex differences have been observed in nicotine use-inflammation links, and physiological processes during puberty might allow for these differences to arise. In this cross-sectional study of 498 youth (ages 8-13, 52% girls, 77% with history of child maltreatment (CM) investigation), sex-differentiated associations between self-reported nicotine use and high-sensitivity C-reactive protein (hs-CRP) were explored. Additionally, self-reported pubertal stage was investigated as a moderator of such nicotine use-hs-CRP links. Hierarchical generalized estimating equation models were adjusted for a wide range of adversity effects: CM investigation history derived from state records, self- and caregiver-report of traumatic life events, adversity-related demographic risk factors (i.e., identification with historically marginalized racial and ethnic groups, household income), and other characteristics that may influence the variables of interest (e.g., medication use, age, body mass index). Nicotine use had a negative main effect on hs-CRP among boys (β = -0.50, p = 0.02), and pubertal stage did not moderate this association (β = 0.06, p = 0.71). In contrast, pubertal stage moderated the association between nicotine use and hs-CRP among girls (β = 0.48, p = 0.02) such that a positive association between nicotine use and hs-CRP levels was stronger at more advanced pubertal stages (β = 0.45, SE = 0.21, 95% CI [0.03, 0.87]). Findings suggest that puberty may influence the effect of nicotine on inflammation in sex-differentiated ways and have implications for timing of prevention and treatment efforts geared toward reducing nicotine use and subsequent inflammation-related health risk among youth.

Affective-Sexual Behaviors in Youth: Analysis of a Public Health Survey in the School Setting

INTRODUCTION

Adolescence is a critical period for the development of affectivity and sexuality. Adolescents begin to explore their sexual identities, form intimate relationships, and learn to manage their emotions in new and complex contexts. This study aims to analyze the prevalence of habits and behaviors related to the affective-sexual health of adolescents in the fourth year of ESO, identifying risk factors, comparing their behaviors and risks, monitoring these behaviors, analyzing their pornography consumption, and evaluating the use of the internet as a source of sexual information.

METHOD

Descriptive cross-sectional study using questionnaires. Participants are fourth-year ESO students from a school in the Baix Llobregat province (Catalonia), aged between 14 and 18 years. Descriptive and bivariate statistical analyses are conducted using the chi-square test and p-value calculations with the R Project software. Frequency and percentage analyses are also used to describe the health behaviors of the participants.

RESULTS

The study reveals that girls have better knowledge of the contraceptive pill and male condom than boys. Sexual initiation and condom use management vary between the genders, with girls being more capable of persuading their partners to use them. Pornography consumption also shows significant differences in terms of the age of initiation and frequency between boys and girls.

CONCLUSIONS

This study on adolescent affectivity and sexuality reveals knowledge about contraceptives, early sexual initiation, and high pornography consumption, highlighting the need for early and diverse affective-sexual education, youth empowerment, and media misinformation management to promote safer and healthier behaviors within municipal public health.

Prevention and Management of Risky Behaviors in Adolescents, Focusing on Suicide, Substance Use, and Risky Sexual Behaviors through Empowerment Programs: A Narrative Review

Background

Empowering adolescents to manage and reduce unhealthy behaviors and promote adaptive behaviors is a promising approach to promoting healthy behaviors. This review was an attempt to evaluate adolescent empowerment programs aimed at preventing and managing risky behaviors.

Materials and Methods

This narrative review was conducted in 2023. The texts were reviewed in two sections: (1) a review of articles and books in databases and (2) a review of international websites. The keywords used to search for studies and programs included substance-related disorders, risky behaviors, empowerment, program, adolescent, suicide, and risky sexual behaviors. These keywords were individually searched in international databases such as "PubMed, Scopus, and Web of Science." In the second section, a search was conducted on the websites of international organizations such as the World Health Organization (WHO). The inclusion criteria included having the full text of the original articles, articles in English, articles related to the development and evaluation of the effectiveness of empowerment programs, and the age range of adolescents. The texts that only had abstracts and were in non-English languages were excluded.

Results

The programs designed to empower adolescents were in three areas: (1) community-based and peer-based programs, (2) family-based programs, and (3) comprehensive programs. Most programs focused on peer group participation and skill interventions.

Conclusions

A powerful and effective empowering program for adolescents to prevent and control risky behaviors should be designed in the form of comprehensive programs in social, educational, economic, and health dimensions, and with the active engagement and participation of adolescents.

Could school programs based on social-emotional learning prevent substance abuse among adolescents?

In this editorial, we comment on the article Adolescent suicide risk factors and the integration of social-emotional skills in school-based prevention programs by Liu et al. While the article focused on the issue of suicide and social-emotional learning programs as a possible intervention, we here discuss evidence of other reported outcomes and if it could be an effective way to prevent substance abuse among adolescents.

Individual and Community level Developmental Adversities: Associations with Marijuana and Alcohol Use in Late-Adolescents and Young Adults

Exposure to community and individual level stressors during adolescence has been reported to be associated with increased substance use. However, it remains unclear what the relative contribution of different community- and individual-level factors play when alcohol and marijuana use become more prevalent during late adolescence. The present study uses a large longitudinal sample of adolescents (Wave 1: N = 2017; 55% Female; 54.5% White, 22.3% Black, 8% Hispanic, 15% other) to evaluate the association and potential interactions between community- and individual-level factors and substance use from adolescence to young adulthood (Wave 1 to Wave 3 Age Mean [SD]: 16.7 [1.1], 18.3 [1.2], 19.3 [1.2]). Across three waves of data, multilevel modeling (MLM) is used to evaluate the association between community affluence and disadvantage, individual household socioeconomic status (SES, measured as parental level of education and self-reported public assistance) and self-reported childhood maltreatment with self-reported 12-month alcohol and 12-month marijuana use occasions. Sample-selection weights and attrition-adjusted weights are accounted for in the models to evaluate the robustness of the estimated effects. Across the MLMs, there is a significant positive association between community affluence and parental education with self-reported alcohol use but not self-reported marijuana use. In post hoc analyses, higher neighborhood affluence in older adolescents is associated with higher alcohol use and lower use in younger adolescents; the opposite association is found for neighborhood disadvantage. Consistent with past literature, there is a significant positive association between self-reported childhood maltreatment and self-reported 12-month alcohol and 12-month marijuana use. Results are largely consistent across weighted and unweighted analyses, however, in weighted analyses there is a significant negative association between community disadvantage and self-reported 12-month alcohol use. This study demonstrates a nuanced relationship between community- and individual-level factors and substance use during the transitional window of adolescence which should be considered when contextualizing and interpreting normative substance use during adolescence.

Childhood adversity and psychopathology: the dimensions of timing, type and chronicity in a population-based sample of high-risk adolescents

BACKGROUND

Research on childhood adversity and psychopathology has begun investigating the dimension of timing, however the results have been contradictory depending on the study population, outcome and how adverse life events (ALEs) were operationalized. Additionally, studies so far typically focus only on a narrow range of psychiatric diagnoses or symptoms. The current cross-sectional study aimed to examine the association between timing, type and chronicity of ALEs and adolescent mental health problems.

METHODS

Adolescents from a population-based cohort oversampled on emotional and behavioral problems (mean age 14.8; range 12-17, N = 861) were included in the current analysis. Primary caregivers were interviewed on what ALEs adolescents experienced. ALEs were defined in two ways: (1) broad operationalization, including school difficulties, parental divorce, and family sickness; and (2) physically threatening abuse only, including physical and sexual violence. After looking at lifetime ALEs, we turned to chronicity, timing and sex differences. We focused on overall psychiatric symptoms as well as specific domains of emotional and behavioral problems, assessed using the Youth Self Report (YSR) and psychotic experiences assessed using the Prodromal Questionnaire-16 (PQ-16). A series of linear models adjusted for sociodemographic and parental factors were used.

RESULTS

Lifetime ALEs were associated with all types of psychopathology, with relatively bigger effect sizes for broad than for physical ALEs. The latter associations were found to be more robust to unmeasured confounding. The 9-12 age period of experiencing both broad and physical ALE's was most saliently associated with any psychopathology. Girls were more at risk after experiencing any ALEs, especially if the adversity was chronic or ALEs took place after the age of 12.

CONCLUSIONS

Broad as well as physical ALEs are associated with psychopathology, especially ALEs experienced during the 9-12 age period. Physical ALEs may be more useful in investigating specific etiological factors than broad ALEs. Sex differences may not emerge in lifetime measures of ALEs, but can be important for chronic and later childhood adversity.

Male and female variability in response to chronic stress and morphine in C57BL/6J, DBA/2J, and their BXD progeny

Drug addiction is a multifactorial syndrome in which genetic predispositions and exposure to environmental stressors constitute major risk factors for the early onset, escalation, and relapse of addictive behaviors. While it is well known that stress plays a key role in drug addiction, the genetic factors that make certain individuals particularly sensitive to stress and thereby more vulnerable to becoming addicted are unknown. In an effort to test a complex set of gene x environment interactions-specifically gene x chronic stress -here we leveraged a systems genetics resource: BXD recombinant inbred mice (BXD5, BXD8, BXD14, BXD22, BXD29, and BXD32) and their parental mouse lines, C57BL/6J and DBA/2J. Utilizing the chronic social defeat stress (CSDS) and chronic variable stress (CVS) paradigms, we first showed sexual dimorphism in the behavioral stress response between the mouse strains. Further, we observed an interaction between genetic background and vulnerability to prolonged exposure to non-social stressors. Finally, we found that DBA/2J and C57BL/6J mice pre-exposed to stress displayed differences in morphine sensitivity. Our results support the hypothesis that genetic variation in predisposition to stress responses influences morphine sensitivity and is likely to modulate the development of drug addiction.

Perceived racism and discrimination and youth substance use in the United States - Intersections with sex and ethnicity

OBJECTIVES

This study sought to examine associations between U.S. adolescents' perceived racism and discrimination (PRD) at school and current substance use.

METHODS

Data were drawn from the Adolescent Behaviors and Experiences Survey (ABES), a probability sample of U.S. high school students in 2021 (n = 7705). Multivariable regression models were conducted to examine associations of PRD with current (past 30-day) use of tobacco products, marijuana, alcohol, and prescription opioid misuse. Interaction effects of PRD and demographic factors were tested.

RESULTS

Among participants in the 2021 ABES, PRD was associated with higher odds of current use of tobacco (AOR = 1.3, p = 0.03), marijuana (AOR = 1.3, p = 0.03), alcohol (AOR = 1.2, p = 0.03), and misuse of prescription opioids (AOR = 1.6, p = 0.004). The effects of PRD on current tobacco and alcohol use differed by Hispanic and non-Hispanic adolescents (interaction effect = 0.007 and 0.01, respectively) with higher odds among Hispanic youth than among non-Hispanic counterparts. The associations of PRD and current tobacco use, marijuana use, alcohol use, and misuse of prescription opioids were moderated by sex with more pronounced effects on males than females.

CONCLUSIONS

Efforts to promote awareness and create support environments that value diversity and inclusivity at school are needed to mitigate adolescent exposure to racism and discrimination.

COVID-19 and Caregiver Risk Factors for Child Maltreatment: The Pandemic in Review

The COVID-19 pandemic has fostered an environment for increased risk of child maltreatment (CM) as families experience increased psychosocial and financial burdens and spend unprecedented amounts of time together in the home. This narrative review aimed to summarize empirical findings on existing or new pandemic-related risk factors among caregivers. A combination of search terms related to CM and COVID-19 were used to identify articles published within five databases between February 2020 and July 2022. Literature searches produced 113 articles, of which 26 published across 12 countries met inclusion criteria. Four previously well-established risk factors for CM perpetration continued to persist during the pandemic, including stress, parental mental health, financial concerns, and parental substance use. Of note, inconsistent definitions and measures were used to capture these risk factors. Several additional emerging and understudied risk factors were also identified among limited articles, such as food insecurity and parental education. Findings emphasize the ongoing need for evidence-based interventions to address CM risk during the pandemic, including parent training programs. However, consolidated measures and consistent conceptualization of risk factors are needed to advance the study of CM. Going forward, practitioners and researchers should (a) strengthen the identification process for families at greatest risk for CM, and particularly those vulnerable to pandemic-related stressors; and (b) augment delivery of CM prevention strategies and evidence-based programs to fit the pandemic context.

Translating Developmental Neuroscience to Understand Risk for Psychiatric Disorders

The transition from childhood to adulthood represents the developmental time frame in which the majority of psychiatric disorders emerge. Recent efforts to identify risk factors mediating the susceptibility to psychopathology have led to a heightened focus on both typical and atypical trajectories of neural circuit maturation. Mounting evidence has highlighted the immense neural plasticity apparent in the developing brain. Although in many cases adaptive, the capacity for neural circuit alteration also induces a state of vulnerability to environmental perturbations, such that early-life experiences have long-lasting implications for cognitive and emotional functioning in adulthood. The authors outline preclinical and neuroimaging studies of normative human brain circuit development, as well as parallel efforts covered in this issue of the Journal, to identify brain circuit alterations in psychiatric disorders that frequently emerge in developing populations. Continued translational research into the interactive effects of neurobiological development and external factors will be crucial for identifying early-life risk factors that may contribute to the emergence of psychiatric illness and provide the key to optimizing treatments.

Timing and type of adverse life events: Impact on substance use among high-risk adolescents

A robust association has been reported between childhood adverse life events (ALEs) and risky substance use in adolescence. It remains unclear, however, what the impact of type and timing of these ALEs is. We investigated the association between ALEs and substance use in adolescents. ALEs were operationalized as broad (e.g., moving, parental divorce, family sickness) or physically threatening (physical and/or sexual abuse). First, we examined lifetime ALEs, followed by an investigation into their timing. The sample consisted of 909 adolescents (aged 12-18 years) from a cohort oversampled on high levels of emotional and behavioral problems. The primary caregiver indicated which ALEs each adolescent experienced across their lifetime. Adolescents self-reported on number and frequency of substances used. Poisson and ordinal regression models were used to model the associations. The associations between lifetime ALEs and a substance used were observed only for physical ALEs (incidence rate ratio 1.18 [1.03, 1.35], p = 0.02). When investigating timing, physical ALEs after the age of 12 predicted number of substances used (IRR 1.36 [1.13, 1.63], p < .001). Recent ALEs (occurring after age 12) seem to have considerable impact on substance use. Alcohol and drugs as a coping mechanism were considered a plausible explanation for the results.

Climate Change and Substance-Use Behaviors: A Risk-Pathways Framework

Climate change is undermining the mental and physical health of global populations, but the question of how it is affecting substance-use behaviors has not been systematically examined. In this narrative synthesis, we find that climate change could increase harmful substance use worldwide through at least five pathways: psychosocial stress arising from the destabilization of social, environmental, economic, and geopolitical support systems; increased rates of mental disorders; increased physical-health burden; incremental harmful changes to established behavior patterns; and worry about the dangers of unchecked climate change. These pathways could operate independently, additively, interactively, and cumulatively to increase substance-use vulnerability. Young people face disproportionate risks because of their high vulnerability to mental-health problems and substance-use disorders and greater number of life years ahead in which to be exposed to current and worsening climate change. We suggest that systems thinking and developmental life-course approaches provide practical frameworks for conceptualizing this relationship. Further conceptual, methodological, and empirical work is urgently needed to evaluate the nature and scope of this burden so that effective adaptive and preventive action can be taken.

Relapse risk revealed by degree centrality and cluster analysis in heroin addicts undergoing methadone maintenance treatment

BACKGROUND

Based on hubs of neural circuits associated with addiction and their degree centrality (DC), this study aimed to construct the addiction-related brain networks for patients diagnosed with heroin dependence undertaking stable methadone maintenance treatment (MMT) and further prospectively identify the ones at high risk for relapse with cluster analysis.

METHODS

Sixty-two male MMT patients and 30 matched healthy controls (HC) underwent brain resting-state functional MRI data acquisition. The patients received 26-month follow-up for the monthly illegal-drug-use information. Ten addiction-related hubs were chosen to construct a user-defined network for the patients. Then the networks were discriminated with K-means-clustering-algorithm into different groups and followed by comparative analysis to the groups and HC. Regression analysis was used to investigate the brain regions significantly contributed to relapse.

RESULTS

Sixty MMT patients were classified into two groups according to their brain-network patterns calculated by the best clustering-number-K. The two groups had no difference in the demographic, psychological indicators and clinical information except relapse rate and total heroin consumption. The group with high-relapse had a wider range of DC changes in the cortical-striatal-thalamic circuit relative to HC and a reduced DC in the mesocorticolimbic circuit relative to the low-relapse group. DC activity in NAc, vACC, hippocampus and amygdala were closely related with relapse.

CONCLUSION

MMT patients can be identified and classified into two subgroups with significantly different relapse rates by defining distinct brain-network patterns even if we are blind to their relapse outcomes in advance. This may provide a new strategy to optimize MMT.

Overdose mortality rates for opioids or stimulants are higher in males than females, controlling for rates of drug misuse: State-level data

Importance

Drug overdoses from opioids like fentanyl and heroin and stimulant drugs such as methamphetamine and cocaine are a major cause of mortality in the United States, with potential sex differences across the lifespan.

Objective

To determine overdose mortality for specific drug categories across the lifespan of males and females, using a nationally representative state-level sample.

Design

State-level analyses of nationally representative epidemiological data on overdose mortality for specific drug categories, across 10-year age bins (age range: 15-74).

Setting

Population-based study of Multiple Cause of Death 2020-2021 data from the Centers of Disease Control and Prevention (CDC WONDER platform).

Participants

Decedents in the United States in 2020-2021.

Main outcome measures

The main outcome measure was sex-specific rates of overdose death (per 100,000) for: synthetic opioids excluding methadone (ICD-10 code: T40.4; predominantly fentanyl), heroin (T40.1), psychostimulants with potential for misuse, excluding cocaine (T43.6, predominantly methamphetamine; labeled "psychostimulants" hereafter), and cocaine (T40.5). Multiple regression analyses were used to control for ethnic-cultural background, household net worth, and sex-specific rate of misuse of the relevant substances (from the National Survey on Drug Use and Health, 2018-2019).

Results

For each of the drug categories assessed, males had greater overall overdose mortality than females, after controlling for rates of drug misuse. The mean male/female sex ratio of mortality rate for the separate drug categories was relatively stable across jurisdictions: synthetic opioids (2.5 [95%CI, 2.4-2.7]), heroin, (2.9 [95%CI, 2.7-3.1], psychostimulants (2.4 [95%CI, 2.3-2.5]), and cocaine (2.8 [95%CI, 2.6-2.9]). With data stratified in 10-year age bins, the sex difference generally survived adjustment for state-level ethnic-cultural and economic variables, and for sex-specific misuse of each drug type (especially for bins in the 25-64 age range). For synthetic opioids, the sex difference survived adjustment across the lifespan (i.e., 10-year age bins ranging from 15-74), including adolescence, adulthood and late adulthood.

Conclusions and Relevance

The robustly greater overdose mortality in males versus females for synthetic opioids (predominantly fentanyl), heroin, and stimulant drugs including methamphetamine and cocaine indicate that males who misuse these drugs are significantly more vulnerable to overdose deaths. These results call for research into diverse biological, behavioral, and social factors that underlie sex differences in human vulnerability to drug overdose.

Sex- and exposure age-dependent effects of adolescent stress on ventral tegmental area dopamine system and its afferent regulators

Adolescent stress is a risk factor for schizophrenia. Emerging evidence suggests that age-dependent sensitive windows for childhood trauma are associated more strongly with adult psychosis, but the neurobiological basis and potential sex differences are unknown.Using in vivo electrophysiology and immunohistology in rats, we systematically compared the effects of two age-defined adolescent stress paradigms, prepubertal (postnatal day [PD] 21-30; PreP-S) and postpubertal (PD41-50; PostP-S) foot-shock and restraint combined stress, on ventral tegmental area (VTA) dopaminergic activity, pyramidal neuron activity in the ventral hippocampus (vHipp) and the basolateral amygdala (BLA), corticoamygdalar functional inhibitory control, and vHipp and BLA parvalbumin interneuron (PVI) impairments. These endpoints were selected based on their well-documented roles in the pathophysiology of psychosis.Overall, we found distinct sex- and exposure age-dependent stress vulnerability. Specifically, while males were selectively vulnerable to PreP-S-induced adult VTA dopamine neuron and vHipp hyperactivities, females were selectively vulnerable to PostP-S. These male selective PreP-S effects were correlated with stress-induced aberrant persistent BLA hyperactivity, dysfunctional prefrontal inhibitory control of BLA neurons, and vHipp/BLA PVI impairments. In contrast, female PostP-S only produced vHipp PVI impairments in adults, with the BLA structure and functions largely unaffected.Our results indicated distinct adolescent-sensitive periods during which stress can sex-dependently confer maximal risks to corticolimbic systems to drive dopamine hyperactivity, which provide critical insights into the neurobiological basis for sex-biased stress-related psychopathologies emphasizing but not limited to schizophrenia. Furthermore, our work also provides a framework for future translational research on age-sensitive targeted interventions.

Cannabis in Adolescence: Lasting Cognitive Alterations and Underlying Mechanisms

Cannabis consumption during adolescence is an area of particular concern, owing to changes in the social and political perception of the drug, and presents a scientific, medical, and economic challenge. Major social and economic interests continue to push toward cannabis legalization as well as pharmaceutical development. As a result, shifting perceptions of both legal and illicit cannabis use across the population have changed the collective evaluation of the potential dangers of the product. The wave of cannabis legalization therefore comes with new responsibility to educate the public on potential risks and known dangers associated with both recreational and medical cannabis. Among these is the risk of long-term cognitive and psychological consequences, particularly following early-life initiation of use, compounded by high-potency and/or synthetic cannabis, and heavy/frequent use of the drug. Underlying these cognitive and psychiatric consequences are lasting aberrations in the development of synaptic function, often secondary to epigenetic changes. Additional factors such as genetic risk and environmental influences or nondrug toxic insults during development are also profound contributors to these long-term functional alterations following adolescent cannabis use. Preclinical studies indicate that exposure to cannabinoids during specific windows of vulnerability (e.g., adolescence) impacts neurodevelopmental processes and behavior by durably changing dendritic structure and synaptic functions, including those normally mediated by endogenous cannabinoids and neuronal circuits.

Association between mild traumatic brain injury, brain structure, and mental health outcomes in the Adolescent Brain Cognitive Development Study

BACKGROUND

Children that experience a mild traumatic brain injury (mTBI) are at an increased risk of neural alterations that can deteriorate mental health. We test the hypothesis that mTBI is associated with psychopathology and that structural brain metrics (e.g., volume, area) meaningfully mediate the relation in an adolescent population.

METHODS

We analyzed behavioral and brain MRI data from 11,876 children who participated in the Adolescent Brain Cognitive Development (ABCD) Study. Mixed-effects models were used to examine the longitudinal association between mTBI and mental health outcomes. Bayesian methods were used to investigate brain regions that are intermediate between mTBI and symptoms of poor mental health.

RESULTS

There were 199 children with mTBI and 527 with possible mTBI across the three ABCD Study visits. There was a 7% (IRR = 1.07, 95% CI: 1.01, 1.13) and 15% (IRR = 1.16, 95% CI: 1.05, 1.26) increased risk of emotional or behavioral problems in children that experienced possible mTBI or mTBI, respectively. Possible mTBI was associated with a 17% (IRR: 1.17, 95% CI: 0.99, 1.40) increased risk of experiencing distress following a psychotic-like experience. We did not find any brain regions that meaningfully mediated the relationship between mTBI and mental health outcomes. Analysis of volumetric measures found that approximately 2% to 5% of the total effect of mTBI on mental health outcomes operated through total cortical volume. Image intensity measure analyses determined that approximately 2% to 5% of the total effect was mediated through the left-hemisphere of the dorsolateral prefrontal cortex.

CONCLUSION

Results indicate an increased risk of emotional and behavioral problems in children that experienced possible mTBI or mTBI. Mediation analyses did not elucidate the mechanisms underlying the association between mTBI and mental health outcomes.

Adverse childhood experiences and adolescent drug use in the UK: The moderating role of socioeconomic position and ethnicity

Rationale

There is a paucity of prospective UK studies exploring the role of Adverse Childhood Experiences (ACEs) on adolescent teenage drug use and even less is known about the complex interplay between ACEs and adolescent social, demographic, and economic characteristics. To address these gaps, we use rich longitudinal data from the nationally representative Millennium Cohort Study.

Methods

Sex-stratified survey logistic regression modelling was applied using data from 9,476 adolescents and their parents to examine associations between ACEs between ages 3 and 14 years and drug use at ages 14 and 17 years. We a) explore the extent to which associations are robust to adjustment for ethnicity, family income, parental social class, and parental education, b) examine whether associations differ by these factors, and c) estimate the proportion of drug use at ages 14 and 17 years attributable to ACEs after controlling for these factors.

Results

Half of MCS cohort members had been exposed to at least one ACE and approximately 1 in 11 were exposed to 3+ ACEs. Multivariable analyses suggest that ACEs were associated with a higher likelihood of drug use at age 14 than age 17, especially for girls. No evidence was found that either advantaged socio-economic position or ethnicity acted as a buffer against the negative effects of ACEs in relation to adolescent drug use. Finally, we found that prevention of exposure to sexual violence, bullying and violence within the household (if causal) is more important for girls' drug use at age 14 than age 17.

Conclusions

ACEs are associated with adolescent drug use with potential consequences on wider aspects of young people's lives, regardless of their social, ethnic, or economic background, adding further urgency to the need to reduce the incidence of these negative experiences.

Vulnerability for alcohol use disorder after adverse childhood experiences (AUDACE): protocol for a longitudinal fMRI study assessing neuropsychobiological risk factors for relapse

BACKGROUND

Adverse childhood experiences (ACE) are common and may predispose affected individuals to various health problems, including alcohol use disorder (AUD). Although a relationship between ACE and AUD has been well-established, potential mechanisms that may underlie this relationship remain to be elucidated. The importance of these mechanisms with respect to relapse risk is of particular interest, given the clinical relevance of relapse in addictions. Thus, the aim of this study is to longitudinally assess the role of clinically relevant variables in the relationship between ACE and AUD, namely stress sensitivity, emotion processing, cue reactivity and cognitive functioning (response inhibition and working memory), in relation to relapse risk.

METHODS AND ANALYSIS

In this observational, longitudinal case-control study, 36 patients with AUD and heavy drinkers with varying degrees of ACE from a previous project (NCT03758053) as well as newly recruited participants from the same study population will be assessed. Besides measuring long-term relapse in AUD by re-examining these 36 previous participants after 2-2.5 years, factors contributing to short-term relapse will be examined by reassessing all participants on a 3-month follow-up. Furthermore, participants with no or mild ACE will be compared with participants with moderate to severe ACE to assess between-subject differences in risk factors for AUD. Questionnaires and interviews will thus be used to cover individuals' drinking behaviour and ACE. Emotion processing, stress sensitivity, cue reactivity and cognitive functioning will be assessed using task-based functional MRI (fMRI). Additionally, saliva cortisol and blood samples will be taken to measure hormonal stress response and to perform genome wide association analyses, respectively. The general linear model will be applied on the first level fMRI analyses, whereas for the second level analyses and analyses of behavioural data, t-tests, regression analyses, repeated-measures and one-way analysis of variances will be used.

ETHICS AND DISSEMINATION

This study has been approved by the ethics committee of the Medical Faculty Mannheim of Heidelberg University (ethics approval number: 2018-560N-MA with amendment from 29 June 2021). The findings of this study will be presented at conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05048758; Pre-results, clinicaltrials.gov.

Enduring disruption of reward and stress circuit activities by early-life adversity in male rats

In humans, early-life adversity (ELA) such as trauma, poverty, and chaotic environment is linked to increased risk of later-life emotional disorders including depression and substance abuse. These disorders involve underlying disruption of reward circuits and likely vary by sex. Accordingly, we previously found that ELA leads to anhedonia for natural rewards and cocaine in male rodents, whereas in females ELA instead increases vulnerability to addiction-like use of opioid drugs and palatable food. While these findings suggest that ELA-induced disruption of reward circuitry may differ between the sexes, the specific circuit nodes that are influenced by ELA in either sex remain poorly understood. Here, in adult male Sprague-Dawley rats, we ask how ELA impacts opioid addiction-relevant behaviors that we previously tested after ELA in females. We probe potential circuit mechanisms in males by assessing opioid-associated neuronal activation in stress and reward circuit nodes including nucleus accumbens (NAc), amygdala, medial prefrontal cortex (mPFC), and paraventricular thalamus. We find that ELA diminishes opioid-seeking behaviors in males, and alters heroin-induced activation of NAc, PFC, and amygdala, suggesting a potential circuit-based mechanism. These studies demonstrate that ELA leads to behavioral and neurobiological disruptions consistent with anhedonia in male rodents, unlike the increased opioid seeking we previously saw in females. Our findings, taken together with our prior work, suggest that men and women could face qualitatively different mental health consequences of ELA, which may be essential for individually tailoring future intervention strategies.

Stress, academic burnout, smartphone use types and problematic smartphone use: The moderation effects of resilience

Few studies have investigated stress in association with social and process smartphone use and how these types of use influence problematic smartphone use during the COVID-19 pandemic; furthermore, the moderation effects of resilience have been rarely tested in this model. For these, a cross-sectional survey was conducted involving 766 Chinese undergraduate students (74.4% female; M = 20.1 years, SD = 1.15) who were measured with their levels of stress, academic burnout, smartphone use types (social/process smartphone use), resilience, and problematic smartphone use. Based on the I-PACE theory, we built a structural equation model, and the results indicated that compared with social smartphone use, process smartphone use more related to problematic smartphone use; academic burnout fully mediated between stress and process smartphone use, and between stress and problematic smartphone use. Moreover, resilience moderated between stress and academic burnout, between academic burnout and process smartphone use, and between academic burnout and problematic smartphone use. We discuss the process smartphone use as a key indicator of problematic smartphone use and the role of academic burnout for linking stress and smartphone use behaviors. In addition, interventions for enhancing resilience should be launched in the future.

Neurodevelopmental origins of substance use disorders: Evidence from animal models of early-life adversity and addiction

Addiction is a chronic relapsing disorder with devastating personal, societal, and economic consequences. In humans, early-life adversity (ELA) such as trauma, neglect, and resource scarcity are linked with increased risk of later-life addiction, but the brain mechanisms underlying this link are still poorly understood. Here, we focus on data from rodent models of ELA and addiction, in which causal effects of ELA on later-life responses to drugs and the neurodevelopmental mechanisms by which ELA increases vulnerability to addiction can be determined. We first summarize evidence for a link between ELA and addiction in humans, then describe how ELA is commonly modeled in rodents. Since addiction is a heterogeneous disease with many individually varying behavioral aspects that may be impacted by ELA, we next discuss common rodent assays of addiction-like behaviors. We then summarize the specific addiction-relevant behavioral phenotypes caused by ELA in male and female rodents and discuss some of the underlying changes in brain reward and stress circuits that are likely responsible. By better understanding the behavioral and neural mechanisms by which ELA promotes addiction vulnerability, we hope to facilitate development of new approaches for preventing or treating addiction in those with a history of ELA.

Effects of early life stress during stress hyporesponsive period (SHRP) on anxiety and curiosity in adolescent rats

Repeated exposure to adverse experiences in early life, termed Early Life Stress (ELS), can increase anxiety disorders later in life. Anxiety is directly associated with curiosity, a form of intrinsic drive state associated with increased novelty-seeking behaviour and risk taking for challenging opportunities and could probably modulate learning and memory. In humans, elevated curiosity during adolescence tends to elicit increased exploration, novelty seeking, high risk-taking behaviour and heightened emotionality. Such behaviours are beneficial in maintaining social skills and cognitive functions later in life. We investigated whether ELS-induced anxiety impacts curiosity-like behaviour at adolescence in an animal model. ELS was induced by subjecting Sprague Dawley rat pups to maternal separation and isolation (MS) stress during the stress hyporesponsive period (SHRP) from post-natal days (PND) 4-PND 14. This rat model was tested for anxiety, spontaneous exploratory behaviour and curiosity-like behaviour in a custom-designed arena during adolescence (PND 30-45). ELS-induced changes in the stress were confirmed by corticosterone, while, basal dopamine level was estimated to understand the neurochemical basis of MS stress-induced changes in curiosity. We observed an increase in the levels of anxiety and intrinsic drive state such as curiosity-like behaviour, which was associated with elevated plasma corticosterone and dopamine in MS animals during adolescence suggesting the impact of ELS during SHRP on adolescent behaviour.

Prepulse inhibition can predict the motivational effects of cocaine in female mice exposed to maternal separation

The prepulse inhibition (PPI) of the startle response can identify the rodents that are more sensitive to the effects of cocaine. Mice with a lower PPI presented a higher vulnerability to the effects of cocaine and a higher susceptibility to developing a substance use disorder (SUD). Maternal separation with early weaning (MSEW) is a relevant animal model to induce motivational alterations throughout life. Nevertheless, only a few studies on females exist, even though they are more vulnerable to stress- and cocaine-related problems. Hence, the aim of the present study was to evaluate the ability of PPI to identify females with a greater vulnerability to the long-term consequences of early stress on the motivational effects of cocaine. Female mice underwent MSEW and were classified according to their high or low PPI. They were then assessed in the cocaine-induced locomotor sensitization test, the conditioned place preference paradigm or the operant self-administration paradigm. Additionally, they were also evaluated in the passive avoidance task, the tail-suspension and the splash tests. The results revealed that the females with lower PPI presented higher consequences of MSEW on the effects of cocaine and showed an increase in anhedonia-like behaviours. Our findings support that a PPI deficit could represent a biomarker of vulnerability to the effects of cocaine induced by MSEW.

Developmental Trajectories of Anhedonia in Preclinical Models

This chapter discusses how the complex concept of anhedonia can be operationalized and studied in preclinical models. It provides information about the development of anhedonia in the context of early-life adversity, and the power of preclinical models to tease out the diverse molecular, epigenetic, and network mechanisms that are responsible for anhedonia-like behaviors.Specifically, we first discuss the term anhedonia, reviewing the conceptual components underlying reward-related behaviors and distinguish anhedonia pertaining to deficits in motivational versus consummatory behaviors. We then describe the repertoire of experimental approaches employed to study anhedonia-like behaviors in preclinical models, and the progressive refinement over the past decade of both experimental instruments (e.g., chemogenetics, optogenetics) and conceptual constructs (salience, valence, conflict). We follow with an overview of the state of current knowledge of brain circuits, nodes, and projections that execute distinct aspects of hedonic-like behaviors, as well as neurotransmitters, modulators, and receptors involved in the generation of anhedonia-like behaviors. Finally, we discuss the special case of anhedonia that arises following early-life adversity as an eloquent example enabling the study of causality, mechanisms, and sex dependence of anhedonia.Together, this chapter highlights the power, potential, and limitations of using preclinical models to advance our understanding of the origin and mechanisms of anhedonia and to discover potential targets for its prevention and mitigation.

Sensitive Periods for Recovery from Early Brain Injury

The developing brain is remarkably plastic as it changes in response to a wide range of experiences including sensory and motor experience, psychoactive drugs, peer relationships, parent-infant interactions, gonadal hormones, intestinal flora, diet, and injury. There are sensitive periods for many of these experiences, including cerebral injury. Comparisons across mammalian species (humans, monkeys, cats, rats, mice) show a sensitive period for good outcomes from cerebral injury around the time of intense synaptogenesis. This period is postnatal in humans, cats, and rats, but prenatal in monkeys, reflecting the differences in neuronal development at birth across species. In addition, there appears to be a sensitive period prenatally during the time of maximum cortical neurogenesis and possibly during adolescence as well, although these periods are not as well studied as the period related to synaptogenesis and to date only examined in rats. Here we review the evidence for sensitive periods related to brain injury across species and propose mechanisms that may underlie the plasticity during these periods.

Associations of adverse childhood experiences with adolescent total sleep time, social jetlag, and insomnia symptoms

STUDY OBJECTIVE

Adverse childhood experiences (ACEs) are associated with sleep problems in adulthood, but less research has focused on ACEs and sleep during adolescence. The goal of the present study was to explore associations between ACEs reported at ages 5 and 9 years, and sleep (ie, total sleep time (TST), social jetlag, and insomnia symptoms) at age 15.

METHODS

Participants comprised 817 families from the Fragile Families and Child Wellbeing Study, a nationally representative sample of children born to unwed parents. Number of ACEs was constructed from primary-caregiver reports at ages 5 and 9, and sleep measures (ie, TST, social jetlag, and insomnia symptoms) were derived from adolescent-reported sleep behaviors at age 15.

RESULTS

Adjusting for sex and race/ethnicity, ACEs at age 9 were associated with longer weekend TST (B = 0.16, 95% CI = 0.04, 0.28), more social jetlag (B = 0.17, 95% CI = 0.07, 0.27), and higher odds of trouble falling asleep ≥3 times per week (Odds Ratio = 1.24, 95% CI = 1.01, 1.53). In females only, ACEs were associated with greater school night TST (B = 0.12, 95% CI = 0.01, 0.23). Results were similar after further adjustment for symptoms of anxiety and depression. Associations among ACEs, social jetlag, and insomnia symptoms appeared strongest among Non-Hispanic Black adolescents.

CONCLUSION

ACEs appear to be related to multiple aspects of sleep in adolescence. Additional research is needed to confirm these associations and examine the extent to which sleep disturbances associated with ACEs account for later health outcomes.

In vivo microdialysis shows differential effects of prenatal protein malnutrition and stress on norepinephrine, dopamine, and serotonin levels in rat orbital frontal cortex

Prenatal protein malnutrition (PPM) alters the developing brain including changes in monoaminergic systems and attention. In the present study, we used in vivo microdialysis to examine the relationship between PPM, acute stress, and extracellular serotonin (5HT), dopamine (DA) and norepinephrine (NE) in both hemispheres of lateral orbital frontal cortices (lOFC) in the adult rat. We hypothesized that prenatal protein malnutrition would alter extracellular concentrations of cortical monoamines. The effects of an acute restraint stress were also assessed because PPM alters the brain's response to stress. We used adult male, Long-Evans rats [10 prenatally malnourished (6% casein) and 10 prenatally well-nourished (25% casein)]. Samples were collected from the left and right hemispheres of the lOFC every 20 min for 6 hr total and quantified using high-performance liquid chromatography (HPLC). After 2 hr of sampling, animals were exposed to a 40-min restraint stress. Extracellular levels of NE were significantly higher in PPM animals than in well-nourished controls across both hemispheres at all time-points. In contrast, baseline levels of 5HT and DA levels did not differ between nutritional groups. 5HT levels, but not NE or DA levels, were elevated compared to baseline levels in both nutritional groups and in both hemispheres during the first 20 min of stress exposure. These data highlight the impact of PPM on neuromodulatory systems and the profile of changes in response to acute stress. Additional studies are needed to determine how these basal and stress-related responses impact cognitive performance and whether these differences persist during cognitive testing. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

NLRP3 Inflammasome Is Involved in Cocaine-Mediated Potentiation on Behavioral Changes in CX3CR1-Deficient Mice

Microglia, the primary immunocompetent cells of the brain, are suggested to play a role in the development of drug addiction. Previous studies have identified the microglia-derived pro-inflammatory factor IL1β can promote the progression of cocaine addiction. Additionally, the activation status of microglia and “two-hit hypothesis” have been proposed in the field of drug addiction to explain how early life stress (ELS) could significantly increase the incidence of drug addiction in later life. However, the mechanisms underlying microglia prime and full activation and their roles in drug addiction remain greatly unexplored. Here, we employed CX3CR1-GFP mice (CX3CR1 functional deficiency, CX3CR1−/−) to explore whether primed microglia could potentiate cocaine-mediated behavioral changes and the possible underlying mechanisms. CX3CR1−/− mice revealed higher hyperlocomotion activity and conditional place preference than wild-type (WT) mice did under cocaine administration. In parallel, CX3CR1−/− mice showed higher activity of NLR family pyrin domain-containing 3 (NLRP3) inflammasome than WT mice. Interestingly, CX3CR1 deficiency itself could prime NLRP3 signaling by increasing the expression of NLPR3 and affect lysosome biogenesis under basal conditions. Taken together, our findings demonstrated that the functional status of microglia could have an impact on cocaine-mediated reward effects, and NLRP3 inflammasome activity was associated with this phenomenon. This study was consistent with the two-hit hypothesis and provided solid evidence to support the involvement of microglia in drug addiction. Targeting the NLRP3 inflammasome may represent a novel therapeutic approach for ameliorating or blocking the development of drug addiction.

DNA methylation of the glucocorticoid receptor gene predicts substance use in adolescence: longitudinal data from over 1000 young individuals

Early life stress has been linked to increased methylation of the Nuclear Receptor Subfamily 3 Group C Member 1 (NR3C1) gene, which codes for the glucocorticoid receptor. Moreover, early life stress has been associated with substance use initiation at a younger age, a risk factor for developing substance use disorders. However, no studies to date have investigated whether NR3C1 methylation can predict substance use in young individuals. This study included adolescents 13-14 years of age that reported no history of substance use at baseline, (N = 1041; males = 46%). Participants contributed saliva DNA samples and were followed in middle adolescence as part of KUPOL, a prospective cohort study of 7th-grade students in Sweden. Outcome variables were self-reports of (i) recent use, (ii) lifetime use, and (iii) use duration of (a) alcohol, (b) tobacco products, (c) cannabis, or (d) any substance. Outcomes were measured annually for three consecutive years. The predictor variable was DNA methylation at the exon 1 F locus of NR3C1. Risk and rate ratios were calculated as measures of association, with or without adjustment for internalizing symptoms and parental psychiatric disorders. For a subset of individuals (N = 320), there were also morning and afternoon salivary cortisol measurements available that were analyzed in relation to NR3C1 methylation levels. Baseline NR3C1 hypermethylation associated with future self-reports of recent use and use duration of any substance, before and after adjustment for potential confounders. The overall estimates were attenuated when considering lifetime use. Sex-stratified analyses revealed the strongest association for cigarette use in males. Cortisol analyses revealed associations between NR3C1 methylation and morning cortisol levels. Findings from this study suggest that saliva NR3C1 hypermethylation can predict substance use in middle adolescence. Additional longitudinal studies are warranted to confirm these findings.

Methods and Challenges in Investigating Sex-Specific Consequences of Social Stressors in Adolescence in Rats: Is It the Stress or the Social or the Stage of Development?

Adolescence is a time of social learning and social restructuring that is accompanied by changes in both the hypothalamic-pituitary-gonadal axis and the hypothalamic-pituitary-adrenal (HPA) axis. The activation of these axes by puberty and stressors, respectively, shapes adolescent development. Models of social stress in rats are used to understand the consequences of perturbations of the social environment for ongoing brain development. This paper reviews the challenges in investigating the sex-specific consequences of social stressors, sex differences in the models of social stress used in rats and the sex-specific effects on behaviour and provides an overview of sex differences in HPA responding to stressors, the variability in pubertal development and in strains of rats that require consideration in conducting such research, and directions for future research.

The roles of child maltreatment and fathers in the development of substance use in an at-risk sample of youth: A longitudinal study

BACKGROUND

Despite ample cross-sectional evidence linking child maltreatment and father involvement to adolescent substance use, little is known about the longitudinal impact of child maltreatment and father involvement in the developmental course of substance use from early adolescence to late adolescence.

OBJECTIVE

The primary aim of the study was to examine the long-term effects of childhood maltreatment (i.e., maltreatment type, perpetrator identity) and the quality and quantity of father involvement on developmental trajectories of substance use among high-risk youth.

PARTICIPANTS AND SETTING

Data were drawn from the Longitudinal Studies of Child Abuse and Neglect. Study participants included 681 U.S. adolescents who had experienced or were at risk for child maltreatment.

METHODS

Latent Growth Poisson Modeling was conducted to examine developmental trajectories of substance use at ages 12, 14, 16, and 18.

RESULTS

Child emotional abuse and greater quantity of father involvement were associated with a higher initial number of substances used, while higher quality of father-child relationships was associated with a lower initial number of substances used. Emotional abuse and greater quantity of father involvement were associated with slower increases in the number of substances used over time.

CONCLUSIONS

The findings suggest that engaging fathers and promoting nurturing parenting and positive parent-adolescent interactions may be important for programs and policies aimed to prevent early adolescent substance use initiation. Furthermore, early identification of emotional abuse among adolescents could help to prevent initial polysubstance use onset.

The Developmental Origins of Opioid Use Disorder and Its Comorbidities

Opioid use disorder (OUD) rarely presents as a unitary psychiatric condition, and the comorbid symptoms likely depend upon the diverse risk factors and mechanisms by which OUD can arise. These factors are heterogeneous and include genetic predisposition, exposure to prescription opioids, and environmental risks. Crucially, one key environmental risk factor for OUD is early life adversity (ELA). OUD and other substance use disorders are widely considered to derive in part from abnormal reward circuit function, which is likely also implicated in comorbid mental illnesses such as depression, bipolar disorder, and schizophrenia. ELA may disrupt reward circuit development and function in a manner predisposing to these disorders. Here, we describe new findings addressing the effects of ELA on reward circuitry that lead to OUD and comorbid disorders, potentially via shared neural mechanisms. We discuss some of these OUD-related problems in both humans and animals. We also highlight the increasingly apparent, crucial contribution of biological sex in mediating the range of ELA-induced disruptions of reward circuitry which may confer risk for the development of OUD and comorbid neuropsychiatric disorders.

Early-life stress is associated with a preponderance of habitual responding in a novel instrumental avoidance learning paradigm

There is substantial evidence linking early-life stress (ELS) to negative health outcomes in adulthood, including addiction. However, the neurocognitive and behavioral mechanisms through which ELS increases these risks remain unclear. To address this gap in knowledge, we developed a novel instrumental learning paradigm to explore the effects of ELS on the balance of habitual versus goal-directed learning. Habits efficiently reproduce repetitive behaviors but are inflexible whenreward contingencies related to those behaviors change. Persisting in performing a response after its outcome has been devalued is the hallmark of habitual behavior in instrumental learning. Participants with a history of higher ELS were significantly more likely to make habitual responses in this instrumental avoidance learning paradigm than individuals with a history of lower ELS. Logistic regression analysis showed that ELS is significantly related to habitual responding over and above the effects of retrospective socioeconomic status, trait and state anxiety, depression and recent levels of stress. Analysis of the differential impacts of the type of ELS suggested that these effects are largely driven by experiences of physical neglect.

Early life stress-induced alterations in the activity and morphology of ventral tegmental area neurons in female rats

Childhood maltreatment, which can take the form of physical or psychological abuse, is experienced by more than a quarter of all children. Early life stress has substantial and long-term consequences, including an increased risk of drug abuse and psychiatric disorders in adolescence and adulthood, and this risk is higher in women than in men. The neuronal mechanisms underlying the influence of early life adversities on brain functioning remain poorly understood; therefore, in the current study, we used maternal separation (MS), a rodent model of early-life neglect, to verify its influence on the properties of neurons in the ventral tegmental area (VTA), a brain area critically involved in reward and motivation processing. Using whole-cell patch-clamp recordings in brain slices from adolescent female Sprague-Dawley rats, we found an MS-induced increase in the excitability of putative dopaminergic (DAergic) neurons selectively in the medial part of the VTA. We also showed an enhancement of excitatory synaptic transmission in VTA putative DAergic neurons. MS-induced alterations in electrophysiology were accompanied by an increase in the diameter of dendritic spine heads on lateral VTA DAergic neurons, although the overall dendritic spine density remained unchanged. Finally, we reported MS-related increases in basal plasma ACTH and corticosterone levels. These results show the long-term consequences of early life stress and indicate the possible neuronal mechanisms of behavioral disturbances in individuals who experience early life neglect.

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Adversity in early life is a predisposing factor for psychiatric disorders.

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Maternal separation (MS) increases excitability of dopaminergic VTA neurons.

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Early life stress enhances excitatory synaptic transmission in the VTA.

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MS changes morphology of dendritic spine heads on VTA dopaminergic neurons.

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Early life stress increases basal ACTH and corticosterone levels in adulthood.

Behavioral processes and risk for problem substance use in adolescents

This narrative review examines associations of delay discounting, response inhibition, sensation-seeking, and urgency with adolescent problem substance use. Each of these processes is linked to adult substance use disorders, is associated with conditions linked to increased risk for adolescent problem substance use, and predicts problem substance use. Notably, all processes are linked to early life adversity (ELA) exposure and most appear to help explain links between ELA exposure and problem substance use. These findings are consistent with a growing body of literature indicating ELA interferes with the development of neural circuits crucial to cognitive functioning and emotion regulation. Further, developmental trajectories of these processes generally align with maturational imbalance hypotheses of adolescent risk. Ongoing and pending large longitudinal studies may be essential for better understanding how ELA and other influences shapes these processes and the role of these processes in risk for problem substance use in adolescence and beyond. Finally it is possible that risk-related processes may be useful metrics in the context of implementing and evaluating strategies to prevent problem substance use in adolescence.

Cocaine-induced inheritable epigenetic marks may be altered by changing early postnatal fostering

Here, we explored the hypothesis that parental cocaine exposure could alter epigenetic machinery in their drug-naive offspring while early postnatal fostering may further modify the accompanied neurochemical and functional components. Variant drug-naive pups were produced from cocaine-exposed or unexposed C57BL/6 female mice that were matched with their male counterparts for mating. Within 3 days of birth, half of the pups were cross-fostered and nurtured by non-biological lactating dams. The pups were initially examined for locomotor activity and memory performance and subsequently for changes in DNA methylation in promoter regions of cAMP response element modulator (Crem) and Fosb in the prefrontal cortex at 48 days postnatum. The impact of postnatal fostering on these parameters was also investigated. Our results showed that cocaine exposure significantly decreased both Crem and Fosb methylation in the prefrontal cortex of progenitor mice, while similar patterns of methylation were replicated in the brains of drug-naive non-fostered offspring mice but reversed by postnatal fostering. Furthermore, offspring raised by cocaine-exposed dams were impaired in discriminative learning and exhibited memory decline, whereas locomotor activity remains unaltered in all groups of mice. Our data provide some evidence that indirect exposure to cocaine may cause marked epigenetic changes within the cortical networks of drug-naive descendants and that mediation by Crem/Fosb signalling in this brain region may be beneficial, while early postnatal fostering may further engineer molecular switching that may predispose the individual to future risky behaviours as well as accumulative potential to developing cognitive impairment later in life.

Stressful life events, the incidence of infertility, and the moderating effect of maternal responsiveness: a longitudinal study

Although the association between stress and poor reproductive health is well established, this association has not been examined from a life course perspective. Using data from the National Longitudinal Survey of Youth 1997 cohort (N = 1652), we fit logistic regression models to test the association between stressful life events (SLEs) (e.g., death of a close relative, victim of a violent crime) during childhood, adolescence, and early adulthood and later experiences of infertility (inability to achieve pregnancy after 12 months of intercourse without contraception) reported by female respondents. Because reactions to SLEs may be moderated by different family life experiences, we stratified responses by maternal responsiveness (based on the Conger and Elder Parent-Youth Relationship scale) in adolescence. After adjusting for demographic and environmental factors, in comparison to respondents with one or zero SLEs, those with 3 SLEs and ≥ 4 SLEs had 1.68 (1.16, 2.42) and 1.88 (1.38, 2.57) times higher odds of infertility, respectively. Respondents with low maternal responsiveness had higher odds of infertility that increased in a dose-response manner. Among respondents with high maternal responsiveness, only those experiencing four or more SLEs had an elevated risk of infertility (aOR = 1.53; 1.05, 2.25). In this novel investigation, we demonstrate a temporal association between the experience of SLEs and self-reported infertility. This association varies by maternal responsiveness in adolescence, highlighting the importance of maternal behavior toward children in mitigating harms associated with stress over the life course.

Reprogramming of the Immune System by Stress and Faulty Hormonal Imprinting

PURPOSE

Hormonal imprinting is taking place perinatally at the first encounter between the developing hormone receptors and their target hormones. However, in this crucial period when the developmental window for physiological imprinting is open, other molecules, such as synthetic hormones and endocrine disruptors can bind to the receptors, leading to faulty imprinting with life-long consequences, especially to the immune system. This review presents the factors of stress and faulty hormonal imprinting that lead to reprogramming of the immune system.

METHODS

Relevant publications from Pubmed since 1990 were reviewed and synthesized.

FINDINGS

The developing immune system is rather sensitive to hormonal effects. Faulty hormonal imprinting is able to reprogram the original developmental program present in a given cell, with lifelong consequences, manifested in alteration of hormone binding by receptors, susceptibility to certain (non-infectious) diseases, and triggering of other diseases. As stress mobilizes the hypothalamic-pituitary-adrenal axis if it occurred during gestation or perinatally, it could lead to faulty hormonal imprinting in the immune system, manifested later as allergic and autoimmune diseases or weakness of normal immune defenses. Hormonal imprinting is an epigenetic process and is carried to the offspring without alteration of DNA base sequences. This means that any form of early-life stress alone or in association with hormonal imprinting could be associated with the developmental origin of health and disease (DOHaD). As puberty is also a period of reprogramming, stress or faulty imprinting can change the original (developmental) program, also with life-long consequences.

IMPLICATIONS

Considering the continuous differentiation of immune cells (from blast-cells) during the whole life, there is a possibility of late-imprinting or stress-activated reprogramming in the immune system at any periods of life, with later pathogenetic consequences.

Xlr4 as a new candidate gene underlying vulnerability to cocaine effects

Although several studies have been performed in rodents, non-human primates and humans, the biological basis of vulnerability to develop cocaine addiction remains largely unknown. Exposure to critical early events (as Repeated Cross Fostering (RCF)) has been reported to increase sensitivity to cocaine effects in adult C57BL/6J female mice. Using a microarray approach, here we report data showing a strong engagement of X-linked lymphocyte-regulated 4a and 4b (Xlr4) genes in cocaine effects. The expression of Xlr4, a gene involved in chromatin remodeling and dendritic spine morphology, was reduced into the Nucleus Accumbens (NAc) of adult RCF C57BL/6J female. We used virally mediated accumbal Xlr4 down-modulation (AAVXlr4-KD) to investigate the role of this gene in vulnerability to cocaine effects. AAVXlr4-KD animals show a potentiated behavioral and neurochemical response to cocaine, reinstatement following cocaine withdrawal and cocaine-induced spine density alterations in the Medium-Sized Spiny Neurons of NAc. We propose Xlr4 as a new candidate gene mediating the cocaine effects.

Post-trauma anhedonia is associated with increased substance use in a recently-traumatized population

Recreational substance use (SU) can emerge or worsen in the aftermath of psychological trauma. Anhedonia is one reason for this problematic SU. Symptoms of posttraumatic stress disorder (PTSD) that represent anhedonia (post-trauma anhedonia; PTA) have been consistently linked to SU disorders. However, no prospective studies have examined whether changes in PTA over time are associated with problematic SU in recently-traumatized people, which was the goal of this study. 165 men and women were recruited as part of a prospective PTSD study in the emergency department of a Level 1 trauma center. Clinical assessments of PTSD and SU were administered at three and six months post-trauma. Compared to participants with minimal SU at six months post-trauma, high substance users at six months post-trauma showed significant increases in PTA during the three to six month time period. This relationship was significant even after accounting for variance associated with other factors, including PTSD symptoms such as re-experiencing and hyperarousal. Participants who demonstrated increases in SU during this time also showed significant increases in PTA, unlike those who demonstrated consistently minimal/no SU during this time. These findings indicate that PTA may be a mechanism through which SU problems emerge in recently-traumatized individuals.

Alcohol Use, Binge Drinking, and Drunkenness Experience in Adolescence: Complex Associations with Family, Peers, Social Context, and Risk Perceptions

Background: A number of correlates to adolescent substance use have been shown, yet their unique predictive influence is unclear. We investigated the incremental validity of demographics, family background, school variables, risk perception, parental alcohol attitudes, age of first alcohol use, peer group influence, and behavioral variables as they concurrently predicted last month alcohol use, binge drinking, and drunkenness experience frequency. Methods: Hierarchical multiple regression analyses in a sample of N = 743 adolescents (mean age = 15.01). Results: All predictors explained 26-40% of the total variance. Alcohol use was predicted by age, gender, having two working parents, academic family background, relationship to parents, relative risk perception, parental acceptance of alcohol use, age of first use, talking about positive aspects of alcohol, normality of alcohol use among peers, time spent with friends, and going out to clubs. Binge drinking was predicted by age, working parents, school problems, relative risk perception, parental alcohol acceptance, age of first use, talking about positive aspects of alcohol, time spent with friends, and going out to clubs. Drunkenness was predicted by age, relationship to parents, school problems, relative risk perception, age of first use, talking about positive aspects of alcohol, and going out to clubs. Conclusions: Researchers need to take the complexity of adolescent substance use into account when designing studies and interventions. Relative risk perception emerged as the strongest (positive) predictor, indicating that adolescents are able to rather accurately assess their own risk and risk awareness alone does not suffice to engage in protective behavior.

Mothering, Substance Use Disorders and Intergenerational Trauma Transmission: An Attachment-Based Perspective

Background: A growing body of research underlines that interpersonal trauma in childhood leads to heightened susceptibility for substance use disorders (SUDs) in later life. Little research has been conducted on parenting experiences of mothers in recovery from substance use, taking into account their own upbringing as a child and the potential aftermath of interpersonal childhood trauma. Methods: Through in-depth qualitative interviews, 23 mothers with SUDs reflected on parenting experiences and parent-child bonding, related to both their children and parents. Interviews were transcribed verbatim and data were analyzed adopting thematic analysis. Results: Throughout the narratives, consequences of trauma on mothers' sense of self and its subsequent impact on parenting arose as salient themes. Five latent mechanisms of intergenerational trauma transmission were identified: 1) early interpersonal childhood trauma experiences in mothers; 2) trauma as a precursor of substance use; 3) substance use as a (self-fooling) enabler of parental functioning; 4) continued substance use impacting parental functioning; and 5) dysfunctional parental functioning and its relational impact upon offspring. Discussion: Findings suggest disruptive attachment can increase the vulnerability for SUDs on the one hand, but can be an expression of underlying trauma on the other, hence serving as a covert mechanism by which trauma can be transmitted across generations. Results indicate the need for preventive, attachment-based and trauma-sensitive interventions targeted at disruptive intergenerational patterns.

Developmental Aspects of Glucose and Calcium Availability on the Persistence of Memory Function Over the Lifespan

An important aspect concerning the underlying nature of memory function is an understanding of how memories are acquired and lost. The stability, and ultimate demise, of memory over the lifespan of an organism remains a critical topic in determining the neurobiological mechanisms that mediate memory representations. This has important implications for the elucidation and treatment of neurodegenerative diseases such as Alzheimer's disease (AD). One important question in the context of preserving functional plasticity over the lifespan is the determination of the neurobiological structural and functional changes that contribute to the formation of memory during the juvenile time frame that might provide protection against later memory dysfunction by promoting the establishment of redundant neural pathways. The main question being, if memory formation during the juvenile period does strengthen and preserve memory stability over the lifespan, what are the neurobiological structural or functional substrates that mediate this effect? One neural attribute whose function may be altered with early life experience and provide a mechanism to preserve memory through the lifespan is glucose transport-linked calcium (Ca2+) buffering. Because peak increases in glucose utilization overlap with a timeframe during which spatial training can enhance later memory processing, it might be the case that learning-associated changes in glucose utilization would provide an important neural functional change to preserve memory function throughout the lifespan. The glucose transporters are proteins that are reduced in AD pathology and there is evidence that glucose reductions can impair Ca2+ buffering. In the absence of an appropriate supply of ATP, provided via glucose transport and glycolysis, Ca2+ levels can rise leading to neural vulnerability with ensuing pathological outcomes. In this review, we explore the hypothesis that enhancing glucose utilization with spatial training during the preadolescent period will provide a functional enhancement that regulates glucose-dependent Ca2+ signaling during aging or neurodegeneration and provide essential neural resources to preserve functional plasticity and memory function.

Translating Developmental Neuroscience to Understand Risk for Psychiatric Disorders

The transition from childhood to adulthood represents the developmental time frame in which the majority of psychiatric disorders emerge. Recent efforts to identify risk factors mediating the susceptibility to psychopathology have led to a heightened focus on both typical and atypical trajectories of neural circuit maturation. Mounting evidence has highlighted the immense neural plasticity apparent in the developing brain. Although in many cases adaptive, the capacity for neural circuit alteration also induces a state of vulnerability to environmental perturbations, such that early-life experiences have long-lasting implications for cognitive and emotional functioning in adulthood. The authors outline preclinical and neuroimaging studies of normative human brain circuit development, as well as parallel efforts covered in this issue of the Journal, to identify brain circuit alterations in psychiatric disorders that frequently emerge in developing populations. Continued translational research into the interactive effects of neurobiological development and external factors will be crucial for identifying early-life risk factors that may contribute to the emergence of psychiatric illness and provide the key to optimizing treatments.