The intersection of stress, drug abuse and development

Functional dissection of prenatal drug effects on baby brain and behavioral development

Prenatal drug exposure (PDE) is known to affect fetal brain development with documented long‐term consequences. Most studies of PDE effects on the brain are based on animal models. In this study, based on a large sample of 133 human neonates and leveraging a novel linear mixed‐effect model designed for intersubject variability analyses, we studied the effects of six prenatally exposed drugs (i.e., nicotine, alcohol, selective serotonin reuptake inhibitor, marijuana, cocaine, and opioids) on neonatal whole‐brain functional organization and compared them with five other critical nondrug variables (i.e., gestational age at birth/scan, sex, birth weight, and maternal depression). The behavioral implications were also examined. Magnitude‐wise, through summing across individual drug effects, our results highlighted ~5% of whole‐brain functional connections (FCs) affected by PDE, which was highly comparable with the combined effects of the five nond rug variables. Spatially, the detected PDE effects featured drug‐specific patterns with a common bias in higher‐order brain regions/networks. Regarding brain–behavioral relationships, the detected connections showing significant drug effects also demonstrated significant correlations with 3‐month behavioral outcomes. Further mediation analyses supported a mediation role of the detected brain FCs between PDE status and cognitive/language outcomes. Our findings of widespread, and spatially biased PDE effect patterns coupled with significant behavioral implications may hopefully stimulate more human‐based studies into effects of PDE on long‐term developmental outcomes.

Cognitive and Behavioral Impact on Children Exposed to Opioids During Pregnancy

The developmental impact of opioid use during pregnancy is a subject of ongoing debate. Short-term neonatal outcomes, such as lower birth weight and neonatal abstinence syndrome, are the most well-recognized outcomes. However, knowledge gaps exist regarding longer-term neurocognitive and mental health outcomes. In this article, we summarize an expert panel discussion that was held in April 2018 by the Substance Abuse and Mental Health Services Administration and attended by national experts in the field of perinatal opioid exposure and its impact on child development. Despite the challenges with research in this area, there is emerging literature revealing an association between neonates exposed to opioids in utero and longer-term adverse neurocognitive, behavioral, and developmental outcomes. Although adverse sequalae may not be apparent in the neonatal period, they may become more salient as children develop and reach preschool and school age. Multiple variables (genetic, environmental, and biological) result in a highly complex picture. The next steps and strategies to support families impacted by opioid use disorder are explored. Model programs are also considered, including integrated care for the child and mother, parenting supports, and augmentations to home visiting.

Longitudinal analysis of health outcomes after exposure to toxics, Willits California, 1991-2012: application of the cohort-period (cross-sequential) design

BACKGROUND

About 1963, a factory in Willits, Mendocino County (County), California added chrome plating to the manufacture of steel products. After years of residents reporting high illness rates, the State undertook a series of investigations. They found exposures had been high and warranted further research into possible health effects. Applying the seldom-used cross-sequential design, we tested if Willits had an excess rate of adverse health conditions, compared to people of the same sex and cohort living in the rest of county (ROC). This is the first report on long-term health outcomes for Willits.

METHODS

Hospital discharge data for 1991-2012 were searched to find admissions for people born between 1940 and 1989 who ever gave the County as their residence. Diagnoses and procedures were classified to Level 1 (body systems) of the Multi-level Clinical Classification Software (CCS). We analyzed 796,917 diagnoses and 289,980 procedures found on 117,799 admissions of 43,234 patients who lived in the County at some time between 1991 and 2012. Of these, 7,564 lived in Willits. We summarized data to the person-level then the group level over cohort-period (cross-sequential) to control the age by time relationship, then calculated incidence rates, relative risk, and excess case statistics, each with confidence limits. A secondary analysis focused on whether Willits differed markedly from the rest of County (ROC). Specifically, other than the presence of the Plant, did Willits differ so much that those differences could plausibly explain outcome differences?

RESULTS

Illness was excessive in the exposed group (Willits) compared to the unexposed (ROC). Overall number of excess cases attributable to living in Willits was estimated: Men, 301 (95% confidence limit (CL) 200-398), women: 696 (CL 569-820).

CONCLUSIONS

This study demonstrates the strength of the cross-sequential design. Willits and ROC had comparable disadvantages relative to the State. Yet, when stratified by cohort, Willits had more illness per population. Little is known about the health effect of chemicals used at Willits on a non-occupationally exposed population. We recommend a follow-up study to evaluate the long-term health of people who lived in Willits during childhood and the reproductive age.

Environmental pollutants and lifestyle factors induce oxidative stress and poor prenatal development

Developmental toxicity caused by exposure to a mixture of environmental pollutants has become a major health concern. Human-made chemicals, including xenoestrogens, pesticides and heavy metals, as well as unhealthy lifestyle behaviours, mainly tobacco smoking, alcohol consumption and medical drug abuse, are major factors that adversely influence prenatal development and increase susceptibility of offspring to diseases. There is evidence to suggest that the developmental toxicological mechanisms of chemicals and lifestyle factors involve the generation of reactive oxygen species (ROS) and cellular oxidative damage. Overproduction of ROS induces oxidative stress, a state where increased ROS generation overwhelms antioxidant protection and subsequently leads to oxidative damage of cellular macromolecules. Data on the involvement of oxidative stress in the mechanism of developmental toxicity following exposure to environmental pollutants are reviewed in an attempt to provide an updated basis for future studies on the toxic effect of such pollutants, particularly the notion of increased risk for developmental toxicity due to combined and cumulative exposure to various environmental pollutants. The aims of such studies are to better understand the mechanisms by which environmental pollutants adversely affect conceptus development and to elucidate the impact of cumulative exposures to multiple pollutants on post-natal development and health outcomes. Developmental toxicity caused by exposure to mixture of environmental pollutants has become a major health concern. Human-made chemicals, including xenoestrogens, pesticides and heavy metals, as well as unhealthy lifestyle behaviors, mainly tobacco smoking, alcohol consumption and medical drug abuse, are major factors that adversely influence prenatal development and increase the susceptibility of offspring to development complications and diseases. There is evidence to suggest that the developmental toxicological mechanisms of human-made chemicals and unhealthy lifestyle factors involve the generation of reactive oxygen species (ROS) and cellular oxidative damage. Overproduction of ROS induces oxidative stress, a state where increased generation of ROS overwhelms antioxidant protection and subsequently leads to oxidative damage of cellular macromolecules. Exposure to various environmental pollutants induces synergic and cumulative dose-additive adverse effects on prenatal development, pregnancy outcomes and neonate health. Data from the literature on the involvement of oxidative stress in the mechanism of developmental toxicity following in vivo exposure to environmental pollutants will be reviewed in an attempt to provide an updated basis for future studies on the toxic effect of such pollutants, particularly the notion of increased risk for developmental toxicity due to combined and cumulative exposure to various environmental pollutants. The aims of such studies are to better understand the mechanisms by which environmental pollutants adversely affect conceptus development and to elucidate the impact of cumulative exposures to multiple pollutants on postnatal development and health outcomes.

Consequences of prenatal substance use

BACKGROUND

Prenatal substance use is a major public health problem and a social morbidity, with consequences on the drug user and the offspring.

OBJECTIVE

This review focuses on the child and adolescent outcomes following in utero drug exposure.

METHODS

Studies on the effects of specific substances, legal and illegal; i.e., tobacco or nicotine, alcohol, marijuana, cocaine, opiates, and methamphetamine were evaluated and analyzed.

RESULTS

In general, manifestations of prenatal exposure to legal and illegal substances include varying deficits in birth anthropometric measurements, mild-to-moderate transient neurobehavioral alterations in infancy and long-term behavioral problems noted from early childhood to adolescence. Severity of expression of behavioral problems is influenced by environmental factors. Further, behavioral alterations following in utero drug exposure often exist with mental health co-morbidities.

CONCLUSION

Because of the long-term consequences of prenatal drug exposure on child and adolescent mental health, health providers need to promote substance use prevention, screen for exposure effects and provide or refer affected youths for intervention services. Preventive measures and treatment should consider other factors that may further increase the risk of psychopathology in the exposed children.

Increasing prenatal care and healthy behaviors in pregnant substance users

Evidence suggests that prenatal care, healthy behaviors such as exercise and nutrition, and general stress level are associated with fetal and maternal health but there is a relative dearth of research on interventions to improve these factors in pregnant substance users. Two hundred pregnant substance users entering outpatient substance abuse treatment were randomized to receive either three individual sessions of Motivational Enhancement Therapy for pregnant substance users (MET-PS) or the first three individual sessions normally provided by the program. The present study evaluated the relative efficacy of MET-PS, compared to treatment as usual, on modifiable healthy behaviors and the impact of treatment when the groups were pooled. The results suggest that MET-PS was not more effective than treatment as usual in improving modifiable healthy behaviors. When the treatment groups were pooled, the results suggest that there were significant increases in prenatal care utilization and prenatal/multi-vitamin and water consumption, and a significant decrease in stress. Limitations and recommendations for further research are discussed.

Getting the mix right: family, community and social policy interventions to improve outcomes for young people at risk of substance misuse

Societal responses to the existence of substance misuse fluctuate between harm minimisation and prohibition. Both approaches are predominantly downstream reactions to substance misuse that focus on the supply of harmful substances and the containment of misuse through treatment, rehabilitation or punishment. Until recently, little attention has been paid to the upstream individual, family, relationship, community or societal antecedents of substance misuse (which often overlap with those for other adverse life outcomes, such as unemployment, antisocial personality disorder and mental health problems) that have operated during earlier life. A growing body of evidence highlights the overlapping biological and experiential antecedents for substance abuse and other poor outcomes as well as the trajectory-changing protective factors that can prevent risks being translated into destiny. Risk minimisation and protection enhancement embedded in family and social systems are the essential building blocks of a set of early intervention strategies that begin antenatally and continue through the developing years of childhood, adolescence and young adult life, that have been shown to be effective in improving many outcomes in development, health and well-being. Much remains to be done to enable the promise of effective universal and targeted early intervention to be translated into policies, programs and practices that could be life-changing for citizens bogged in the mire of substance misuse and their children. Realistic, timely investment, influenced by the best scientific evidence indicating what works, for whom, under what circumstances, an increased degree of collaboration within and between governments and their agencies to enable "whole of government" responses in partnership with community-based initiatives are essential along with investments in multidisciplinary program evaluation research that will enable evidence-informed policy decisions to be tailored to the needs of individual countries.

Prenatal exposure to drugs: effects on brain development and implications for policy and education

The effects of prenatal exposure to drugs on brain development are complex and are modulated by the timing, dose and route of drug exposure. It is difficult to assess these effects in clinical cohorts as these are beset with problems such as multiple exposures and difficulties in documenting use patterns. This can lead to misinterpretation of research findings by the general public, the media and policy makers, who may mistakenly assume that the legal status of a drug correlates with its biological impact on fetal brain development and long-term clinical outcomes. It is important to close the gap between what science tells us about the impact of prenatal drug exposure on the fetus and the mother and what we do programmatically with regard to at-risk populations.

Adolescent neurological development and its implications for adolescent substance use prevention

Recent technological advancements have facilitated the study of adolescent neurological development and its implications for adolescent decision-making and behavior. This article reviews findings from the adolescent neurodevelopment and substance use prevention literatures. It also discusses how findings from these two distinct areas of adolescent development can complement each other and be used to build more developmentally appropriate interventions for preventing adolescent substance use. Specifically, a combination of child-centered and family-based strategies is advocated based on extant neurological and prevention literature. EDITORS' STRATEGIC IMPLICATIONS: Researchers are encouraged to take up the authors' challenge and study the links between adolescent neurological development/decision making ability and the long term efficacy of comprehensive interventions for preventing adolescent substance use.

Association between the recombinant human serotonin transporter linked promoter region polymorphism and behavior in rhesus macaques during a separation paradigm

Human studies have suggested an association between a variable length polymorphism in the serotonin transporter gene promoter region and vulnerability to anxiety and depression. Relative to the long (l) allele, the short (s) allele increases the risk of developing depression in individuals exposed to stressful life events. An orthologue of the human variant is present in rhesus macaques and allows for studies in animals exposed to stress. Here, we used an established model of early life stress exposure, in which rhesus macaques are raised without adults in a group of peers (peer-only reared [PR]), or with their mothers. At 6 months of age, animals were subjected to 4-day long social separations for 4 consecutive weeks, with 3 days of reunion in between. Data were collected during both the acute (Day 1) and chronic phases (Days 2–4) of separation. Behavioral factors were separately extracted for each phase of separation. For acute separation, the behavioral factors generated were despair and behavioral pathology and, for the chronic phase despair, agitation, and behavioral pathology. During both phases of social separation, PR l/s animals were more likely to exhibit pathological behaviors, whereas PR l/l monkeys show higher levels of despair compared to the other three groups. These findings indicate that early stress affects the behavioral response to separation differently as a function of recombinant human serotonin transporter linked polymorphic repeat genotype and suggest that carriers of the s allele are not only more anxious but may also be more vulnerable to developing behavioral pathology in the face of chronic adversity.

Waved-1 mutant mice are hypersensitive to the locomotor actions of cocaine

Transforming growth factor-alpha (TGFalpha) is a well-known regulator of many developmental processes, and is expressed heavily in basal forebrain and striatal regions. When TGFalpha is reduced in Waved-1 (Wa-1) mutant mice, brain anatomy, biogenic amines, stress response, and behavior are normal prior to, but altered following puberty. As an initial screen for possible alterations in nigrostriatal and mesolimbic dopamine (DA) systems, we tested adult Wa-1 mutant mice in an open field, following acute injection with cocaine (15 mg/kg). Wa-1 mice exhibited significantly greater ambulatory distance, number of ambulatory episodes, and cocaine-induced motor stereotypies than do controls. These data indicate that adult Wa-1 mice are hypersensitive to the locomotor effects of cocaine and provide a new potential link between neurodevelopmental processes and adult psychostimulant responsiveness.

Mediators of the stress-substance-use relationship in urban male adolescents

Exposure to chronic or severe acute stressors throughout the lifespan has been linked with numerous negative behavioral, emotional, cognitive, and physical consequences. Adolescence is considered to be a particularly vulnerable period given that the brain is experiencing dramatic developmental change during this time. The present study examined a sample of adolescents (N=125) considered to be at high risk for stress exposures and drug use by virtue of their environment and low income levels to identify possible neurocognitive (i.e., impulsivity, delay of gratification, emotional perception, and risky decision-making) and social competency mechanisms that may mediate this relationship. Using Mplus, a mediational model was tested using full information maximum likelihood estimates. Risky decision-making and poor social competency skills were related to previous stressful experiences; however, only social competencies mediated the effect of stressors on reports of past year marijuana, alcohol, and polydrug use. As such, stress appears to exert its negative impact through alterations in abilities to generate and execute prosocial decisions and behaviors. Interventions that directly address the effects of stress on social competencies may be especially important for children who have experienced adversity including those exposed to parental divorce, parental psychopathology, neglect or abuse, parental death, and poverty.

Is the brain hormonally imprintable?

Hormonal imprinting develops at the first encounter between the target hormone and its developing receptor in the perinatal critical period. This determines the binding and response capacity of the receptor-signal transduction system and hormone production of cells for life. Molecules similar to the hormone and excess or absence of the target hormone cause faulty imprinting with lifelong consequences. Prenatal or neonatal imprinting with opiates, other drugs and prenatal stress have harmful consequences on the adult brain. Perinatal imprinting with endorphin or serotonin decreases the serotonin level of the brain while increasing sexual activity and (as in the case of endorphin) aggression. Endorphin or serotonin antagonist treatment at weaning (late imprinting) also significantly reduces the serotonin content of the brain. Backed by literary data, these observations are discussed, and the possible consequences of medical treatments are shown. The paper concludes that an excess of molecules produced by the brain itself can provoke perinatal imprinting, and it points to the possibility of late imprinting of the brain by receptor level acting agents, including a brain product (endorphin).

The impact of emotional stress early in life on adult voluntary ethanol intake-results of maternal separation in rats

The combination of genetic and environmental factors determines the individual vulnerability for excessive ethanol intake, possibly leading to dependence. The environmental influences early in life represent examples of determinant factors for adult behaviour and can be protective as well as risk factors. Maternal separation is one model to examine the long-term consequences of early environmental experiences on neurochemistry and behaviour, including drug-taking behaviour in experimental animals. In the present review, findings from studies using repeated short and prolonged periods of maternal separation, with emphasis on effects on voluntary ethanol intake in rats with or without a genetic predisposition for high voluntary ethanol intake, are summarized. Despite some contradictory results, the general picture emerging shows that short periods of maternal separation during the postnatal period result in a lower adult voluntary ethanol intake in male rats. Prolonged periods of maternal separation were found to induce a high voluntary ethanol intake in male rats, including rats with a genetic predisposition for high ethanol intake. Results from the literature also show that changes were not just related to time of separation but were also related to the degree of handling. Interestingly, in terms of voluntary ethanol intake, female rats were generally not affected by postnatal maternal separation. The reasons for these sex differences need further investigation. In terms of neurobiological consequences of maternal separation, conclusive data are sparse and one of the future challenges will, therefore, be to identify and characterize underlying neurobiological mechanisms, especially in the individual animal.

Neighborhood disorder, psychological distress, and heavy drinking

Studies show that residents of disadvantaged neighborhoods drink more heavily than residents of more affluent neighborhoods. However, explanations for this association are not well developed. Using data collected from a sample of low-income women with children from Boston, Chicago, and San Antonio, we explore the possibility that perceptions of neighborhood disorder encourage heavy drinking. Drawing on Conger's (Q. J. Stud. Alcohol 17 (1956) 296) tension reduction hypothesis, we propose that the stress of living in a neighborhood characterized by problems with drugs, crime, teen pregnancy, unemployment, idle youth, abandoned houses, and unresponsive police can be psychologically distressing and lead some people to consume alcohol as a means of palliative escape, to regulate feelings of anxiety and depression. In support of the tension reduction hypothesis, we find that the positive association between neighborhood disorder and heavy drinking is largely mediated by anxiety and depression.

Maternal smoking, drinking or cannabis use during pregnancy and neurobehavioral and cognitive functioning in human offspring

Teratological investigations have demonstrated that agents that are relatively harmless to the mother may have significant negative consequences to the fetus. Among these agents, prenatal alcohol, nicotine or cannabis exposure have been related to adverse offspring outcomes. Although there is a relatively extensive body of literature that has focused upon birth and behavioral outcomes in newborns and infants after prenatal exposure to maternal smoking, drinking and, to a lesser extent, cannabis use, information on neurobehavioral and cognitive teratogenic findings beyond these early ages is still quite limited. Furthermore, most studies have focused on prenatal exposure to heavy levels of smoking, drinking or cannabis use. Few recent studies have paid attention to low or moderate levels of exposure to these substances. This review endeavors to provide an overview of such studies, and includes animal findings and potential mechanisms that may explain the mostly subtle effects found on neurobehavioral and cognitive outcomes. It is concluded that prenatal exposure to either maternal smoking, alcohol or cannabis use is related to some common neurobehavioral and cognitive outcomes, including symptoms of ADHD (inattention, impulsivity), increased externalizing behavior, decreased general cognitive functioning, and deficits in learning and memory tasks.

Bioscience-bioethics and life factors affecting reproduction with special reference to the Indigenous Australian population

The demand for equality of recognition or respect is the dominant passion of modernity. The 20th century experienced a giant leap in technological inventiveness and ruthless use of technological power. In the 21st century, human welfare and environmental wellbeing demand fundamental political appraisal. We have the means, if we choose, to eradicate poverty and to responsibly protect the global environment. However, economic, political and cultural systems act to differentially allocate the benefits and risks for growth between socioeconomic groups. For example, it is a matter of pride that the neonatal mortality rate in affluent societies has dropped substantially since the late 1970s. However, the level of infant mortality (three times the national average) and low birthweight (13%) among the Indigenous Australian population is the highest in the country. With hindsight we now know that is the inevitable legacy of Australia’s colonial history. Chronic physical and psychological stress is recognized as an important etiological factor in many lifestyle diseases of the cardiovascular, immune and reproductive systems. Diseases of adaptation are further advanced by non-adaptive lifestyle choices, depression, alcoholism and other drug dependencies. This review describes the principles of bioscience ethics and targets equity issues as they affect human reproduction across generations with particular reference to the Indigenous population of Australia. The review also considers ways we may advance global and cultural maturity from the Indigenous Australian perspective and proposes an ecologically based model of preventative care. If we are to embrace fundamental social change and protect future children without threatening parents’ basic freedoms, then new beliefs and priorities – based on a compassionate understanding of biological systems – must evolve from the general public. Belief in human rights arising from a sense of human dignity is a collective outcome originating from individual commitment. The golden rule; that is, Nature’s principle of reciprocity, is fundamental in bridging the gap between knowledge and effective action.

Smoking, stress, and negative affect: correlation, causation, and context across stages of smoking

This transdisciplinary review of the literature addresses the questions, Do stress and negative affect (NA) promote smoking? and Does smoking genuinely relieve stress and NA? Drawing on both human and animal literatures, the authors examine these questions across three developmental stages of smoking--initiation, maintenance, and relapse. Methodological and conceptual distinctions relating to within- and between-subjects levels of analyses are emphasized throughout the review. Potential mechanisms underlying links between stress and NA and smoking are also reviewed. Relative to direct-effect explanations, the authors argue that contextual mediator-moderator approaches hold greater potential for elucidating complex associations between NA and stress and smoking. The authors conclude with recommendations for research initiatives that draw on more sophisticated theories and methodologies.