Reactivity and regulation in children prenatally exposed to cocaine

Opioid-induced dysbiosis of maternal gut microbiota during gestation alters offspring gut microbiota and pain sensitivity

There has been a rapid increase in neonates born with a history of prenatal opioid exposure. How prenatal opioid exposure affects pain sensitivity in offspring is of interest, as this may perpetuate the opioid epidemic. While few studies have reported hypersensitivity to thermal pain, potential mechanisms have not been described. This study posits that alterations in the gut microbiome may underly hypersensitivity to pain in prenatally methadone-exposed 3-week-old male offspring, which were generated using a mouse model of prenatal methadone exposure. Fecal samples collected from dams and their offspring were subjected to 16s rRNA sequencing. Thermal and mechanical pain were assessed using the tail flick and Von Frey assays. Transcriptomic changes in whole brain samples of opioid or saline-exposed offspring were investigated using RNA-sequencing, and midbrain sections from these animals were subjected to qPCR profiling of genes related to neuropathic and inflammatory pain pathways. Prenatal methadone exposure increased sensitivity to thermal and mechanical pain and elevated serum levels of IL-17a. Taxonomical analysis revealed that prenatal methadone exposure resulted in significant alterations in fecal gut microbiota composition, including depletion of Lactobacillus, Bifidobacterium, and Lachnospiracea sp and increased relative abundance of Akkermansia, Clostridium sensu stricto 1, and Lachnoclostridium. Supplementation of the probiotic VSL#3 in dams rescued hypersensitivity to thermal and mechanical pain in prenatally methadone-exposed offspring. Similarly, cross-fostering prenatally methadone-exposed offspring to control dams also attenuated hypersensitivity to thermal pain in opioid-exposed offspring. Modulation of the maternal and neonatal gut microbiome with probiotics resulted in transcriptional changes in genes related to neuropathic and immune-related signaling in whole brain and midbrain samples of prenatally methadone-exposed offspring. Together, our work provides compelling evidence of the gut-brain-axis in mediating pain sensitivity in prenatally opioid-exposed offspring.

Developmental Pathways from Prenatal Substance Exposure to Reactive Aggression

Few studies have examined etiological pathways from prenatal substance exposure to adolescent reactive aggression. We tested a conceptual model that included hypothesized pathways from prenatal substance exposure to adolescent aggression via autonomic reactivity and violence exposure from infancy to early school age and maternal harshness across early childhood. The sample included 216 families (106 boys) who primarily self-identified as Black or Mixed Race. Results supported the hypothesized path from violence exposure across early childhood and early school age to school age autonomic reactivity and early adolescent reactive aggression. There was also a significant interaction effect of sympathetic and parasympathetic reactivity on adolescent reactive aggression, with sympathetic arousal and parasympathetic suppression at early school age associated with higher reactive relational and physical aggression in adolescence. Results emphasize the importance of early experiences and autonomic nervous system changes in contributing to the cascade of risk for reactive aggression in early adolescence.

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.

Gender Differences in the Outcome of Offspring Prenatally Exposed to Drugs of Abuse

Despite great efforts to warn pregnant women that drugs of abuse impact development of the embryo and the fetus, the use of legal and illegal drugs by childbearing women is still a major public health concern. In parallel with well-established teratogenic effects elicited by some drugs of abuse, epidemiological studies show that certain psychoactive substances do not induce birth defects but lead to subtle neurobehavioral alterations in the offspring that manifest as early as during infancy. Although gender differences in offspring susceptibility have not been fully investigated, a number of longitudinal studies indicate that male and female progeny exposed in utero to drugs of abuse show different vulnerabilities to deleterious effects of these substances in cognitive, executive, and behavioral domains. Here, we briefly review the existing literature focusing on gender differences in the neurobehavioral consequences of maternal exposure to drugs of abuse. Overall, the data strongly indicate that male exposed progeny are more susceptible than female to dysfunctions in cognitive processing and emotional regulation. However, insights into the mechanisms determining this natural phenomenon are not currently available. Our analysis prompts future investigations to implement clinical studies including the influence of gender/sex as a biological variable in the outcome of offspring prenatally exposed to drugs of abuse.

Longitudinal changes of amygdala functional connectivity in adolescents prenatally exposed to cocaine

BACKGROUND

Prenatal cocaine exposure (PCE) is associated with arousal dysregulation, but interactions between exposure and age are rarely investigated directly with longitudinal study designs. Our previous study had examined task-elicited emotional arousal and noted persistently high amygdala activations in the development of adolescents with PCE. However, while externally imposed emotional arousal could be considered a "state" effect depending on specific task stimuli, it is still unclear whether similar developmental alterations extend to intrinsic functional connectivity (FC), reflecting more of a "trait" effect.

METHODS

We used a longitudinal design and analyzed resting-state functional magnetic resonance imaging data acquired twice from 25 adolescents with PCE and 16 non-exposed controls. Both groups were each scanned first at the mean age of 14.3 and then again at 16.6 years. Seeding in bilateral amygdalae and comparing the 2^nd scan with the 1^st, we examined the interaction effect between PCE and age on FCs in the emotional network.

RESULTS

Compared with the younger age, we observed a generally decreased FC in the emotional network of the control group at the older age, but these FCs were generally increased at the older age in this same network of the PCE group. Additionally, this interaction effect of exposure by age in the right fusiform was positively correlated with the emotional interference imposed by external task stimuli.

CONCLUSIONS

These results provided additional data directly characterizing developmental changes in the emotional network of adolescents with PCE, complementing and extending the notion of a PCE-associated long-term teratogenic effect on arousal regulation.

An examination of the association between prenatal cocaine exposure and brain activation measures of arousal and attention in young adults: An fMRI study using the Attention Network Task

Prenatal drug exposure, including cocaine, alcohol, marijuana, and tobacco, is associated with deficits in behavioral regulation and attention. Using fMRI, the objective of this study was to characterize the association between prenatal cocaine exposure (PCE) and the underlying neural substrates associated with behavioral outcomes of attention. Forty-seven young adults were recruited for this study from the ongoing Maternal Health Practices and Child Development (MHPCD) Project, a longitudinal study of the effects of PCE on growth, behavior, and cognitive function. Three groups were compared: 1) prenatal exposure to cocaine, alcohol, marijuana, and tobacco (CAMT, n = 15), 2) prenatal exposure to alcohol, marijuana, and tobacco (AMT, n = 17), and 3) no prenatal exposure to drugs (Controls, n = 15). Subjects were frequency matched on gender, race, handedness, and 15-year IQ. This study used the theoretical model proposed by Posner and Peterson (1990), which posits three dissociable components of attention: alerting, orienting, and executive attention. Subjects completed a functional MRI (fMRI) scan while performing the Attention Network Task, a validated neuroimaging measure of the 3-network model of attention. Behavioral and fMRI data revealed no associations between PCE and task accuracy, speed of processing, or activation in key brain regions associated with each of the attention networks. The results of this study show that any subtle differences in brain function associated with PCE are not detectable using the ANT task and fMRI. These results should be interpreted in the context of other studies that have found associations between PCE and arousal with emotionally arousing stimuli, compared to this study that found no associations using emotionally neutral stimuli.

Gender-related Differences in Inhibitory Control and Sustained Attention among Adolescents with Prenatal Cocaine Exposure

Adolescence and prenatal cocaine exposure can impact risk-taking. In this study, we evaluated risk-taking and gender-related differences in adolescents with prenatal cocaine exposure in terms of electrophysiological correlates of inhibitory control and sustained attention. No differences related to gender were found within measures of risk-taking, or electrophysiological response relating to risk-taking. Greater responses during inhibition versus attention trials support previous studies, with boys showing the largest responses. Gender-related differences were found when comparing the trials before and after frustration was induced, with greater initial attention indices for girls in both trial types and greater sustained attention for both genders during inhibition trials and for boys during attention trials. These data suggest neural correlates of response inhibition show important gender-related differences in this population. Considering these relationships allows us to further understand underlying processes among adolescents who, as a group, tend to be more inclined toward greater risk behaviors.

Parental Substance Abuse As an Early Traumatic Event. Preliminary Findings on Neuropsychological and Personality Functioning in Young Drug Addicts Exposed to Drugs Early

Parental substance use is a major risk factor for child development, heightening the risk of drug problems in adolescence and young adulthood, and exposing offspring to several types of traumatic events. First, prenatal drug exposure can be considered a form of trauma itself, with subtle but long-lasting sequelae at the neuro-behavioral level. Second, parents' addiction often entails a childrearing environment characterized by poor parenting skills, disadvantaged contexts and adverse childhood experiences (ACEs), leading to dysfunctional outcomes. Young adults born from/raised by parents with drug problems and diagnosed with a Substance Used Disorder (SUD) themselves might display a particularly severe condition in terms of cognitive deficits and impaired personality function. This preliminary study aims to investigate the role of early exposure to drugs as a traumatic event, capable of affecting the psychological status of young drug addicts. In particular, it intends to examine the neuropsychological functioning and personality profile of young adults with severe SUDs who were exposed to drugs early in their family context. The research involved three groups, each consisting of 15 young adults (aged 18–24): a group of inpatients diagnosed with SUDs and exposed to drugs early, a comparison group of non-exposed inpatients and a group of non-exposed youth without SUDs. A neuropsychological battery (Esame Neuropsicologico Breve-2), an assessment procedure for personality disorders (Shedler-Westen Assessment Procedure-200) and the Symptom CheckList-90-Revised were administered. According to present preliminary results, young drug addicts exposed to drugs during their developmental age were characterized by elevated rates of neuropsychological impairments, especially at the expense of attentive and executive functions (EF); personality disorders were also common but did not differentiate them from non-exposed youth with SUDs. Alternative multi-focused prevention and intervention programs are needed for children of drug-misusing parents, addressing EF and adopting a trauma-focused approach.

Longitudinal changes of amygdala and default mode activation in adolescents prenatally exposed to cocaine

Prenatal cocaine exposure (PCE) is associated with long-term and negative effect on arousal regulation. Recent neuroimaging studies have examined brain mechanisms related to arousal dysregulation with cross-sectional experimental designs; but longitudinal changes in the brain, reflecting group differences in neurodevelopment, have never been directly examined. To directly assess the interaction of PCE and neurodevelopment, the present study used a longitudinal design to analyze functional magnetic resonance imaging (fMRI) data collected from 33 adolescents (21 with PCE and 12 non-exposed controls) while they performed the same working memory task with emotional distracters at two points in time. The mean age of participants was 14.3 years at time_1 and 16.7 years at time_2. With confounding factors statistically controlled, the fMRI data revealed significant exposure-by-time interaction in the activations of the amygdala and default mode network (DMN). For the control adolescents, brain activations associated with emotional arousal (amygdala) and cognitive effort (DMN) were both reduced at time_2 as compared to that at time_1. However, these activation reductions were not observed in the PCE group, indicating persistently high levels of emotional arousal and cognitive effort. In addition, correlations between longitudinal changes in the brain and in behavior have shown that adolescents with persistently high emotional arousal were more likely in need of high cognitive effort; and their cognitive performance was more likely to be affected by distractive challenges. The present results complement and extend previous findings from cross-sectional studies with further evidence supporting the view of PCE associated long-term teratogenic effects on arousal regulation.

Prenatal substance exposure: What predicts behavioral resilience by early adolescence?

Understanding behavioral resilience among at-risk adolescents may guide public policy decisions and future programs. We examined factors predicting behavioral resilience following intrauterine substance exposure in a prospective longitudinal birth-cohort study of 136 early adolescents (ages 12.4-15.9 years) at risk for poor behavioral outcomes. We defined behavioral resilience as a composite measure of lack of early substance use initiation (before age 14), lack of risky sexual behavior, or lack of delinquency. Intrauterine substance exposures included in this analysis were cocaine, tobacco, alcohol, and marijuana. We recruited participants from Boston Medical Center as mother-infant dyads between 1990 and 1993. The majority of the sample was African American/Caribbean (88%) and 49% female. In bivariate analyses, none and lower intrauterine cocaine exposure level predicted resilience compared with higher cocaine exposure, but this effect was not found in an adjusted model. Instead, strict caregiver supervision (adjusted odds ratio [AOR] = 6.02, 95% confidence interval (CI) [1.90, 19.00], p = .002), lower violence exposure (AOR = 4.07, 95% CI [1.77, 9.38], p < .001), and absence of intrauterine tobacco exposure (AOR = 3.71, 95% CI [1.28, 10.74], p = .02) predicted behavioral resilience. In conclusion, caregiver supervision in early adolescence, lower violence exposure in childhood, and lack of intrauterine tobacco exposure predicted behavioral resilience among a cohort of early adolescents with significant social and environmental risk. Future interventions should work to enhance parental supervision as a way to mitigate the effects of adversity on high-risk groups of adolescents. (PsycINFO Database Record

Prenatal cocaine exposure differentially affects stress responses in girls and boys: associations with future substance use

Prenatal cocaine exposure may affect developing stress response systems in youth, potentially creating risk for substance use in adolescence. Further, pathways from prenatal risk to future substance use may differ for girls versus boys. The present longitudinal study examined multiple biobehavioral measures, including heart rate, blood pressure, emotion, and salivary cortisol and salivary alpha amylase (sAA), in response to a stressor in 193 low-income 14- to 17-year-olds, half of whom were prenatally cocaine exposed (PCE). Youth's lifetime substance use was assessed with self-report, interview, and urine toxicology/breathalyzer at Time 1 and at Time 2 (6-12 months later). PCE × Gender interactions were found predicting anxiety, anger, and sadness responses to the stressor, with PCE girls showing heightened responses as compared to PCE boys on these indicators. Stress Response × Gender interactions were found predicting Time 2 substance use in youth (controlling for Time 1 use) for sAA and sadness; for girls, heightened sadness responses predicted substance use, but for boys, dampened sAA responses predicted substance use. Findings suggest distinct biobehavioral stress response risk profiles for boys and girls, with heightened arousal for girls and blunted arousal for boys associated with prenatal risk and future substance use outcomes.

Conceptualizing prenatal care: recent research and the application of Tae-Kyo, Korean traditional beliefs and practices

The value of prenatal care has long been recognized by various cultures. The author's purpose in this article is to propose a framework to conceptualize prenatal care using the traditional Korean practice of prenatal care called Tae-Kyo, which means education for the fetus. The philosophy of Tae-Kyo shows the importance of children's development from the very beginning of life and indicates the moral and social responsibilities of pregnant women, family members, and communities in delivering healthy babies. This comprehensive view implies a framework for conceptualizing prenatal care that encompasses multidimensional aspects of prenatal care.

Empathic responsivity at 3 years of age in a sample of cocaine-exposed children

This study examined the association between prenatal exposure to cocaine and behavioral and physiological responsivity. Participants were 216 mother-infant dyads (116 cocaine exposed-CE, 100 nonexposed-NCE) recruited at birth. Measures of heart rate (HR) and respiratory sinus arrhythmia (RSA) were obtained during baseline and during a task designed to elicit empathy (exposure to infant crying). When the effects of prenatal cocaine use were examined in the context of polydrug use, results of model testing indicated that lower gestational age, prenatal exposure to cocaine and postnatal exposure to alcohol were each associated with a reduced suppression of RSA during the empathy task. These findings provide additional support for an association between prenatal cocaine exposure and dysregulation during early childhood during affect-eliciting environmental challenges.

Behavior problems among cocaine exposed children: role of physiological regulation and parenting

This study examined interrelations between prenatal cocaine exposure, child autonomic regulation, parenting behavior and child sex on parent-reported behavior problems at 36 months of age. We hypothesized that respiratory sinus arrhythmia (RSA) at 13 months of age would mediate the relation between cocaine exposure and behavior problems. We also hypothesized that child sex, maternal negative affect, and maternal sensitivity observed at 13 months of age would moderate the relation between RSA and behavior problems. Results revealed that cocaine exposure predicted low baseline RSA and low RSA withdrawal during a negative affect task. Low baseline RSA, in turn, predicted fewer behavior problems offering support for an indirect association between cocaine exposure and behavior problems. The association between baseline RSA and behavior problems was further moderated by maternal negative affect such that high baseline RSA was more strongly related to behavior problems under conditions of high compared to low maternal negative affect. Results also revealed a near significant trend for baseline RSA to be more strongly related to behavior problems among boys than girls. These findings highlight several possible pathways toward behavior problems among cocaine exposed children.

Adolescent risk-taking as a function of prenatal cocaine exposure and biological sex

OBJECTIVE

To examine the effects of prenatal cocaine exposure and biological sex on adolescent risk-taking while controlling for early environmental risk.

METHODS

Adolescents (n=114, mean age=16) were grouped according to high and low risk-taking propensity as measured by the Balloon Analogue Risk Task (BART). Prenatal cocaine exposure was assessed at birth, while environmental risk was assessed at three points during early childhood.

RESULTS

A binary regression analysis indicated that males were 3.5 times more likely than females to be high risk-takers. Biological sex and prenatal cocaine exposure interacted such that exposed males were most likely to be high risk-takers while exposed females were the least likely to be high risk-takers. This pattern held after controlling for prenatal alcohol exposure and early environmental risk. Early environmental risk did not predict adolescent risk-taking.

CONCLUSIONS

These findings complement and extend earlier research demonstrating that prenatal cocaine exposure interacts with biological sex in domains related to inhibitory control, emotion regulation, antisocial behavior, and health risk behaviors during preadolescence.

Examining the relationships between prenatal methamphetamine exposure, early adversity, and child neurobehavioral disinhibition

Methamphetamine use is a growing problem among pregnant women in the United States. Many negative consequences of methamphetamine use have been documented for the users, but little research has examined the long-term association between prenatal methamphetamine exposure (PME) and childhood outcomes. The current study examined the extent to which PME was predictive of childhood neurobehavioral disinhibition (ND), as well as the extent to which early adversity mediated this relationship. A sample of 320 mother-infant dyads (162 PME) was followed from birth through 6.5 years of age. ND was conceptualized as a two factor model consisting of deficits in (a) behavioral and emotional control, and (b) executive function. PME was associated with behavioral and emotional control at 5 years, which was associated with executive function deficits at 6.5 years. Early adversity (birth through year 3) significantly mediated the relationship between PME and ND. Associations with previous research and implications for prevention are discussed.

Prenatal cocaine exposure alters functional activation in the ventral prefrontal cortex and its structural connectivity with the amygdala

Prenatal cocaine exposure (PCE) is associated with arousal dysregulation, and alterations of amygdala activity in response to emotional arousal have previously been reported. However, voluntary regulation of emotional affect, enabling appropriate neural response to different streams of stimuli, must also engage prefrontal regions, yet the impact of PCE on these prefrontal mechanisms has not been investigated. Recent neuroimaging studies have shown the involvement of ventral prefrontal cortex (vPFC) in the modulation of amygdala reactivity and the mediation of effective emotional regulation. Based on these findings, using functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), the present study compared functional activations of the vPFC as well as its structural connectivity with the amygdala between groups of PCE and control adolescents. In a working memory task with emotional distracters, the PCE adolescents exhibited less capability of increasing their vPFC activation in response to increased memory load, which corresponded with their less suppressed amygdala activation. Reduced structural connectivity between the vPFC and the amygdala was also observed from DTI measurement in the PCE group. In addition, correlations between amygdala activation and (i) vPFC activation, as well as (ii) amygdala-vPFC structural connectivity, were observed in the control but not in the PCE group. These data complement previous findings of the impact of PCE on the activity of the amygdala and extend our understanding of the neurobiological mechanisms underlying the effect of PCE on arousal dysregulation reported in human and animal studies.

Externalizing behavior problems among polydrug cocaine-exposed children: Indirect pathways via maternal harshness and self-regulation in early childhood

This study examined direct and indirect associations between prenatal cocaine exposure (CE) and children's externalizing problems in kindergarten via higher maternal harshness and lower self-regulation in early childhood. Other environmental risk variables, such as child exposure to community violence and experience of hunger, were used as additional predictors. The sample consisted of 216 mother-infant dyads recruited at delivery from local area hospitals (116 cocaine-exposed, 100 nonexposed). Maternal harshness was coded from observations of mother-toddler interactions at 2 years of age, and children's self-regulation was measured at 3 years of age using several laboratory paradigms. Maternal reports of externalizing behavior problems were obtained at both time points and at kindergarten. Teacher reports were obtained and classroom observations of externalizing behaviors were conducted in the kindergarten classroom. Results indicated significant indirect associations between CE and maternal reports of externalizing problems via higher maternal harshness at 2 years and higher externalizing problems at 3 years of child age. A second indirect path from CE to externalizing problems in the school setting via higher maternal harshness at 2 years and lower self-regulation at 3 years was also significant. There were significant associations between community violence exposure and maternal reports of externalizing problems, and between hunger and externalizing problems in the school setting. Results highlight the role of parenting and self-regulation in early childhood as critical process variables in the indirect association between CE and externalizing behavior problems in kindergarten.

Regional brain morphometry and impulsivity in adolescents following prenatal exposure to cocaine and tobacco

IMPORTANCE

Animal studies have suggested that prenatal cocaine exposure (PCE) deleteriously influences the developing nervous system, in part attributable to its site of action in blocking the function of monoamine reuptake transporters, increasing synaptic levels of serotonin and dopamine.

OBJECTIVE

To examine the brain morphologic features and associated impulsive behaviors in adolescents following prenatal exposure to cocaine and/or tobacco.

DESIGN

Magnetic resonance imaging data and behavioral measures were collected from adolescents followed up longitudinally in the Maternal Lifestyle Study.

SETTING

A hospital-based research center.

PARTICIPANTS

A total of 40 adolescent participants aged 13 to 15 years were recruited, 20 without PCE and 20 with PCE; a subset of each group additionally had tobacco exposure. Participants were selected and matched based on head circumference at birth, gestational age, maternal alcohol use, age, sex, race/ethnicity, IQ, family poverty, and socioeconomic status.

MAIN OUTCOME MEASURES

Subcortical volumetric measures of the thalamus, caudate, putamen, pallidum, hippocampus, amygdala, and nucleus accumbens; cortical thickness measures of the dorsolateral prefrontal cortex and ventral medial prefrontal cortex; and impulsivity assessed by Conners' Continuous Performance Test and the Sensation Seeking Scale for Children.

RESULTS

After controlling for covariates, cortical thickness of the right dorsolateral prefrontal cortex was significantly thinner in adolescents following PCE (P = .03), whereas the pallidum volume was smaller in adolescents following prenatal tobacco exposure (P = .03). Impulsivity was correlated with thalamic volume following either PCE (P = .05) or prenatal tobacco exposure (P = .04).

CONCLUSIONS AND RELEVANCE

Prenatal cocaine or tobacco exposure can differentially affect structural brain maturation during adolescence and underlie enhanced susceptibility to impulsivity. Additional studies with larger sample sizes are warranted.

Prenatal substance abuse: short- and long-term effects on the exposed fetus

Prenatal substance abuse continues to be a significant problem in this country and poses important health risks for the developing fetus. The primary care pediatrician's role in addressing prenatal substance exposure includes prevention, identification of exposure, recognition of medical issues for the exposed newborn infant, protection of the infant, and follow-up of the exposed infant. This report will provide information for the most common drugs involved in prenatal exposure: nicotine, alcohol, marijuana, opiates, cocaine, and methamphetamine.

Profiles of Reactivity in Cocaine-Exposed Children

This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological, behavioral and maternal reported measures of reactivity. Five replicable clusters were identified which corresponded to 1) Dysregulated/High Maternal Report Reactors, 2) Low Behavioral Reactors, 3) High Reactors, 4) Optimal Reactors and 5) Dysregulated/Low Maternal Report Reactors. These clusters were associated with differences in prenatal cocaine exposure status, birthweight, maternal depressive symptoms, and maternal negative affect during mother-infant interactions. These results support the presence of distinct reactivity profiles among high risk infants recruited on the basis of prenatal cocaine exposure and demographically similar control group infants not exposed to cocaine.

Estimated effect of prenatal cocaine exposure on examiner-rated behavior at age 7 years

Prenatal cocaine exposure has been linked to increased child behavior difficulties in some studies but not others.

OBJECTIVE

The primary aim was to estimate the relationship between in utero cocaine exposure and child behavioral functioning at age 7 years with ratings made by blinded examiners during a structured testing session. A second aim was to examine whether caregiver drug use and psychological problems might mediate suspected relationships between prenatal cocaine exposure and aspects of examiner-rated behavior.

METHODS

407 children (212 cocaine-exposed, 195 non-exposed) participating in the longitudinal Miami Prenatal Cocaine Study (MPCS) were rated with regard to their behavior during a neuropsychological assessment conducted at age 7 years. Raters were trained research psychometricians blinded to drug exposure status. Individual behavioral items were summarized and the cocaine-behavior relationship was estimated within the context of latent variable modeling, using Mplus software.

RESULTS

Two latent variables, Behavioral Regulation and Sociability, were derived via exploratory latent structure analysis with promax rotation. Prenatal cocaine exposure, statistically controlling for child sex, test age, and prenatal exposure to alcohol, tobacco, and marijuana, was associated with Behavioral Regulation (estimated slope ß=-0.25; 95% CI=-0.48, -0.02; p=0.04) but not Sociability (estimated slope ß=-0.03; 95% CI=-0.26, 0.20; p=0.79). Neither postnatal drug use by caregivers nor the severity of their psychological problems at age 5 follow-up predicted levels of child Behavioral Regulation or Sociability at age 7 years (p>0.10).

CONCLUSIONS

Examiner ratings of child behavior at age 7 revealed less optimal behavioral regulation for prenatally cocaine-exposed compared to non-exposed children, in contrast with what had been previously found from parent-report data. This evidence highlights the potential value of trained observers in assessing behavioral outcomes of children exposed in utero to drugs and other toxicants.

Prenatal Cocaine Disrupts Serotonin Signaling-Dependent Behaviors: Implications for Sex Differences, Early Stress and Prenatal SSRI Exposure

Prenatal cocaine (PC) exposure negatively impacts the developing nervous system, including numerous changes in serotonergic signaling. Cocaine, a competitive antagonist of the serotonin transporter, similar to selective serotonin reuptake inhibitors (SSRIs), also blocks dopamine and norepinephrine transporters, leaving the direct mechanism through which cocaine disrupts the developing serotonin system unclear. In order to understand the role of the serotonin transporter in cocaine's effect on the serotonergic system, we compare reports concerning PC and prenatal antidepressant exposure and conclude that PC exposure affects many facets of serotonergic signaling (serotonin levels, receptors, transporters) and that these effects differ significantly from what is observed following prenatal SSRI exposure. Alterations in serotonergic signaling are dependent on timing of exposure, test regimens, and sex. Following PC exposure, behavioral disturbances are observed in attention, emotional behavior and stress response, aggression, social behavior, communication, and like changes in serotonergic signaling, these effects depend on sex, age and developmental exposure. Vulnerability to the effects of PC exposure can be mediated by several factors, including allelic variance in serotonergic signaling genes, being male (although fewer studies have investigated female offspring), and experiencing the adverse early environments that are commonly coincident with maternal drug use. Early environmental stress results in disruptions in serotonergic signaling analogous to those observed with PC exposure and these may interact to produce greater behavioral effects observed in children of drug-abusing mothers. We conclude that based on past evidence, future studies should put a greater emphasis on including females and monitoring environmental factors when studying the impact of PC exposure.

Caregiver and self-report of mental health symptoms in 9-year old children with prenatal cocaine exposure

OBJECTIVE

To assess the effect of prenatal cocaine exposure on mental health symptoms in 9-year old children controlling for potential confounders.

METHODS

332 children (170 prenatally cocaine-exposed (PCE), 162 non cocaine-exposed (NCE) were assessed using self (Dominic Interactive; DI) and caregiver report (Child Behavior Checklist; CBCL).

RESULTS

Higher levels of PCE were associated with caregiver report of clinically elevated aggressive and delinquent behavior. With each increased unit of PCE, children were 1.3 times more likely to be rated as aggressive (OR=1.30, 95% CI: 1.02-1.67, p<0.04). For each increased unit of PCE, girls were 2 times more likely to be rated as having delinquent behavior (OR=2.08, 95% CI: 1.46-2.96, p<0.0001). PCE status was also associated with increased odds of delinquent behavior (OR=2.41; 95% CI: 1.16-4.97, p=0.02), primarily due to the increased risk among girls with PCE. While girls with PCE status were 7 times more likely than NCE girls to have delinquent behaviors (OR=7.42; 95% CI: 2.03-27.11, p<0.002) boys with PCE did not demonstrate increased risk (OR=0.98; 95% CI: 0.36-2.65, p>0.97). Foster or adoptive parents were more likely to rate their PCE children as having more thought problems, inattention, delinquent behavior, aggression, externalizing and overall problems (p<0.05) than biologic mothers or relative caregivers. Higher 2nd trimester tobacco exposure was associated with increased odds of caregiver reported anxiety (OR=1.73; 95% CI 1.06-2.81, p<0.03) and marijuana exposure increased the odds of thought problems (OR=1.68; 95% CI 1.01-2.79, p<0.05). Children with PCE self-reported fewer symptoms of oppositional defiant disorder (ODD) compared to NCE children (OR=0.44, 95% CI: 0.21-0.92, p<0.03). Greater tobacco exposure was associated with increased odds of child reported ODD (OR=1.24; 95% CI 1.03-1.78, p<0.03).

CONCLUSION

Higher PCE was associated with disruptive behaviors including aggression and delinquent behavior among girls by caregiver report, but not child report. These findings highlight the need for early behavioral assessment using multiple informants in multi-risk children.

Cocaine Exposure and Children's Self-Regulation: Indirect Association via Maternal Harshness

OBJECTIVES

This study examined the association between prenatal cocaine exposure and children's self-regulation at 3 years of child age. In addition to direct effects of prenatal cocaine exposure on children's self-regulation, we hypothesized there would be indirect associations between cocaine exposure and self-regulation via higher maternal harshness and poor autonomic regulation in infancy.

METHODS

The sample consisted of 216 mother-infant dyads recruited at delivery from local area hospitals (116 cocaine-exposed, 100 non-exposed). Infant autonomic regulation was measured at 7 months of age during an anger/frustration task, maternal harshness was coded from observations of mother-toddler interactions at 2 years of age, and children's self-regulation was measured at 3 years of age using several laboratory paradigms.

RESULTS

Contrary to hypotheses, there were no direct associations between maternal cocaine use during pregnancy and children's self-regulation. However, results from testing our conceptual model including the indirect effects via maternal harshness or infant parasympathetic regulation indicated that this model fit the data well, χ(2) (23) = 34.36, p > 0.05, Comparative Fit Index = 0.95, RMSEA = 0.05. Cocaine using mothers displayed higher intensity of harshness toward their toddlers during lab interactions across a variety of tasks at 2 years of age (β = 0.23, p < 0.05), and higher intensity of harshness at 2 years was predictive of lower self-regulation at 3 years (β = -0.36, p < 0.01). Maternal cocaine use was also predictive of a non-adaptive increase in respiratory sinus arrhythmia (RSA) from baseline to the negative affect task, but RSA change in infancy was not predictive of self-regulation at 3 years.

CONCLUSION

RESULTS are supportive of animal models indicating higher aggression among cocaine treated dams, and indicate that higher maternal harshness among cocaine using mothers is predictive of child self-regulatory outcomes in the preschool period.

Maternal cocaine use and mother-infant interactions: Direct and moderated associations

This study examined the associations between prenatal cocaine exposure and quality of mother-infant play interactions at 13 months of infant ages. We investigated whether maternal psychological distress and infant reactivity mediated or moderated this association. Participants consisted of 220 (119 cocaine exposed and 101 non-cocaine exposed) mother-infant dyads participating in an ongoing longitudinal study of prenatal cocaine exposure. Results indicated that mothers who used cocaine during pregnancy displayed higher negative affect and lower sensitivity toward their infant during play interactions at 13 months, and that their infants were less responsive toward them. Contrary to hypothesis, this association was not mediated by maternal psychological distress or by infant reactivity. However, results for both the cocaine and non-cocaine exposed infants were supportive of a transactional model where lower maternal sensitivity at 1 month was predictive of higher infant reactivity at 7 months, which in turn was predictive of lower maternal warmth/sensitivity at 13 months, controlling for potential stability in maternal behavior. Results also indicated that as hypothesized, infant reactivity moderated the association between maternal cocaine use during pregnancy and maternal warmth/sensitivity at 13 months of age. Cocaine-using mothers who experienced their infants as being more reactive in early infancy were less warm/sensitive toward them in later infancy. Results have implications for parenting interventions that may be targeted toward improving maternal sensitivity among cocaine-using mothers with more reactive infants.

Development of inhibitory control among prenatally cocaine exposed and non-cocaine exposed youths from late childhood to early adolescence: The effects of gender and risk and subsequent aggressive behavior

The goal of the present investigation was to characterize the development of inhibitory control, an aspect of executive functions, in a sample of prenatally cocaine exposed (CE; n=165) children compared to an at risk, but prenatally cocaine unexposed (NCE; n=119) sample across time (i.e. 7.5 to 11.5 years of age). Gender and cumulative risk, a combination of postnatal medical (i.e. low birth weight and APGAR scores) and demographic risk, indexed by maternal educational attainment, were examined as predictors of change in inhibitory control across time and aggression was modeled as an outcome when children reached 14 years of age. Multiple group latent growth models indicated that CE children made more errors at 7.5 years of age during a standard Stroop interference task, however, over time CE children had greater age-related improvements, narrowing the initial gap, with NCE children in the ability to inhibit errors. Gender effects at 7.5 years within the NCE group were identified with NCE boys making initially more errors than NCE girls; both NCE and CE girls improved faster across development compared to NCE and CE boys, respectively. Greater cumulative risk was associated with more errors at 7.5 years in the CE and NCE groups. No differences were observed between CE and NCE children on time to complete the Stroop task at 7.5 years. However, NCE children had greater age-related improvements in their time to complete the Stroop interference task relative to their CE counterparts. NCE girls improved the fastest over time relative to NCE boys; a similar trend emerged (p<0.10) with CE girls improving faster over time than CE boys. Although all participants improved across development, higher cumulative risk in both groups was associated with slower age-related improvements (i.e. higher slopes) in the time to complete the Stroop task across development. After accounting for gender and cumulative risk, findings in both groups indicated that those who made more errors at 7.5 years of age and/or who had slower age-related changes (i.e. higher slopes) of time to complete the Stroop task across development were more aggressive as rated by caregivers at 14 years of age. Although qualified by gender and cumulative risk, these findings are consistent with reduced cognitive processing efficiency and executive function difficulties in CE children relative to NCE children. Findings suggest that executive function difficulties in CE children may be subtle as development continues to unfold over time. Furthermore, these findings indicate that development of inhibitory control may be an important mechanism linking prenatal cocaine exposure, gender, and cumulative risk to later adverse outcomes.

Increased "default mode" activity in adolescents prenatally exposed to cocaine

Prenatal cocaine exposure (PCE) is associated with attention/arousal dysregulation and possible inefficiencies in some cognitive functions. However, the neurobiological bases of these teratogenic effects have not been well characterized. Because activities in the default mode network (DMN) reflect intrinsic brain functions that are closely associated with arousal regulation and cognition, alterations in the DMN could underlie cognitive effects related to PCE. With resting-state and task activation functional magnetic resonance imaging (fMRI), this study investigated the possible PCE related changes in functional brain connectivity and brain activation in the DMN. In the resting state, the PCE group was found to have stronger functional connectivity in the DMN, as compared to the nonexposed controls. During a working memory task with emotional distracters, the PCE group exhibited less deactivation in the DMN and their fMRI signal was more increased by emotional arousal. These data revealed additional neural effects related to PCE, and consistent with previous findings, indicate that PCE may affect behavior and functioning by increasing baseline arousal and altering the excitatory/inhibitory balancing mechanisms involved in cognitive resource allocation.

Behavioral characterization of adult male and female rhesus monkeys exposed to cocaine throughout gestation

RATIONALE

In utero cocaine exposure has been associated with alterations in the dopamine (DA) system in monkeys. However, the behavioral outcomes of prenatal cocaine exposure in adulthood are poorly understood.

OBJECTIVES

To assess several behavioral measures in 14-year-old rhesus monkeys exposed to cocaine in utero and controls (n = 10 per group).

MATERIALS AND METHODS

For these studies, two unconditioned behavioral tasks, novel object reactivity and locomotor activity, and two conditioned behavioral tasks, response extinction and delay discounting, were examined. In addition, cerebrospinal fluid (CSF) samples were analyzed for concentrations of the monoamine metabolites homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA).

RESULTS

No differences in CSF concentrations of 5-HIAA and HVA, latencies to touch a novel object or locomotor activity measures were observed between groups or sexes. However, prenatally cocaine-exposed monkeys required a significantly greater number of sessions to reach criteria for extinction of food-reinforced behavior than control monkeys. On the delay-discounting task, male prenatally cocaine-exposed monkeys switched preference from the larger reinforcer to the smaller one at shorter delay values than male control monkeys; no differences were observed in females.

CONCLUSIONS

These findings suggest that prenatal cocaine exposure results in long-term neurobehavioral deficits that are influenced by sex of the individual.

The effects of prenatal cocaine exposure and gender on inhibitory control and attention

Children exposed prenatally to cocaine show deficits in emotion regulation and inhibitory control. While controlling for the measures of medical complication in the perinatal period, environmental risk, and prenatal polydrug exposure (alcohol, tobacco, and marijuana), we examined the effects of prenatal cocaine exposure and gender on attention and inhibitory control in 203 children at ages 6, 9, and 11. Cocaine exposure affected the performance of males, but not females. Heavily exposed males showed deficits in the attention and the inhibition tasks. In addition, a significantly greater proportion of heavily exposed males (21%) than unexposed males (7%) or heavily exposed females (7%) failed to complete the task (p<0.01). Even without those poorest performing subjects, the overall accuracy for heavily exposed males (81%) was significantly reduced (p<0.05) compared to lightly exposed males (87%) and unexposed males (89%). The findings highlight the importance of considering gender specificity in cocaine exposure effects. Processes by which cocaine effects may be specific to males are discussed.

Infant temperament and high-risk environment relate to behavior problems and language in toddlers

OBJECTIVE

This study examined the role that easy infant temperament and cumulative environmental risk play in predicting cognitive, language, and behavioral outcomes in 3-year-old children at high social risk.

METHODS

Subjects were 412 mother-infant dyads, recruited at birth, participating in a longitudinal study examining the effects of prenatal methamphetamine on child development. This analysis includes a subsample (n = 290) of the study with a completed 3-year visit. Temperament was assessed by the Infant Behavior Questionnaire at 12 months. Factor analysis from well-validated measures generated “easy” and “difficult” temperament profiles and a profile for high-risk environment. Caretaker receptive vocabulary served as a proxy for intelligence quotient. Outcomes at 3 years included motor and mental development, behavior problems, and language. Linear regression and hierarchical linear modeling examined the effects of temperament, high-risk environment, and caregiver receptive language on outcomes adjusting for maternal drug use and demographic and socioeconomic covariates.

RESULTS

Internalizing and externalizing behaviors were lower in children with easy temperament and higher with increased environmental risk. Easy temperament attenuated behavioral problems only in the setting of lower environmental risk. Caregiver receptive language was associated with lower internalizing scores. High-risk environment and temperament factors were not related to cognitive or motor outcomes. Prenatal methamphetamine exposure was not associated with 3-year-old outcomes, nor did it alter the protective effects of an easier temperament on child behavior.

CONCLUSIONS

CHILDREN growing up in adverse social environments had increased behavioral problems and compromised language development. Conversely, an easy temperament acts as a protective factor for social-emotional development and could be related to resilience.

Prenatal cocaine exposure, gender, and adolescent stress response: a prospective longitudinal study

Prenatal cocaine exposure is associated with alterations in arousal regulation in response to stress in young children. However, relations between cocaine exposure and stress response in adolescence have not been examined. We examined salivary cortisol, self-reported emotion, heart rate, and blood pressure (BP) responses to the Trier Social Stress Test (TSST) in 49 prenatally cocaine and other drug exposed (PCE) and 33 non-cocaine-exposed (NCE) adolescents. PCE adolescents had higher cortisol levels before and after stress exposure than NCE adolescents. PCE girls showed an elevated anxiety response to stress (compared to NCE girls) and PCE boys showed a dampened diastolic BP response (compared to NCE boys). Girls showed higher anger response and lower pre-stress systolic BP than boys. Group differences were found controlling for potential confounding variables and were not moderated by caregiver-child relationship quality (although relationship quality predicted HPA axis and anxiety response). The findings suggest that prenatal drug exposure is associated with altered stress response in adolescence and that gender moderates this association.

Prenatal cocaine exposure: Effects on mother- and teacher-rated behavior problems and growth in school-age children

In this longitudinal study of prenatal cocaine exposure (PCE), school-age physical and cognitive development and behavioral characteristics were examined, while controlling for other factors that affect child development. At this follow-up phase, children were on average 7.2 years old, and their caregivers were 33.7 years old, had 12.5 years of education, and 48% were African American. During the first trimester, 20% of the women were frequent cocaine users (≥1 line/day). First trimester cocaine exposure predicted decreased weight and height at 7 years. There was no significant relationship between PCE and the cognitive and neuropsychological measures. Third trimester cocaine use predicted more total and externalizing behavior problems on the Child Behavior Checklist (Achenbach, 1991 [3]) and the Teacher Report Form (Achenbach, 1991 [4]), and increased activity, inattention, and impulsivity on the Routh Activity (Routh et al., 1974 [67]) and SNAP scales (Pelham and Bender, 1982 [55]). Children who were exposed to cocaine throughout pregnancy had more mother- and teacher-rated behavior problems compared to children of women who stopped using early in pregnancy or who never used cocaine prenatally. These detrimental effects of PCE on behavior are consistent with other reports in the literature and with the hypothesis that PCE affects development through changes in neurotransmitter systems. These school-age behaviors may be precursors of later adolescent behavior problems.

Preadolescent behavior problems after prenatal cocaine exposure: Relationship between teacher and caretaker ratings (Maternal Lifestyle Study)

BACKGROUND

We previously reported an association between prenatal cocaine exposure (PCE) and childhood behavior problems as observed by the parent or caretaker. However, these behavior problems may not manifest in a structured environment, such as a school setting.

OBJECTIVE

We determined whether there is an association between PCE and school behavior problems and whether ratings of behavior problems from the teacher differ from those noted by the parent or caretaker.

METHODS

The Maternal Lifestyle Study, a multicenter study, enrolled 1388 children with and without PCE at one month of age for longitudinal assessment. Teachers masked to prenatal drug exposure status completed the Teacher Report Form (TRF/6-18) when children were 7, 9, and 11 years old. We also administered the Child Behavior Checklist-parent report (CBCL) to the parent/caretaker at same ages and then at 13 years. We performed latent growth curve modeling to determine whether high PCE will predict externalizing, internalizing, total behavior, and attention problems at 7 years of age and whether changes in problems' scores over time differ between those exposed and non-exposed from both teacher and parent report. Besides levels of PCE as predictors, we controlled for the following covariates, namely: site, child characteristics (gender and other prenatal drug exposures), family level influences (maternal age, depression and psychological symptomatology, continuing drug use, exposure to domestic violence, home environment, and socioeconomic status), and community level factors (neighborhood and community violence).

RESULTS

The mean behavior problem T scores from the teacher report were significantly higher than ratings by the parent or caretaker. Latent growth curve modeling revealed a significant relationship between intercepts of problem T scores from teacher and parent ratings; i.e., children that were rated poorly by teachers were also rated poorly by their parent/caretaker or vice versa. After controlling for covariates, we found high PCE to be a significant predictor of higher externalizing behavior problem T scores from both parent and teacher report at 7 years (p=0.034 and p=0.021, respectively) in comparison to non-PCE children. These differences in scores from either teacher or caregiver were stable through subsequent years or did not change significantly over time. Boys had higher T scores than girls on internalizing and total problems by caretaker report; they also had significantly higher T scores for internalizing, total, and attention problems by teacher ratings; the difference was marginally significant for externalizing behavior (p=0.070). Caretaker postnatal use of tobacco, depression, and community violence were significant predictors of all behavior problems rated by parent/caretaker, while lower scores on the home environment predicted all behavior outcomes by the teacher report.

CONCLUSIONS

Children with high PCE are likely to manifest externalizing behavior problems; their behavior problem scores at 7 years from either report of teacher or parent remained higher than scores of non-exposed children on subsequent years. Screening and identification of behavior problems at earlier ages could make possible initiation of intervention, while considering the likely effects of other confounders.

Predicting preschool effortful control from toddler temperament and parenting behavior

This longitudinal study assessed whether maternal behavior and emotional tone moderated the relationship between toddler temperament and preschooler's effortful control. Maternal behavior and emotional tone were observed during a parent-child competing demands task when children were 2 years of age. Child temperament was also assessed at 2 years of age, and three temperament groups were formed: inhibited, exuberant, and low reactive. At 4.5 years of age, children's effortful control was measured from parent-report and observational measures. Results indicated that parental behavior and emotional tone appear to be especially influential on exuberant children's effortful control development. Exuberant children whose mothers used commands and prohibitive statements with a positive emotional tone were more likely to be rated higher on parent-reported effortful control 2.5 years later. When mothers conveyed redirections and reasoning-explanations in a neutral tone, their exuberant children showed poorer effortful control at 4.5 years.

Children of addicted women

The purpose of this article was to review follow up studies of children with prenatal drug exposure from preschool through adolescence. Specifically, the authors focus on the effects of prenatal exposure to cocaine, methamphetamine, and opiates on behavior and development. The largest number of studies have examined cocaine-exposed children. The authors identified 42 studies that suggest that there are unique effects of prenatal cocaine exposure on 4- to 13-year-old children, particularly in the areas of behavior problems, attention, language, and cognition. In addition, studies make reasonable attempts to control for possible confounding factors. Systematic research on the long-term effects of prenatal methamphetamine exposure is just beginning but seems to be showing similar effects to that of cocaine. The literature on the on the long-term effects of children with prenatal opiate exposure is more substantial than the methamphetamine literature but it is still relatively sparse and surprising in that there is little recent work. Thus, there are no studies on the current concerns with opiates used for prescription mediation. There is a growing literature using neuroimaging techniques to study the effects of prenatal drug exposure that holds promise for understanding brain/behavior relationships. In addition to pharmacological and teratogenic effects, drugs can also be viewed from a prenatal stressor model. The author discuss this "fetal origins" approach that involves fetal programming and the neuroendocrine system and the potential implications for adolescent brain and behavioral development.

Problematic dyadic interaction among toddlers and their polydrug-cocaine-using mothers

Dyadic interactions between 84 at-risk toddlers and their nondrug-, polydrug-non-cocaine-, or polydrug-cocaine-using mothers were examined during unstructured play. Coded videotaped behaviors revealed two maternal constructs (interactive competence, maladaptive engagement) and three toddler constructs (responsiveness, active positive initiation, play). Cocaine-using mothers displayed more maladaptive engagement than did prenatal nondrug users; however, poorer interactive competence further distinguished them from polydrug-but-noncocaine users. Toddlers of cocaine-using mothers displayed less responsiveness and positive initiation than non-drug-group peers; however, these behaviors did not reliably differ from polydrug-non-cocaine counterparts. Play interest remained relatively similar across groups. Results suggest that difficulties in social interaction appear to continue among cocaine-using mothers during dyadic exchanges with their offspring in the second year; however, toddler deficits do not appear to be greater than those experienced by polydrug-non-cocaine counterparts.

Sex differences in the effects of cocaine abuse across the life span

Cocaine alters brain function from the early days of development throughout the entire life of an individual. Since the first preclinical research on cocaine sensitization was published, sex differences in response to the drug in adult rats have been noted. With the appearance of reports on "crack babies" during the 1980s, sex differences in response to prenatal (developmental) exposure have been identified in both clinical and preclinical reports. Cocaine administered during early development in the rat produces wide-spread alterations in function which depend on the timing of drug administration as well as the sex of the animal. In males, the response patterns following postnatal days (PND) 11-20 cocaine administration (equivalent to the late prenatal period in humans) are quite similar to those seen following prenatal exposure (equivalent to the first half of pregnancy in humans). There is a general decrease in dopaminergic (DA) markers and reactivity perhaps due to the uncoupling of the D1 receptor from its second messenger system. While similar changes in D1 uncoupling are seen in females, behavioral and metabolic responses to drug challenges generally show increases in DA responsivity (except adolescents) perhaps due to the activational effects of estrogen and/or decreases in serotonin (5-HT) mediated regulation of DA function. We have found that a significant factor in the hyper-responsivity of the female is the role of the testing environment and the responses to stress which can obscure underlying neurochemical dysregulation. Whether parallel factors are operational in adult males and females is currently under investigation.

Continued effects of prenatal cocaine use: preschool development

The relationship between prenatal cocaine use and preschooler's physical and cognitive development and behavioral characteristics was examined, controlling for other influences on child development. On average, children were 38.5 months old, women were 29.4 years old, had 12.3 years of education, and 47% were African American. During the first trimester, 18% of the women were frequent cocaine users (> or = 1 line/day). First trimester cocaine exposure predicted decreased head circumference at 3 years and lower scores on the short-term memory subscale of the Stanford-Binet Intelligence Scale (SBIS) [74]. There was no significant relationship between prenatal cocaine use and the other SBIS scales. First trimester cocaine use also predicted more total, internalizing, and externalizing behavior problems on the Child Behavior Checklist [3] and higher scores on the fussy/difficult scale of the Infant Characteristics Questionnaire [6]. Children who were exposed to cocaine throughout pregnancy had more behavior problems and were more fussy compared to children of women who never used cocaine prenatally. A repeated measures analysis showed that children of first trimester cocaine users became more fussy over time. These detrimental effects on growth and behavior are consistent with other reports in the literature and with the hypothesis that prenatal cocaine exposure affects development through changes in neurotransmitter systems.

Emotional arousal in cocaine exposed toddlers: prediction of behavior problems

Prenatal cocaine exposure (PCE) may be associated with alterations in children's developing emotional arousal and regulation systems.

OBJECTIVE

We examined emotional responses to a frustrating task and subsequent behavior problems in 225 2 1/2 year olds (129 Prenatally Cocaine and Other Drug Exposed [PCE], 30 Non Cocaine but other drug Exposed [NCE], 66 Non Drug Exposed [NDE]).

METHOD

Children's behaviors in a frustrating toy wait task at age 2 1/2 were coded for emotional arousal and regulation behaviors.

RESULTS

Findings indicated a trend for PCE toddlers to show greater agitated emotional arousal than NCE and NDE toddlers. Further, PCE boys made more references to their caregivers in the task than NDE boys. Higher agitated arousal at age 2 1/2 years was related to greater decreases in externalizing behaviors through age 5 1/2 years.

CONCLUSION

Findings suggest a link between cocaine exposure and emotional arousal and regulation and highlight the need to understand complex relations between emotion and risk for later psychopathology in exposed youth.

Prenatal cocaine exposure alters emotional arousal regulation and its effects on working memory

While prenatal cocaine exposure (PCE) has been associated with arousal dysregulation and attentional impairments in both human and animal studies, the neurobiological bases of these teratogenic effects have not been well characterized. In the current study, we report functional neuroimaging observations of these effects in exposed youth. Using functional magnetic resonance imaging (fMRI), we embedded task-irrelevant emotional distracters in a working memory task to examine the interaction of emotional arousal and memory in 33 PCE and 23 non-exposed adolescents. Though with similar behavioral performance, the two groups exhibited different activation patterns associated with emotion-memory interactions. On the one hand, higher memory load attenuated emotion-related amygdala activation in controls but not in the exposed adolescents; on the other hand, prefrontal activation associated with memory load decreased in the presence of emotional distraction in the controls but increased in the exposed group. These group interaction differences suggest neurobiological substrates for arousal-associated neuronal alterations related to prenatal cocaine exposure. Consistent with previous findings in behavioral and physiological studies, the present neuroimaging data provided more in-depth evidence supporting the view that PCE has significant long-term teratogenic effect on arousal regulation system.

Executive functioning at ages 5 and 7 years in children with prenatal cocaine exposure

This prospective longitudinal study evaluated the effect of prenatal cocaine exposure (PCE) on executive functioning in 5- and 7-year-old children. In total, 154 pregnant cocaine users, identified by urine toxicology and structured interviews, were matched to 154 nonusers. Children were assessed by certified masked evaluators, and caregivers were interviewed by experienced staff during home visits. In approximately 90% of the surviving sample tested at ages 5 and 7 years, structural equation modeling demonstrated that an increased head circumference at birth (adjusted for gestation) significantly predicted better performance on executive functioning, and that PCE was indirectly related to executive functioning through its significant negative effect on head circumference at birth. At age 5 years, quality of environment also predicted executive functioning, and the R(2) for the total model was 0.24. At 7 years, caregiver functioning predicted quality of environment, which in turn was positively related to executive functioning, and girls had better executive functioning. The total model at age 7 years accounted for 30% of the variance in executive functioning.

Prenatal cocaine exposure and infant cortisol reactivity

This study examined the effects of prenatal cocaine exposure on infant hypothalamic-pituitary-adrenal axis activity and reactivity at 7 months of infant age. Participants were 168 caregiver-infant dyads (87 cocaine exposed, 81 not cocaine exposed; 47% boys). Maternal behavior, caregiving instability, and infant growth and behavior were assessed, and children's saliva was sampled before, during, and after standardized procedures designed to elicit emotional arousal. Results revealed cocaine-exposed infants had a high amplitude trajectory of cortisol reactivity compared to non-cocaine-exposed infants. Infant gender and caregiving instability moderated this association. The findings support a dual hazard vulnerability model and have implications for evolutionary-developmental theories of individual differences in biological sensitivity to context.

Effects of prenatal cocaine exposure on infant reactivity and regulation

The purpose of this study was to examine the role of prenatal cocaine exposure and associated risk factors on infant reactivity and regulation at 7 months of infant age. Participants consisted of 167 mother-infant dyads participating in an ongoing longitudinal study of prenatal cocaine exposure, who completed the arm restraint procedure at the 7-month assessment (87 cocaine exposed, 80 non-cocaine exposed). We hypothesized that cocaine exposed infants would display higher arousal or reactivity and lower regulation during a procedure designed to arouse anger/frustration. Results indicated that cocaine exposed infants were more reactive to increases in the level of stress from trial 1 to trial 2 but exhibited no change in the number of regulatory strategies as stress increased, unlike the control group infants. Infant birth weight moderated the association between cocaine exposure and infant regulation. Among cocaine exposed infants, those with lower birth weight displayed higher reactivity compared to those with higher birth weight. Contrary to expectations, there were no indirect effects between cocaine exposure and infant reactivity/regulation via environmental risk, parenting, or birth weight. Results are supportive of a teratological model of prenatal cocaine exposure for infant reactivity/regulation in infancy.

Children's cognitive ability from 4 to 9 years old as a function of prenatal cocaine exposure, environmental risk, and maternal verbal intelligence

This study examined the effects of prenatal cocaine exposure, environmental risk, and maternal verbal intelligence on children's cognitive ability. Gender and age were examined as moderators of potential cocaine exposure effects. The Stanford-Binet IV intelligence test was administered to 231 children (91 cocaine exposed, 140 unexposed) at ages 4, 6, and 9 years. Neonatal medical risk and other prenatal exposures (alcohol, cigarettes, and marijuana) were also examined for their unique effects on child IQ. Mixed models analysis indicated that prenatal cocaine exposure interacted with gender, as cocaine-exposed boys had lower composite IQ scores. Age at assessment did not moderate this relation, indicating that cocaine-exposed boys had lower IQs across this age period. A stimulating home environment and high maternal verbal IQ also predicted higher composite IQ scores. Cocaine-exposed boys had lower scores on the Abstract/Visual Reasoning subscale, with trends for lower scores on the Short-Term Memory and Verbal Reasoning subscales, as exposure effects were observed across domains. The findings indicate that cocaine exposure continues to place children at risk for mild cognitive deficits into preadolescence. Possible mechanisms for the Exposure x Gender interaction are discussed.

A systematic review of challenging behaviors in children exposed prenatally to substances of abuse

A review of the existing literature on the occurrence of challenging behavior among children with prenatal drug exposure was conducted. While a large number of studies were identified that evaluated various outcomes of prenatal drug exposure, only 37 were found that directly evaluated challenging behaviors. Of the 37 studies, 23 focused on prenatal cocaine exposure, and 14 focused on prenatal alcohol exposure; most studies relied on broadband measures such as the CBCL for the assessment of challenging behavior. Among the 37 studies, a clear role for the postnatal environment on developing challenging behaviors was evident; however, prenatal alcohol exposure showed a much clearer independent effect upon challenging behaviors than was noted in the prenatal cocaine studies. Additionally, only 3 of the 37 studies addressed interventions for challenging behaviors, each of which showed an improvement in child behavior or parent-child interactions. As researchers have continued to show the importance of the postnatal environment, it is likely that interventions addressing specific environmental risk factors will be helpful to reduce or prevent challenging behaviors among this population.

Children's cognitive-behavioral functioning at age 6 and 7: prenatal drug exposure and caregiving environment

OBJECTIVE

The aim of this study was to examine how prenatal drug exposure (PDE) and caregiving environment relate to cognitive, academic, and behavioral performance at ages 6 and 7.

METHODS

A longitudinal follow-up was conducted of 111 children with PDE and a community cohort of 62 non-drug-exposed children (N = 173). Children completed standardized tests of cognition (Stanford-Binet Intelligence Scales, Fourth Edition [SB-IV]) and academic performance (Wide Range Achievement Test 3). Caregivers completed ratings of child behavior problems (Child Behavior Checklist [CBCL]). Multivariate analyses were conducted, adjusting for gender, prenatal tobacco exposure, number of caregiver placement changes, and 3 caregiver variables assessed at age 7, including depressive symptoms, employment status, and public assistance status.

RESULTS

After adjusting for perinatal and environmental variables, there were no significant exposure-group differences in cognition, academic performance, or behavior problems. In comparison with males, females had higher scores on overall IQ and 4 of 8 SB-IV subtests, fewer caregiver-reported attention and aggression problems, and higher reading achievement scores. There were no significant gender-by-group interactions.

CONCLUSION

When analyses were adjusted for perinatal and environmental variables, most associations between PDE and cognitive-behavioral functioning were attenuated. Regardless of drug exposure history, males performed more poorly than females on multiple cognitive-behavioral indices. Both exposed and nonexposed children were from low-income families and obtained scores substantially below normative expectations.

Preadolescent health risk behavior as a function of prenatal cocaine exposure and gender

OBJECTIVE

To examine the effect of prenatal cocaine exposure on health risk behaviors during preadolescence.

METHODS

The present study examined prenatal cocaine exposure, gender, and environmental risk as predictors of self-reported substance use, aggression, and a disregard for safety precautions on the Youth Risk Behavior Survey in a sample of 10.5 year olds (n = 154, including 60 who were prenatally exposed to cocaine).

RESULTS

Gender tended to moderate the effects of prenatal cocaine exposure because exposure effects were found for boys but not girls. Boys who were prenatally exposed to cocaine reported engaging in more high-risk behavior. In examining individual outcomes, cocaine exposed boys had the highest scores for aggression, substance use, and a disregard for safety precautions, although these differences were significant only for the composite health risk behavior measure.

CONCLUSIONS

The findings extend earlier work showing that prenatal cocaine exposure places boys at risk for problems of inhibitory control, emotional regulation, and antisocial behavior. Research is needed to examine whether the effects of prenatal cocaine on health risk behaviors persist into adolescence, when such behaviors tend to increase.