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

Associations between Prenatal and Postnatal Exposure to Cannabis with Cognition and Behavior at Age 5 Years: The Healthy Start Study

BACKGROUND

Prenatal exposure to cannabis may influence childhood cognition and behavior, but the epidemiologic evidence is mixed. Even less is known about the potential impact of secondhand exposure to cannabis during early childhood.

OBJECTIVE

This study sought to assess whether prenatal and/or postnatal exposure to cannabis was associated with childhood cognition and behavior.

STUDY DESIGN

This sub-study included a convenience sample of 81 mother-child pairs from a Colorado-based cohort. Seven common cannabinoids (including delta 9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD)) and their metabolites were measured in maternal urine collected mid-gestation and child urine collected at age 5 years. Prenatal and postnatal exposure to cannabis was dichotomized as exposed (detection of any cannabinoid) and not exposed. Generalized linear models examined the associations between prenatal or postnatal exposure to cannabis with the NIH Toolbox and Child Behavior Checklist T-scores at age 5 years.

RESULTS

In this study, 7% (n = 6) of the children had prenatal exposure to cannabis and 12% (n = 10) had postnatal exposure to cannabis, with two children experiencing this exposure at both time points. The most common cannabinoid detected in pregnancy was Δ9-THC, whereas the most common cannabinoid detected in childhood was CBD. Postnatal exposure to cannabis was associated with more aggressive behavior (β: 3.2; 95% CI: 0.5, 5.9), attention deficit/hyperactivity problems (β: 8.0; 95% CI: 2.2, 13.7), and oppositional/defiant behaviors (β: 3.2; 95% CI: 0.2, 6.3), as well as less cognitive flexibility (β: -15.6; 95% CI: -30.0, -1.2) and weaker receptive language (β: -9.7; 95% CI: -19.2, -0.3). By contrast, prenatal exposure to cannabis was associated with fewer internalizing behaviors (mean difference: -10.2; 95% CI: -20.3, -0.2) and fewer somatic complaints (mean difference: -5.2, 95% CI: -9.8, -0.6).

CONCLUSIONS

Our study suggests that postnatal exposure to cannabis is associated with more behavioral and cognitive problems among 5-year-old children, independent of prenatal and postnatal exposure to tobacco. The potential risks of cannabis use (including smoking and vaping) during pregnancy and around young children should be more widely communicated to parents.

Cognitive and functional outcomes at age 21 after prenatal cocaine/polydrug exposure and foster/adoptive care

OBJECTIVE

Prenatal cocaine exposure (PCE) has been linked to specific cognitive deficits and behavioral outcomes through early adolescence but there is little information on adult outcomes nor on the relationship of environmental interventions, such as foster/adoptive care, to outcomes.

METHODS

At 21 years, data were available on 325 young adults, [163 PCE and 162 non-exposed (NCE)], primarily African-American, with low SES, who were followed from birth in a prospective longitudinal cohort study. Participants were administered the Wechsler Abbreviated Scale of Intelligence (WASI-II) and surveyed regarding high school completion, problematic substance use, and incarceration/probation history. In the PCE group, 32 remained in non-kinship foster/adoptive care (PCE/FA) from early in life (< 4 years) to 17 years. Group differences were examined through t-tests, MANOVA/ MANCOVA with post-hoc analyses, comparing outcomes and environmental correlates of young adults with PCE vs. NCE, as well as outcomes of PCE young adults in non-kinship foster/adoptive care (PCE/ FA) vs. PCE in birth/kinship care and NCE young adults.

RESULTS

At 21 years, young adults with PCE had lower mean Full Scale (83.7 ± 10.4 vs. 87.3 ± 12.5, p < .01) and Perceptual Reasoning IQs (87.3 ± 11.5 vs. 91.4 ± 13.9, (p < .02), lower high school completion rates (75% vs. 86%, p < .02), and were marginally more likely to have been on probation than NCE young adults, but did not differ in Verbal IQ, self-report of problematic substance use or incarceration. Young adults with PCE in F/A had similar lower IQ scores but had better verbal skills and high school graduation rates that did not differ from NCE young adults (80.6 vs 86.2%, p > .05). They had higher drug exposure at birth and more experiences of maltreatment (p's < 0.05) but their home environment quality was better and lead levels lower (p's < 0.05) than those of young adults with PCE in birth/kinship care.

CONCLUSIONS

Young adults with PCE had lower Perceptual Reasoning and Full-Scale IQ scores, independent of caregiving placement, compared to non-exposed young adults. Young adults with PCE placed in non-kinship foster/adoptive care had lower lead levels, more stimulating home environments, better vocabulary skills and were more likely to graduate from high school than those in birth/kinship care,but were not different in their self-report of problematic substance use, or experiences of incarceration or probation. Our data suggest that some cognitive deficits observed in young adults with PCE may be biologically based, but that some functional outcomes can be modified through environmental interventions. Our data also reflect the complexity of disentangling the effects of teratologic exposures on long term outcomes across a variety of domains and the need for studies of children in the foster care system.

Co-occurrence of Psychopathology Problems in At-Risk Adolescents

No known studies have investigated co-occurrence of psychopathology problems in adolescents with biologic and/or environmental susceptibility, including prenatal drug exposure. This study identified comorbidity patterns of psychopathology problems by utilizing data from urban, primarily African American, youth, majority of whom were at heightened risk for exposure to drugs in utero. The roles of Research Domain Criteria (RDoC)-informed behavioral constructs of the Negative Valence (irritability) and Social Process Systems (social disinhibition) as antecedents of the comorbidity patterns were further examined. Lastly, the predictive validity of the identified patterns was evaluated in relation to emerging adulthood outcomes. Participants were 358 urban adolescents, primarily African Americans, drawn from a 21-year prospective birth-cohort study of the effects of prenatal drug exposure. Psychopathology problems were assessed at age 15. Irritability and social disinhibition were self-reported at age 12. Emerging adulthood outcomes were measured at age 21. Latent class modeling indicated four patterns: Normative (57%), substance-use (SU; 24%), mental-health-problems-without-substance-use (MH; 11%), and substance-use-and-other-mental-health-problems (SUMH; 7%). Higher irritability increased the odds of developing the MH pattern, whereas higher social disinhibition increased the odds of developing the SU pattern. The odds of manifesting the SUMH pattern were higher for children with higher irritability. For children with higher social disinhibition, the odds of manifesting the SUMH pattern were higher at a trend level. Adolescent comorbidity patterns were differentially associated with problematic tobacco and marijuana use and clinically relevant mental health problems in emerging adulthood, and completion of high school education. Peri-pubertal identification of individual differences in irritability and social disinhibition may mitigate the emergence of adolescent psychopathology, which could influence emerging adulthood adjustment in this at-risk population.

Associations of gestational age with gyrification and neurocognition in healthy adults

Epidemiological studies have shown that gestational age and birth weight are linked to cognitive performance in adults. On a neurobiological level, this effect is hypothesized to be related to cortical gyrification, which is determined primarily during fetal development. The relationships between gestational age, gyrification and specific cognitive abilities in adults are still poorly understood. In 542 healthy participants, gyrification indices were calculated from structural magnetic resonance imaging T1 data at 3 T using CAT12. After applying a battery of neuropsychological tests, neuropsychological factors were extracted with a factor analysis. We conducted regressions to test associations between gyrification and gestational age as well as birth weight. Moderation analyses explored the relationships between gestational age, gyrification and neuropsychological factors. Gestational age is significantly positively associated with cortical folding in the left supramarginal, bilaterally in the superior frontal and the lingual cortex. We extracted two neuropsychological factors that describe language abilities and working memory/attention. The association between gyrification in the left superior frontal gyrus and working memory/attention was moderated by gestational age. Further, the association between gyrification in the left supramarginal cortex and both, working memory/attention as well as language, were moderated by gestational age. Gyrification is associated with gestational age and related to specific neuropsychological outcomes in healthy adulthood. Implications from these findings for the cortical neurodevelopment of cognitive domains and mental health are discussed.

Self-Recognition and Emotional Knowledge

Self-recognition emerges during the second year of life and represents the emergence of a reflective self, a metacognition which underlies self-conscious emotions such as embarrassment and shame, perspective taking, and emotional knowledge of others. In a longitudinal study of 171 children, two major questions were explored from an extant database: 1) Do early factors, including IQ, general environmental risk, mother-child attachment interaction, drug exposure, gender, and neonatal risk, relate to self-recognition?; 2) Does self-recognition, along with these earlier factors, predict the child's subsequent emotional knowledge? Consistent with previous data, 39% of children exhibited self-recognition by 18-months and few early factors explored were related to this ability. Moreover, path analysis revealed few effects of the earlier factors predicting self-recognition on children's emotional knowledge. Self-recognition did predict emotional knowledge at 4.5 years, such that children who showed early self-recognition showed greater emotional knowledge. Children from high risk environments also showed lower emotional knowledge. These findings indicate that self-recognition and environmental risk are related to children's later knowledge of emotions.

Prenatal drug exposure and executive function in early adolescence

PURPOSE

Study of the relationship between prenatal cocaine exposure (PCE) and executive function (EF) has yielded inconsistent results. The purpose of the current study is to examine whether PCE, biological sex, environmental risk, and their interaction predicted EF in early adolescence.

METHODS

135 12-year-old adolescents (40.7% with PCE), who were followed prospectively from birth, attempted up to 8 Tower of Hanoi (ToH) puzzle trials of increasing complexity. The number of correctly completed puzzles served as the main outcome measure. Survival analysis was used to examine predictors of the number of successfully completed trials.

RESULTS

As trial difficulty increased, fewer adolescents were able to solve the TOH puzzle. Adolescents from high risk environments and with either prenatal alcohol or prenatal cannabis exposure completed fewer puzzles (p < .05). In addition, a hypothesized 3-way interaction of PCE x sex x environmental risk was found such that cocaine-exposed males with high environmental risk had the worst performance (p < .01).

CONCLUSIONS

The current findings are consistent with prior research indicating that males with PCE may be at particular risk of poorer functioning and highlight the potential importance of examining adolescent's sex and environmental risk as moderators of PCE effects.

A Meta-Analysis of Stressors from the Total Environment Associated with Children's General Cognitive Ability

General cognitive ability, often referred to as ‘general intelligence’, comprises a variety of correlated abilities. Childhood general cognitive ability is a well-studied area of research and can be used to predict social outcomes and perceived success. Early life stage (e.g., prenatal, postnatal, toddler) exposures to stressors (i.e., chemical and non-chemical stressors from the total (built, natural, social) environment) can impact the development of childhood cognitive ability. Building from our systematic scoping review (Ruiz et al., 2016), we conducted a meta-analysis to evaluate more than 100 stressors related to cognitive development. Our meta-analysis identified 23 stressors with a significant increase in their likelihood to influence childhood cognitive ability by 10% or more, and 80 stressors were observed to have a statistically significant effect on cognitive ability. Stressors most impactful to cognition during the prenatal period were related to maternal health and the mother’s ability to access information relevant to a healthy pregnancy (e.g., diet, lifestyle). Stressors most impactful to cognition during the early childhood period were dietary nutrients (infancy), quality of social interaction (toddler), and exposure to toxic substances (throughout early childhood). In conducting this analysis, we examined the relative impact of real-world exposures on cognitive development to attempt to understand the inter-relationships between exposures to both chemical and non-chemical stressors and early developmental life stages. Our findings suggest that the stressors observed to be the most influential to childhood cognitive ability are not permanent and can be broadly categorized as activities/behaviors which can be modified to improve childhood cognition. This meta-analysis supports the idea that there are complex relationships between a child’s total environment and early cognitive development.

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.

Totality of the Evidence Suggests Prenatal Cannabis Exposure Does Not Lead to Cognitive Impairments: A Systematic and Critical Review

Background: Despite limited data demonstrating pronounced negative effects of prenatal cannabis exposure, popular opinion and public policies still reflect the belief that cannabis is fetotoxic.

Methods: This article provides a critical review of results from longitudinal studies examining the impact of prenatal cannabis exposure on multiple domains of cognitive functioning in individuals aged 0 to 22 years. A literature search was conducted through PsycINFO, PubMed, and Google Scholar. Articles were included if they examined the cognitive performance of offspring exposed to cannabis in utero.

Results: An examination of the total number of statistical comparisons (n = 1,001) between groups of participants that were exposed to cannabis prenatally and non-exposed controls revealed that those exposed performed differently on a minority of cognitive outcomes (worse on <3.5 percent and better in <1 percent). The clinical significance of these findings appears to be limited because cognitive performance scores of cannabis-exposed groups overwhelmingly fell within the normal range when compared against normative data adjusted for age and education.

Conclusions: The current evidence does not suggest that prenatal cannabis exposure alone is associated with clinically significant cognitive functioning impairments.

Effects of prenatal marijuana exposure on neuropsychological outcomes in children aged 1-11 years: A systematic review

BACKGROUND

Normalisation of medicinal and recreational marijuana use has increased the importance of fully understanding effects of marijuana use on individual-and population-level health, including prenatal exposure effects on child development. We undertook a systematic review of the literature to examine the long-term effects of prenatal marijuana exposure on neuropsychological function in children aged 1-11 years.

METHODS

Primary research publications were searched from Medline, Embase, PsychInfo, CINAHL EbscoHost, Cochrane Library, Global Health and ERIC (1980-2018). Eligible articles documented neuropsychological outcomes in children 1-11 years who had been prenatally exposed to marijuana. Studies of exposure to multiple prenatal drugs were included if results for marijuana exposure were reported separately from other substances. Data abstraction was independently performed by two reviewers using a standardised protocol.

RESULTS

The eligible articles (n = 21) on data from seven independent longitudinal studies had high quality based on the Newcastle-Ottawa Scale. Some analyses found associations (P < 0.05) between prenatal marijuana exposure and decreased performance on memory, impulse control, problem-solving, quantitative reasoning, verbal development and visual analysis tests; as well as increased performance on attention and global motion perception tests. Limitations included concurrent use of other substances among study participants, potential under-reporting and publication biases, non-generalisable samples and limited published results preventing direct comparison of analyses.

CONCLUSIONS

The specific effects of prenatal marijuana exposure remain unclear and warrant further research. The larger number of neuropsychological domains that exhibit decreased versus increased psychological and behavioural functions suggests that exposure to marijuana may be harmful for brain development and function.

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.

Psychological Functioning of Women Taking Illicit Drugs during Pregnancy and the Growth and Development of Their Offspring in Early Childhood

OBJECTIVE

The aim of this research was to assess psychosocial history and psychological functioning in women who use drugs during pregnancy and determine how drug exposure affects child development.

METHODS

Pregnant women using marijuana (n = 38) and cocaine (n = 35) and receiving methadone maintenance (n = 24), along with a control (n = 49) group of pregnant women, were enrolled and followed every six months through 18-24 months postnatally.

RESULTS

There was a significantly higher incidence of mental illness among mothers in the drug-using groups. Prenatal stress and late-term drug severity scores were significantly higher in the mothers who used cocaine and methadone, who were also more likely to have abuse and incarceration histories. At 12 months, there were significantly higher rates of drug use in the marijuana group. Anxiety scores were highest in the methadone group. At 18 to 24 months, the methadone group reported significantly more stress, and methadone and marijuana groups had significantly higher anxiety and depression scores. At birth, neonates from the methadone and marijuana groups had significantly smaller head circumferences, with the smallest values in the methadone group. At one year, children in the cocaine group had significantly lower Bayley Scales of Infant Development-Third Edition (Bayley-III) cognitive and motor scores. At 18 to 24 months, children in the methadone group had significantly smaller head circumferences and Bayley-III cognitive scores. Children in the methadone and cocaine groups had a significantly higher incidence of atypical neurological examinations at 6 to 9 and 18 to 24 months.

CONCLUSIONS

Mothers in the methadone and cocaine groups presented with more severe prenatal drug use and psychosocial risk factors relative to women who used primarily marijuana. Children in the cocaine and methadone groups were neurologically atypical relative to others at study end. Mothers in the marijuana group reported chronic drug use as well as anxiety and depression at follow-up. At birth, children in the marijuana group were smaller, but this resolved with time. Similarly, children in the cocaine group had motor and cognitive delays that resolved by age two. Children in the methadone group had persistent growth and cognitive deficits. Their mothers demonstrated more anxiety, depression, and stress, the combination of which left these women and children liable to face ongoing psychosocial struggle and psychological distress. Dual interventions for mother and child should be considered in attempting to optimize outcome.

Evolutionary perspective on sex differences in the expression of neurological diseases

Sex-specific brain and cognitive deficits emerge with malnutrition, some infectious and neurodegenerative diseases, and often with prenatal or postnatal toxin exposure. These deficits are described in disparate literatures and are generally not linked to one another. Sexual selection may provide a unifying framework that integrates our understanding of these deficits and provides direction for future studies of sex-specific vulnerabilities. Sexually selected traits are those that have evolved to facilitate competition for reproductive resources or that influence mate choices, and are often larger and more complex than other traits. Critically, malnutrition, disease, chronic social stress, and exposure to man-made toxins compromise the development and expression of sexually selected traits more strongly than that of other traits. The fundamental mechanism underlying vulnerability might be the efficiency of mitochondrial energy capture and control of oxidative stress that in turn links these traits to current advances in neuroenergetics, stress endocrinology, and toxicology. The key idea is that the elaboration of these cognitive abilities, with more underlying gray matter or more extensive inter-modular white matter connections, makes them particularly sensitive to disruptions in mitochondrial functioning and oxidative stress. A framework of human sexually selected cognitive abilities and underlying brain systems is proposed and used to organize what is currently known about sex-specific vulnerabilities.

The association of prenatal cocaine exposure, externalizing behavior and adolescent substance use

Prenatal cocaine exposure (PCE) may increase adolescent substance use through alterations of neurotransmitter systems affecting fetal brain development. The relationship between PCE and substance use at 15 and 17 years was examined. Subjects (365: 186 PCE; 179 non-cocaine exposed (NCE)) supplied biologic and self-report data using the Youth Risk Behavior Surveillance System (YRBSS) and Computerized Diagnostic Interview Schedule for Children (C-DISC 4) at ages 15 and 17. The relationship between PCE and substance use was assessed using General Estimating Equation (GEE) analyses controlling for confounding factors including violence exposure and preschool lead level. Teens with PCE vs. NCE teens were 2 times more likely to use tobacco (OR=2.1; 95% CI 1.21-3.63; p<.001) and marijuana (OR=1.85; CI 1.18-2.91; p<.001) and have a substance use disorder at age 17 (OR=2.51; CI 1.00-6.28; p<.05). Evaluation of PCE status by gender revealed an association between PCE and marijuana use that was more pronounced for boys than girls at 17 years. Violence exposure was also a significant predictor of alcohol (p<.001), tobacco (p<.05), and marijuana (p<.0006) use and substance abuse/dependence (p<.01). Externalizing behavior at age 12 fully mediated the effects of PCE on substance use disorder at age 17 and partially mediated effects of PCE on tobacco use, but did not mediate effects on marijuana use. The percentage of substance use reported increased between 15 and 17 years, with no differences between the PCE and NCE groups. Data suggest specialized drug use prevention measures for children with PCE may benefit this high risk group.

Evolution of Sex Differences in Trait- and Age-Specific Vulnerabilities

Traits that facilitate competition for reproductive resources or that influence mate choice generally have a heightened sensitivity to stressors. They have evolved to signal resilience to infectious disease and nutritional and social stressors, and they are compromised by exposure to man-made toxins. Although these traits can differ from one species or sex to the next, an understanding of the dynamics of competition and choice can in theory be used to generate a priori predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species. I provide a review of these dynamics and illustrate associated vulnerabilities in nonhuman species. The age- and sex-specific vulnerability of such traits is then illustrated for stressor-related disruptions of boys’ and girls’ physical growth and play behavior, as well as for aspects of boys’ and girls’ and men’s and women’s personality, language, and spatial abilities. There is much that remains to be determined, but enough is now known to reframe trait sensitivity in ways that will allow scientists and practitioners to better identify and understand vulnerable human traits, and eventually ameliorate or prevent their expression.

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.

Psychological Distress Among School-Aged Children with and Without Intrauterine Cocaine Exposure: Perinatal Versus Contextual Effects

Whether intrauterine cocaine exposure (IUCE) explains unique variance in psychiatric functioning among school age children, even after controlling for other biological and social risk factors, has not been fully delineated. As part of a longitudinal birth cohort study of children with and without IUCE, we conducted and analyzed data based on structured clinical interviews with 105 children (57% male) and their caregivers when the child was approximately 8.5 years old; 47% of the children had experienced IUCE. Interviews included past and current major psychological disorders and sub-threshold mental health symptoms. Potential covariates were ascertained by interviews of birth mothers and other caregivers from shortly after the child's birth until the 8.5-year visit. More than one-third of children met DSM-IV criteria for one or more mood, anxiety, attention deficit, or disruptive behavior disorders. IUCE was not significantly associated with children's history of psychological distress, in either bivariate or multiple logistic regressions. In contrast, birth mothers' acknowledgement of greater psychiatric distress at baseline and higher levels of alcohol consumption during pregnancy, and at 8.5 years caregivers' reports of their own psychological distress, and children's lower IQ were predictors of higher rates of psychological morbidity. Findings are consistent with prior reports suggesting that, regardless of IUCE status, children from low-income, urban backgrounds are at heightened risk for psychological distress. Results underscore the need for closer monitoring of the mental health of children living in low-income households, with or without intrauterine substance exposures, to facilitate access to appropriate services.

Contributions of a Child's Built, Natural, and Social Environments to Their General Cognitive Ability: A Systematic Scoping Review

The etiology of a child’s cognitive ability is complex, with research suggesting that it is not attributed to a single determinant or even a defined period of exposure. Rather, cognitive development is the product of cumulative interactions with the environment, both negative and positive, over the life course. The aim of this systematic scoping review was to collate evidence associated with children’s cognitive health, including inherent factors as well as chemical and non-chemical stressors from the built, natural, and social environments. Three databases were used to identify recent epidemiological studies (2003–2013) that examined exposure factors associated with general cognitive ability in children. Over 100 factors were evaluated from 258 eligible studies. We found that recent literature mainly assessed the hypothesized negative effects of either inherent factors or chemical exposures present in the physical environment. Prenatal growth, sleep health, lead and water pollutants showed consistent negative effects. Of the few studies that examined social stressors, results consistently showed cognitive development to be influenced by both positive and negative social interactions at home, in school or the community. Among behavioral factors related to diet and lifestyle choices of the mother, breastfeeding was the most studied, showing consistent positive associations with cognitive ability. There were mostly inconsistent results for both chemical and non-chemical stressors. The majority of studies utilized traditional exposure assessments, evaluating chemical and non-chemical stressors separately. Collective evidence from a limited number of studies revealed that cumulative exposure assessment that incorporates multiple chemical and non-chemical stressors over the life course may unravel the variability in effect on cognitive development and help explain the inconsistencies across studies. Future research examining the interactions of multiple stressors within a child’s total environment, depicting a more real-world exposure, will aid in understanding the cumulative effects associated with a child’s ability to learn.

Prenatal cocaine exposure and child outcomes: a conference report based on a prospective study from Cleveland

OBJECTIVE

The study aims to describe developmental outcomes from a longitudinal prospective cohort (Cleveland study) of prenatally cocaine-exposed (CE) infants.

METHODS

Two hundred eighteen CE and 197 nonexposed infants were enrolled at birth and followed through mid-adolescence. Birth CE status was determined by interview and biologic measures. Multiple demographic, drug, and environmental correlates were controlled. Standardized, normative, reliable measures of fetal growth, intelligence quotient (IQ), behavior, executive function, and language were given at each age and risk for substance misuse assessed in adolescence. A subset of children received volumetric magnetic resonance imaging (MRI) at 7 years and functional MRI at 14 years. The effect of CE was determined through multiple regression analyses controlling for confounders.

RESULTS

Cocaine exposed had significant negative effects on fetal growth, attention, executive function, language, and behavior, while overall IQ was not affected. CE had significant negative effects on perceptual reasoning IQ and visual-motor skills and predicted lower volume of corpus callosum and decreased gray matter in the occipital and parietal lobes. CE children had higher risk for substance misuse. Confounding risk factors had additive effects on developmental outcomes.

CONCLUSIONS

Prenatal exposure to cocaine was related to poorer perceptual organization IQ, visual-spatial information processing, attention, language, executive function, and behavior regulation through early adolescence.

Mothers' and Fathers' Sensitivity and Children's Cognitive Development in Low-Income, Rural Families

This study examines associations between maternal and paternal sensitive parenting and child cognitive development across the first 3 years of life using longitudinal data from 630 families with co-residing biological mothers and fathers. Sensitive parenting was measured by observational coding of parent-child interactions and child cognitive development was assessed with the Bayley Scales of Infant Development and the Wechsler Preschool and Primary Scales of Intelligence. There were multiple direct and indirect associations between parenting and cognitive development across mothers and fathers, suggesting primary effects, carry-forward effects, spillover effects across parents, and transactional effects across parents and children. Associations between parenting and cognitive development were statistically consistent across mothers and fathers, and the cumulative effects of early parenting on later cognitive development were comparable to the effects of later parenting on later cognitive development. As interpreted through a family systems framework, findings suggest additive and interdependent effects across parents and children.

Effects of prenatal cocaine exposure on pubertal development

The purpose of the current study was to examine the relationship between prenatal cocaine exposure (PCE) and pubertal development. Children (n=192; 41% with PCE) completed the Pubertal Development Scale (Petersen et al. 1988) and provided salivary dehydroepiandrosterone (DHEA) samples at 6month intervals from 11 to 13years. PCE was examined as a predictor of pubertal status, pubertal tempo, and DHEA levels in mixed models analyses controlling for age, sex, environmental risk, neonatal medical problems, other prenatal exposures, and BMI. PCE interacted with age such that PCE predicted slower pubertal tempo during early adolescence. PCE also interacted with age to predict slower increases in DHEA levels during early adolescence. These findings suggest that PCE may affect pubertal development and, if slower pubertal tempo continues, could lead to delayed pubertal status in mid-adolescence.

Level of intrauterine cocaine exposure and neuropsychological test scores in preadolescence: subtle effects on auditory attention and narrative memory

Neuropsychological processes such as attention and memory contribute to children's higher-level cognitive and language functioning and predict academic achievement. The goal of this analysis was to evaluate whether level of intrauterine cocaine exposure (IUCE) alters multiple aspects of preadolescents' neuropsychological functioning assessed using a single age-referenced instrument, the NEPSY: A Developmental Neuropsychological Assessment (NEPSY) (Korkman et al., 1998), after controlling for relevant covariates. Participants included 137 term 9.5-year-old children from low-income urban backgrounds (51% male, 90% African American/Caribbean) from an ongoing prospective longitudinal study. Level of IUCE was assessed in the newborn period using infant meconium and maternal report. 52% of the children had IUCE (65% with lighter IUCE, and 35% with heavier IUCE), and 48% were unexposed. Infants with Fetal Alcohol Syndrome, HIV seropositivity, or intrauterine exposure to illicit substances other than cocaine and marijuana were excluded. At the 9.5-year follow-up visit, trained examiners masked to IUCE and background variables evaluated children's neuropsychological functioning using the NEPSY. The association between level of IUCE and NEPSY outcomes was evaluated in a series of linear regressions controlling for intrauterine exposure to other substances and relevant child, caregiver, and demographic variables. Results indicated that level of IUCE was associated with lower scores on the Auditory Attention and Narrative Memory tasks, both of which require auditory information processing and sustained attention for successful performance. However, results did not follow the expected ordinal, dose-dependent pattern. Children's neuropsychological test scores were also altered by a variety of other biological and psychosocial factors.

Children of treated substance-abusing mothers: a 10-year prospective study

This study examined children of substance-abusing mothers approximately 10 years after mothers' admission to drug abuse treatment, and identified maternal characteristics that may be risk factors for child behavior problems on the Child Behavior Checklist. Data were obtained from 396 mothers who were included in a sample consecutively admitted to 44 treatment programs in 13 California counties during 2000-2002. The Addiction Severity Index was administered at both intake and follow-up. Each mother reported on one child 6-17 years of age. All of the children had been exposed to drugs, either in utero or postnatally. At follow-up about 22% of the children demonstrated borderline or clinical range problem behaviors. Child behavior problems were related significantly to the mothers' ethnicity (lower among Hispanics relative to white), and problem severity in family/social relationship and mental health, marginally related to her prior medical/health problem, and not related to severity of alcohol, drug, legal and employment problems. Assisting mothers to address their family/social relationship and psychological problems may have an added value to prevent or reduce behavioral problems of their children.

Neurobehavioral and Developmental Traiectories Associated with Level of Prenatal Cocaine Exposure

INTRODUCTION

In experimental models, prenatal cocaine exposure has been found to perturb GABA and dopamine development. Clinically, abnormalities in tone, posture and state regulation are noted in early infancy but the evolution of these findings over time is not well described. The current study assesses the longitudinal effects of prenatal cocaine exposure in dose-dependent fashion on developmental & behavioral and neurological trajectories over the first 2 years of life.

METHODS

Three hundred and eighty infants, 113 cocaine-exposed, were enrolled at birth from an urban hospital from 2000 to 2004. Exposure was determined by maternal interview, segmental hair analyses (RIAH^™) in all, and meconium and urine in a subset. Developmental, behavioral and neurological assessments were carried out blind to drug exposure at 6, 12 and 24 months of age in the 306 children who returned in follow-up. Mixed-effects linear modeling (developmental growth curve) assessed change in outcome over time.

RESULTS

The mental developmental growth curve showed a negative slope (2.2 points) in adjusted analyses among cocaine-exposed children over the first 2 years of life. (p=.04), while the slope of the motor development growth curve did not. Adjusting for microcephaly at 6 months diminished the strength of the association between cocaine exposure and mental developmental growth curve (effect modification). Cocaine exposure was marginally associated with behavioral outcomes in adjusted analyses. Total Behavior scores and Orientation/Engagement scores improved with age. At 1 year of age, prenatal cocaine exposure was significantly associated with lower motor development scores. High rates of hypertonia (global and diparesis) identified at the 6-month visit dropped dramatically in the first 2 years of life: cocaine-exposed children showed a more rapid rate of resolution of hypertonia than unexposed children, with hypertonia improving 2.2 times faster among those with heavy cocaine exposure.

CONCLUSION

We found differences in mental performance over the first 2 years of life associated with prenatal cocaine exposure that was mediated by microcephaly implying that cocaine exerts a sustained teratogenic effect on brain development. Early neurological (hypertonia) and behavioral findings associated with prenatal cocaine exposure improved over time. Hypertonia did not predict long-term development impairments. Conceivably, the transient nature of neurobehavioral manifestations reflects postnatally a tendency towards homeostasis of cocaine-related embryopathic perturbations of GABA and dopaminergic systems.

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.

Predictors of intelligence at the age of 5: family, pregnancy and birth characteristics, postnatal influences, and postnatal growth

Parental education and maternal intelligence are well-known predictors of child IQ. However, the literature regarding other factors that may contribute to individual differences in IQ is inconclusive. The aim of this study was to examine the contribution of a number of variables whose predictive status remain unclarified, in a sample of basically healthy children with a low rate of pre- and postnatal complications. 1,782 5-year-old children sampled from the Danish National Birth Cohort (2003–2007) were assessed with a short form of the Wechsler Preschool and Primary Scale of Intelligence – Revised. Information on parental characteristics, pregnancy and birth factors, postnatal influences, and postnatal growth was collected during pregnancy and at follow-up. A model including study design variables and child’s sex explained 7% of the variance in IQ, while parental education and maternal IQ increased the explained variance to 24%. Other predictors were parity, maternal BMI, birth weight, breastfeeding, and the child’s head circumference and height at follow-up. These variables, however, only increased the explained variance to 29%. The results suggest that parental education and maternal IQ are major predictors of IQ and should be included routinely in studies of cognitive development. Obstetrical and postnatal factors also predict IQ, but their contribution may be of comparatively limited magnitude.

Unbalanced neuronal circuits in addiction

Through sequential waves of drug-induced neurochemical stimulation, addiction co-opts the brain's neuronal circuits that mediate reward, motivation to behavioral inflexibility and a severe disruption of self-control and compulsive drug intake. Brain imaging technologies have allowed neuroscientists to map out the neural landscape of addiction in the human brain and to understand how drugs modify it.

Externalizing problems in late childhood as a function of prenatal cocaine exposure and environmental risk

OBJECTIVE

To examine whether prenatal cocaine exposure (PCE) predicts externalizing problems in late childhood.

METHODS

Externalizing problems were assessed using caregiver, teacher, and child ratings and a laboratory task when children (N = 179; 74 cocaine exposed) were aged 8-10 years. PCE, environmental risk, sex, neonatal health, other prenatal exposures, and foster care history were examined as predictors of externalizing problems.

RESULTS

Multiple regression analyses indicated that PCE, environmental risk, and male sex explained significant variance in externalizing problems in late childhood. Models varied by source of information. PCE predicted externalizing problems for child laboratory behavior and interacted with sex because males with PCE reported more externalizing problems. PCE did not predict caregiver or teacher ratings of externalizing problems.

CONCLUSIONS

The effect of PCE on externalizing problems may persist into late childhood. The findings highlight the potential importance of including child-based measures of externalizing problems in studies of prenatal exposure.

Developmental and behavioral consequences of prenatal cocaine exposure: a review

Substance use among pregnant women continues to be a major public health concern, posing potential risk to their drug-exposed children as well as burdens on society. This review is intended to discuss the most recent literature regarding the association between in utero cocaine exposure and developmental and behavioral outcomes from birth through adolescence across various domains of functioning (growth, neurobiology, intelligence, academic achievement, language, executive functioning, behavioral regulation and psychopathology). In addition, methodological limitations, associated biological, sociodemographic and environmental risk factors and future directions in this area of research are discussed. Given the large number of exposed children in the child welfare system and the increased need for medical, mental health and special education services within this population, more definitively documenting associations between prenatal cocaine exposure and later child outcomes is essential in order to be able to prospectively address the many significant public health, economic and public policy implications.

Understanding the diverse needs of children whose parents abuse substances

In this review, we consider the potential service needs of children of substance abusing parents based on what we know about the risk outcomes faced by these children and the parenting deficits often present in these families. Importantly, our review does not address the etiological role of parental substance abuse in children's negative outcomes but instead we discuss the complex inter-related risk factors that often co-occur with and exacerbate risk associated with parental alcohol and drug use. We first review studies showing the elevated risk that children of substance abusing parents face in general for poorer academic functioning; emotional, behavioral, and social problems; and an earlier onset of substance use, faster acceleration in substance use patterns, and higher rates of alcohol and drug use disorders. We then review studies showing contextual risk factors for children of substance abusing parents, including parenting deficits (less warmth, responsiveness, and physical and verbal engagement as well as harsher and more over-involved interaction styles), greater risk for child maltreatment, and less secure attachment patterns. We conclude with a discussion of future directions for research and guidelines for professionals working with children and their families where parental substance abuse is present.

Adolescents with and without gestational cocaine exposure: Longitudinal analysis of inhibitory control, memory and receptive language

Preclinical studies of gestational cocaine exposure (GCE) show evidence of changes in brain function at the anatomical, physiological, and behavioral levels, to include effects on developing dopaminergic systems. In contrast, human studies have produced less consistent results, with most showing small effects or no effects on developmental outcomes. Important changes in brain structure and function occur through adolescence, therefore it is possible that prenatal cocaine exposure has latent effects on neurocognitive (NC) outcome that do not manifest until adolescence or young adulthood. We examined NC function using a set of 5 tasks designed to tap 4 different systems: inhibitory control, working memory, receptive language, and incidental memory. For each NC task, data were collected longitudinally at ages 12, 14.5 and 17 years and examined using generalized estimating equations. One hundred and nine children completed at least two of the three evaluations. Covariates included in the final model were assessment number, gender, participant age at first assessment, caregiver depression, and two composites from the Home Observation for Measurement of the Environment (HOME), Environmental Stimulation and Parental Nurturance. We found no cocaine effects on inhibitory control, working memory, or receptive language (p=0.18). GCE effects were observed on incidental face memory task (p=0.055), and GCE by assessment number interaction effects were seen on the incidental word memory task (p=0.031). Participant performance on inhibitory control, working memory, and receptive language tasks improved over time. HOME Environmental Stimulation composite was associated with better receptive language functioning. With a larger sample size smaller differences between groups may have been detected. This report shows no evidence of latent effects of GCE on inhibitory control, working memory, or receptive language. GCE effects were observed on the incidental face memory task, and GCE by assessment number interaction effects was seen on the incidental word memory task.

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.

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.

The effects of prenatal cocaine on language development at 10 years of age

OBJECTIVE

To examine the long term effects of prenatal cocaine exposure (PCE) on the language development of 10-year-old children utilizing a prospective design, controlling for confounding drug and environmental factors.

PARTICIPANTS

Children exposed to cocaine in utero (PCE; n=175) and non-exposed children (NCE; n=175) were followed prospectively to 10years of age and were compared on language subscales of the Test of Language Development-Intermediate 3rd Edition (TOLD-I:3) and phonological processing as measured by the Comprehensive Test of Phonological Processing (CTOPP).

METHODS

Multivariate analysis of covariance (MANCOVA), linear regression, and logistic regressions were used to evaluate the relationship of prenatal cocaine exposure to language development, while controlling for confounders.

RESULTS

After controlling for confounding variables, prenatal cocaine effects were observed for specific aspects of language including syntax (Sentence Combining subtest of the TOLD-I:3, p=0.001), semantics (Malopropism subtest of the TOLD-I:3, p=0.05) and phonological processing (Phonological Awareness subscale, p=0.01). The caregiver factors of vocabulary, HOME, and psychological symptoms also had consistent effects on language subtests and phonological processing scores. Children with PCE who experienced foster or adoptive care had enhanced language development compared to those living with birth mothers or in relative care. Cocaine exposed girls had lower scores on the phonological awareness subscale of the CTOPP than non-exposed girls.

CONCLUSIONS

PCE has subtle effects on specific aspects of language development and phonological processing at age 10, even after controlling for confounding variables. Environmental factors (i.e., postnatal lead exposure, home environment, and caregiver vocabulary and psychological symptoms) also impact language skills at 10years. Adoptive or foster care appears to enrich PCE children's linguistic environment and protects children against language delay in the PCE sample.

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.

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.

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.

Fetal origins of mental health: evidence and mechanisms

The concept of fetal programming states that changes in the fetal environment during sensitive periods of organ development may cause long-lasting changes in the structure and functioning of these organs later in life and influence the risk for chronic diseases such as coronary heart disease and type 2 diabetes. Fetal growth is a summary marker of the fetal environment and is reflected by relatively easy-to-obtain measures of size at birth such as birth weight. In the last two decades, a body of evidence emerged linking fetal growth with behavioural and mental health outcomes later in life. Cognitive functioning and behavioural problems in childhood, in particular inattention/hyperactivity, have been shown to be inversely related to fetal growth. Although results are mixed, risk for personality disorders and schizophrenia seems to be linked with fetal growth and adversity, while the evidence for mood disorders is weak. Vulnerability for psychopathology may also be influenced by prenatal adversity. There is evidence for associations of fetal growth with temperament in childhood as well as stress reactivity and distress. The associations of fetal growth with mental health later in life are potentially caused by specific prenatal factors such as maternal smoking, alcohol, toxins/drugs, nutrition, psychosocial stress and infection during pregnancy. The mechanisms likely involve changes in neurodevelopment and in the set point of neuroendocrine systems, and there is evidence that prenatal adversity interacts with genetic and postnatal environmental factors. Future studies should examine the effects of specific prenatal factors and attempt to disentangle genetic and prenatal environmental effects.

The effect of maternal smoking during pregnancy on intellectual disabilities among 8-year-old children

Prenatal tobacco smoke exposure has been implicated as a risk factor for cognitive deficits in children. The purpose of this study is to examine the association between prenatal tobacco smoke exposure and diagnosis of intellectual disabilities (ID) among 8-year-old children living in Arkansas, Georgia, North Carolina and Utah. In 2002 and 2004, 965 ID case children were identified through a surveillance network and compared with the population of children born in the surveillance region during the same period (n = 104 607). Prenatal tobacco smoke exposure was determined from birth certificates. We estimated the effect of prenatal tobacco smoke exposure (none, <10, 10-19 and > or =20 cigarettes per day) on ID using logistic regression. Generally, the risk of ID was mildly elevated among children whose mothers smoked > or =20 cigarettes per day during pregnancy [RR 1.34; 95% (confidence interval) CI 0.96, 1.87] after adjustment for maternal education, maternal race, maternal age, marital status, child sex, birth year and study site. However, the effect of exposure to > or =20 cigarettes per day significantly differed for males [RR 1.77, 95% CI 1.20, 2.62] compared with females [RR 0.81, 95% CI 0.44, 1.50]. Supplemental analyses reveal substantial confounding of this relationship by socio-economic indicators. A differential effect of tobacco smoke exposure on the risk of ID is suggested for males and females and deserves further investigation; however, the interpretation is tempered by the potential for residual confounding.

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.

Cognitive function and overweight in preschool children

The authors assessed the association between cognitive function and incidence and maintenance of overweight in preschool children. A population-based birth cohort was established in Menorca, Spain, between 1997 and 1999 (n = 482). Body mass index (weight (kg)/height (m)(2)) was measured at ages 4 years and 6 years (n = 421). At age 4 years, children were assessed for cognitive function (McCarthy Scales of Children's Abilities) (n = 395). After multivariable adjustment for a wide range of factors, including maternal education and body mass index, children with higher general cognition at age 4 years had a lower likelihood of being overweight (odds ratio = 0.47, 95% confidence interval (CI): 0.25, 0.88) at age 6 years. Children with higher general cognition at age 4 years had a lower likelihood of maintaining an unhealthy weight status (being at risk of overweight or overweight) between ages 4 years and 6 years, as well as worsening weight status over time, than children who maintained a healthy weight (odds ratios were 0.78 (95% CI: 0.54, 1.14) and 0.77 (95% CI: 0.51, 1.14), respectively). When specific dimensions of cognitive function were assessed, associations were mainly found for verbal and executive function areas. Children with higher cognitive function in early life might be at decreased risk of overweight later in childhood.

Children with and without gestational cocaine exposure: a neurocognitive systems analysis

BACKGROUND

Concern for effects of gestational cocaine exposure (GCE) on human neurocognitive (NC) development is based on effects of cocaine on blood flow to the fetus and impact of cocaine on developing monoaminergic systems. GCE has been shown to affect language, attention and perceptual reasoning skills.

OBJECTIVE

Our objective was to investigate effects of GCE on 7 NC systems, assessed behaviorally in middle school-aged, low socioeconomic status subjects followed prospectively since birth.

METHODS

55 GCE and 65 non-exposed Control subjects were tested with a battery of 14 tasks adapted from neuroimaging and lesion literature designed to tap 3 frontal systems (Cognitive Control, Working Memory, and Reward Processing) and 4 non-frontal systems (Language, Memory, Spatial Cognition, and Visual Cognition). Using multivariate analysis of covariance, we assessed the relation between NC functioning and GCE status with the following covariates: age at testing; gender; gestational exposure to cigarettes, alcohol and marijuana; foster care placement; caregiver current cocaine use; and two indices of childhood environment.

RESULTS

None of the analyses showed an effect of GCE on NC function. In contrast, child characteristics, including age at testing and childhood environment, were associated with NC function.

CONCLUSIONS

In this cohort there is either no effect of GCE on NC function at middle school age, or that effect is less pronounced than the effect of age or childhood environment.

Health consequences of illegal drug use

PURPOSE OF REVIEW

The aim of this article is to review recent research on the health consequences of illegal drug use and possible risk factors, with a particular focus on prospective evidence.

RECENT FINDINGS

Mortality studies have revealed qualitative and quantitative changes in causes of death among heroin and injecting drug users (IDUs), probably due to increasing exposure to harm reduction programs, the introduction of highly active antiretroviral therapy (HAART), the aging of drug users, and rising concurrent use of illegal drugs and prescription drugs. For morbidity, nonfatal overdose is still one of the most important concerns; likewise the higher prevalence of hepatitis C among non-IDUs and hepatitis A, B, C coinfection. Cannabis use has been consistently reported to be associated with the emergence of psychotic symptoms, yet that seems not to be the case for anxiety and depressive disorders. Use of 3,4 methylenedioxymethamphetamine (MDMA) has been linked with short-term negative effects on cognitive performance (i.e. visual memory). A series of longitudinal studies have shown enduring unfavorable effects of prenatal cocaine and marijuana exposure on children's physical, cognitive, and language development.

SUMMARY

Prospective evidence on illegal drug use in particular subpopulations may be needed to better understand health problems among users at different life stages and the possible long-term effects.

An Empirical Theory of the Development of Homicide within Individuals

There have been many attempts to explain violent behavior, identify its causes, and predict its occurrence among youth and adults. Research and theoretical constructions have dealt with such far-ranging aspects as childhood health, peer and parental interactions, neuropsychological function, school and community support, and substance use and dependency. Theories have tended to focus on one or a few of these aspects, but there is an effort by many researchers to converge on an integrated approach. By demonstrating unique risk patterns in random samples of later-homicidal abused infants, children, and youth, violent and homicidal delinquents, and homicidal adults, five studies by Zagar and colleagues provide the best current empirical evidence for a view of the development of delinquency as a process of accumulating risks. These risks begin with prenatal substance exposure and continue with abusive or neglectful parenting, academic failure, court contacts, compromised executive function and resultant poor social functioning. Analysis by sex shows that males' and females' risks are virtually identical. Various theories are evaluated with respect to these empirical risk patterns for development of violence and homicide. A proposal for the necessary elements of a successful, overarching explanatory theory is offered.

Cocaine-exposed infant behavior during Still-Face: risk factor analyses

Prenatal cocaine exposure and the role of gender were evaluated using risk factor analyses to determine whether 6-month-old cocaine-exposed male infants demonstrated greater disruptions in infant-caregiver socioemotional interactions during a Still-Face test. Overall, non-cocaine-exposed infants spent more time looking at toys, compared with cocaine-exposed infants; nonexposed female infants spent more time scanning the environment, compared with nonexposed male infants. When caregiver behavior during the Still-Face was evaluated, differences emerged in amount of time the caregiver spent vocalizing to the infant. She vocalized more to a cocaine-exposed infant compared with a nonexposed one; she reduced vocalizing more during the test if the cocaine-exposed infant was female. An exposure by gender interaction emerged in the amount of change in caregiver vocalizations; however, the overarching hypothesis that male cocaine-exposed infants are at higher risk than nonexposed male, nonexposed female, and cocaine-exposed female infants was not supported. Because this interaction was evident in this cohort at 24 months, future research is needed to determine at what age an interaction begins to emerge in this cohort.