Cocaine exposure and children: the meaning of subtle effects

Early emotional caregiving environment and associations with memory performance and hippocampal volume in adolescents with prenatal drug exposure

Early adversities, including prenatal drug exposure (PDE) and a negative postnatal emotional caregiving environment, impact children's long-term development. The protracted developmental course of memory and its underlying neural systems offer a valuable framework for understanding the longitudinal associations of pre- and postnatal factors on children with PDE. This study longitudinally examines memory and hippocampal development in 69 parent-child dyads to investigate how the early caregiving emotional environment affects children with PDE's neural and cognitive systems. Measures of physical health, drug exposure, caregiver stress, depression, and distress were collected between 0 and 24 months At age 14 years, adolescents completed multiple measures of episodic memory, and at ages 14 and 18 years, adolescents underwent magnetic resonance imaging (MRI) scans. Latent constructs of episodic memory and the caregiving environment were created using Confirmatory Factor Analysis. Multiple regressions revealed a negative emotional caregiving environment during infancy was associated with poor memory performance and smaller left hippocampal volumes at 14 years. Better memory performance at 14 years predicted larger right hippocampal volume at 18 years. At 18 years, the association between the emotional caregiving environment and hippocampal volume was moderated by sex, such that a negative emotional caregiving environment was associated with larger left hippocampal volumes in males but not females. Findings suggest that the postnatal caregiving environment may modulate the effects of PDE across development, influencing neurocognitive development.

The association of prenatal cocaine exposure with expressive and receptive language skills, phonological processing and reading ability at age 17

OBJECTIVE

Prenatal cocaine exposure (PCE) has been associated with small but significant effects on language development in childhood and early adolescence. This study examined whether this association persists into later adolescence and what relationship language skills may have with reading proficiency in this population.

METHODS

Enrolled were 338 (167 with PCE, 171 with NCE or no cocaine exposure) 17-year-olds recruited at birth who, together with their current caregiver, were seen as part of a 17-year follow-up. Participants were given assessments of reading achievement (WIAT-III), receptive and expressive language (CELF-IV), and phonological processing (CTOPP). Relationships between PCE status and language outcomes were modeled using multiple linear regression controlling for environmental and caregiver factors, and other prenatal substance exposures.

RESULTS

Adolescents with PCE scored lower in areas of phonological processing and reading related skills compared to adolescents with NCE. PCE by sex interactions were identified on language, memory and spoken language comprehension, with lower scores for girls with PCE compared to girls with NCE.

CONCLUSION

These findings suggest the persistence of PCE's relationship with phonological awareness well into adolescence. PCE was also associated with lower scores on measures of skills related to reading ability, which may be a manifestation of the observed deficits in phonological processing.

Fifty Years of Research on Prenatal Substances: Lessons Learned for the Opioid Epidemic

Current efforts to design research on developmental effects of prenatal opioid exposure can benefit from knowledge gained from 50 years of studies of fetal alcohol and prenatal drug exposures such as cocaine. Scientific advances in neurobiology, developmental psychopathology, infant assessments, genetics, and imaging support the principles of developmental neurotoxicology that guide research in prenatal exposures. Important to research design is accurate assessment of amount, frequency, and timing of exposure which benefits from accurate self-report and biomarkers of exposure. Identifying and control of pre- and postnatal factors that impact development are difficult and dependent on appropriate research design and selection of comparison groups and measurement of confounding, mediating, and moderating variables. Polysubstance exposure has increased due to the number of prescribed and nonprescribed substances used by pregnant women and varying combinations of drugs may have differential effects on the outcome. Multiple experimental and clinical assessments of infant behavior have been developed but predicting outcome before 18-24 months of age remains difficult. With some exceptions, prenatal substance exposure effect sizes have been small, and cognitive and behavioral effects tend to be specific rather than global. Studies require large sample sizes, adequate retention, and support for social services in at-risk samples. The ethical and legal contexts and stigma associated with drug/alcohol use disorder should be considered in order to prevent harm to families in research programs. Recognition of the pervasive use of addictive substances in this nation should lead to broad scientific efforts to understand how substances affect child outcomes and to initiate prevention and intervention where needed.

Effect Sizes, Power, and Biases in Intelligence Research: A Meta-Meta-Analysis

In this meta-study, we analyzed 2442 effect sizes from 131 meta-analyses in intelligence research, published from 1984 to 2014, to estimate the average effect size, median power, and evidence for bias. We found that the average effect size in intelligence research was a Pearson's correlation of 0.26, and the median sample size was 60. Furthermore, across primary studies, we found a median power of 11.9% to detect a small effect, 54.5% to detect a medium effect, and 93.9% to detect a large effect. We documented differences in average effect size and median estimated power between different types of intelligence studies (correlational studies, studies of group differences, experiments, toxicology, and behavior genetics). On average, across all meta-analyses (but not in every meta-analysis), we found evidence for small-study effects, potentially indicating publication bias and overestimated effects. We found no differences in small-study effects between different study types. We also found no convincing evidence for the decline effect, US effect, or citation bias across meta-analyses. We concluded that intelligence research does show signs of low power and publication bias, but that these problems seem less severe than in many other scientific fields.

Associations of Prescribed ADHD Medication in Pregnancy with Pregnancy-Related and Offspring Outcomes: A Systematic Review

BACKGROUND

Increasing numbers of reproductive-aged women are using attention-deficit/hyperactivity disorder (ADHD) medications. Findings from studies exploring the safety of these medications during pregnancy are mixed, and it is unclear whether associations reflect causal effects or could be partially or fully explained by other factors that differ between exposed and unexposed offspring.

OBJECTIVES

The aim of this systematic review was to evaluate the adverse pregnancy-related and offspring outcomes associated with exposure to prescribed ADHD medication during pregnancy with a focus on how studies to date have handled the influence of confounding.

METHODS

We searched PubMed, Embase, PsycINFO, and Web of Science up to 1 July 2019 without any restrictions on language or date of publication. We included all observational studies (e.g., cohort studies, case-control studies, case-crossover studies, cross-sectional studies, and registry-based studies) with pregnant women of any age or from any setting who were prescribed ADHD medications and evaluated any outcome, including both short- and long-term maternal and offspring outcomes. Two independent authors then used the Newcastle-Ottawa Scale to rate the quality of the included studies.

RESULTS

Eight cohort studies that estimated adverse pregnancy-related and offspring outcomes associated with exposure to ADHD medication during pregnancy were included in the qualitative review. The included studies had substantial methodological differences in data sources, type of medications examined, definitions of studied pregnancy-related and offspring outcomes, types of control groups, and confounding adjustment. There was no convincing evidence for teratogenic effects according to the relative risk of pregnancy-related and offspring outcomes, and the observed differences in absolute risks were overall small in magnitude. Adjustment for confounding was inadequate in most studies, and none of the included studies adjusted for ADHD severity in the mothers.

CONCLUSION

The current evidence does not suggest that the use of ADHD medication during pregnancy results in significant adverse consequences for mother or offspring. However, the data are too limited to make an unequivocal recommendation. Therefore, physicians should consider whether the advantages of using ADHD medication outweigh the potential risks for the developing fetus according to each woman's specific circumstances. Future research should attempt to triangulate research findings based on a combination of different designs that differ in their underlying strengths and limitations and should investigate specific confounding factors, the potential impact of timing of exposure, and potential long-term outcomes in the offspring.

Prenatal Opioid Exposure: Neurodevelopmental Consequences and Future Research Priorities

Neonatal opioid withdrawal syndrome (NOWS) has risen in prevalence from 1.2 per 1000 births in 2000 to 5.8 per 1000 births in 2012. Symptoms in neonates may include high-pitched cry, tremors, feeding difficulty, hypertonia, watery stools, and breathing problems. However, little is known about the neurodevelopmental consequences of prenatal opioid exposure in infancy, early childhood, and middle childhood. Even less is known about the cognitive, behavioral, and academic outcomes of children who develop NOWS. We review the state of the literature on the neurodevelopmental consequences of prenatal opioid exposure with a particular focus on studies in which NOWS outcomes were examined. Aiming to reduce the incidence of prenatal opioid exposure in the near future, we highlight the need for large studies with prospectively recruited participants and longitudinal designs, taking into account confounding factors such as socioeconomic status, institutional variations in care, and maternal use of other substances, to independently assess the full impact of NOWS. As a more immediate solution, we provide an agenda for future research that leverages the National Institutes of Health Environmental Influences on Child Health Outcomes program to address many of the serious methodologic gaps in the literature, and we answer key questions regarding the short- and long-term neurodevelopmental health of children with prenatal opioid exposure.

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.

Infants' early visual attention and social engagement as developmental precursors to joint attention

This study examined infants' early visual attention (at 1 month of age) and social engagement (4 months) as predictors of their later joint attention (12 and 18 months). The sample (n = 325), drawn from the Maternal Lifestyle Study, a longitudinal multicenter project conducted at 4 centers of the National Institute of Child Health and Human Development Neonatal Research Network, included high-risk (cocaine-exposed) and matched noncocaine-exposed infants. Hierarchical regressions revealed that infants' attention orienting at 1 month significantly predicted more frequent initiating joint attention at 12 (but not 18) months of age. Social engagement at 4 months predicted initiating joint attention at 18 months. Results provide the first empirical evidence for the role of visual attention and social engagement behaviors as developmental precursors for later joint attention outcome. (PsycINFO Database Record

Managing Maternal Substance Use in the Perinatal Period: Current Concerns and Treatment Approaches in the United States and Australia

Substance use in pregnancy can have adverse effects on mother and fetus alike. Australia and the US are countries with high levels of substance use and policies advising abstinence, although the Australian approach occurs within a broader framework of harm minimization. Less attention has been paid to treatment of the mothers' substance use and what is considered gold standard. This is despite evidence that prior substance use in pregnancy is the most important factor in predicting future substance use in pregnancy. This paper draws together information from both the peer-reviewed and gray literature to provide a contemporary overview of patterns and outcomes of the three main drugs, alcohol, tobacco, and cannabis, used in Australia and the US during pregnancy and discusses what are considered gold standard screening and treatment approaches for these substances. This paper does not set out to be a comprehensive review of the area but rather aims to provide a concise summary of current guidelines for policy makers and practitioners who provide treatment for women who use substances in pregnancy.

A Glass Half Full? Harm Reduction among Pregnant Women Who Use Cocaine

The current research challenges the popular assumption that pregnant women who use drugs are either unable or unwilling to take steps to promote a healthy pregnancy. Many qualitative studies have found that pregnant women who use drugs may engage in harm reduction strategies. These findings were confirmed in the present study, which uses data collected as part of the 1992 National Institute on Drug Abuse survey of women who delivered live-born infants in DC hospitals. These data also highlight the disadvantaged socioeconomic, emotional, and physical position of women who use cocaine relative to other women. The findings suggest a need for policies and responses to maternal drug use that recognize many women's desire to promote a healthy pregnancy as well as their diminished social and physical circumstances.

Extrinsic Barriers to Substance Abuse Treatment among Pregnant Drug Dependent Women

The objective of this qualitative study was to examine extrinsic barriers to substance abuse treatment among pregnant and parenting women enrolled in residential perinatal substance abuse treatment programs in Northern California. Life history interviews were conducted with 36 women to examine help-seeking behaviors before treatment enrollment. Data analysis used the analytic framework of Mandelbaum (1973) to describe dimensions, turnings, and adaptations of participants. Results indicated that the majority (n = 34) of participants sought prenatal care but identified fear of punitive actions from helping institutions and individuals as a major barrier. Other extrinsic barriers included substance abuse treatment program barriers, partners, the status of opiate dependency, and the status of pregnancy. Biological, socio-cultural, and psychosocial dimensions of participants' care-seeking experiences were identified. The turning was pregnancy and adaptations included preserving the family, managing fear and manifesting faith. Findings describe the transformation of the therapeutic alliance and the gendered impact of two decades of the War on Drugs in the United States. Participants' coping strategies suggest that the desire for child custody and concern for fetal and child well-being was a priority and motivated care seeking despite extrinsic barriers perceived to be threatening to the woman's safety and autonomy.

Effects of environmental enrichment on behavioral deficits and alterations in hippocampal BDNF induced by prenatal exposure to morphine in juvenile rats

Prenatal morphine exposure throughout pregnancy can induce a series of neurobehavioral and neurochemical disturbances by affecting central nervous system development. This study was designed to investigate the effects of an enriched environment on behavioral deficits and changes in hippocampal brain-derived neurotrophic factor (BDNF) levels induced by prenatal morphine in rats. On pregnancy days 11-18, female Wistar rats were randomly injected twice daily with saline or morphine. Offspring were weaned on postnatal day (PND) 21. They were subjected to a standard rearing environment or an enriched environment on PNDs 22-50. On PNDs 51-57, the behavioral responses including anxiety and depression-like behaviors, and passive avoidance memory as well as hippocampal BDNF levels were investigated. The light/dark (L/D) box and elevated plus maze (EPM) were used for the study of anxiety, forced swimming test (FST) was used to assess depression-like behavior and passive avoidance task was used to evaluate learning and memory. Prenatal morphine exposure caused a reduction in time spent in the EPM open arms and a reduction in time spent in the lit side of the L/D box. It also decreased step-through latency and increased time spent in the dark side of passive avoidance task. Prenatal morphine exposure also reduced immobility time and increased swimming time in FST. Postnatal rearing in an enriched environment counteracted with behavioral deficits in the EPM and passive avoidance task, but not in the L/D box. This suggests that exposure to an enriched environment during adolescence period alters anxiety profile in a task-specific manner. Prenatal morphine exposure reduced hippocampal BDNF levels, but enriched environment significantly increased BDNF levels in both saline- and morphine-exposed groups. Our results demonstrate that exposure to an enriched environment alleviates behavioral deficits induced by prenatal morphine exposure and up-regulates the decreased levels of BDNF. BDNF may contribute to the beneficial effects of an enriched environment on prenatal morphine-exposed to rats.

The contributions of early adverse experiences and trajectories of respiratory sinus arrhythmia on the development of neurobehavioral disinhibition among children with prenatal substance exposure

Neurobehavioral disinhibition (ND) is a complex condition reflecting a wide range of problems involving difficulties with emotion regulation and behavior control. Respiratory sinus arrhythmia (RSA) is a physiological correlate of emotion regulation that has been studied in a variety of at-risk populations; however, there are no studies of RSA in children with ND. Data were drawn from a prospective longitudinal study of prenatal substance exposure that included 1,073 participants. Baseline RSA and RSA reactivity to an attention-demanding task were assessed at 3, 4, 5, and 6 years. ND was assessed at ages 8/9, 11, and 13/14 years via behavioral dysregulation and executive dysfunction composite measures. Greater exposure to early adversity was related to less RSA reactivity at 3 years, increases in RSA reactivity from ages 3 to 6 years, and increased behavioral dysregulation from ages 8/9 to 13/14. RSA reactivity was examined as a moderator of the association between early adversity and changes in ND. A significant Early Adversity × RSA Reactivity quadratic interaction revealed that children with decelerations in RSA reactivity exhibited increases in behavioral dysregulation, regardless of their exposure to early adversity. However, greater exposure to early adversity was related to greater increases in behavioral dysregulation, but only if children exhibited accelerations in RSA reactivity from ages 3 to 6 years. The results contribute to our understanding of how interactions across multiple levels of analysis contribute to the development of ND.

Translational analysis of effects of prenatal cocaine exposure on human infant cries and rat pup ultrasonic vocalizations

Spectral and temporal features of human infant crying may detect neurobehavioral effects of prenatal cocaine exposure (PCE). Finding comparable measures of rodent ultrasonic vocalizations (USVs) would promote translational analyses by controlling the effects of correlated variables that confound human studies. To this end, two studies examined the sensitivity of similar acoustic structures in human infant and rat pup vocalizations to effects of PCE. In Study 1, cry sounds of 107 one month-old infants were spectrum analyzed to create a novel set of measures and to detect the presence of hyperphonation - a qualitative shift to an atypically high fundamental frequency (basic pitch) associated with neurobehavioral insult. Infants with PCE were compared to infants with prenatal polydrug-exposure (PPE) without cocaine and with infants in a standard comparison (SC) group with no prenatal drug exposure. In Study 2, USVs of 118 five day-old rat pups with either PCE, prenatal saline exposure or no prenatal exposures were spectrum analyzed to detect the presence of frequency shifts - acoustic features that have a frequency waveform similar to that of hyperphonation. Results of study 1 showed PCE had two sets of sex-dependent effects on human infants: PCE males had higher pitched cries with more dysphonation (turbulence); PCE females had longer pauses between fewer cry sounds that were of lower amplitude than comparison groups. PCE and PPE infants had more cries with hyperphonation than SC infants. In study 2, PCE pups had a greater percentage of USVs with shift in the acoustic structure than pups in the two control groups. As such, the novel measures of human infant crying and rat pup USVs were sensitive to effects of PCE. These studies provide the first known translational analysis of similar acoustic structures of vocalizations in two species to detect adverse effects of prenatal drug exposure.

Structural brain imaging in children and adolescents following prenatal cocaine exposure: preliminary longitudinal findings

The brain morphometry of 21 children, who were followed from birth and underwent structural brain magnetic resonance imaging at 8-10 years, was studied. This cohort included 11 children with prenatal cocaine exposure (CE) and 10 noncocaine-exposed children (NCE). We compared the CE versus NCE groups using FreeSurfer to automatically segment and quantify the volume of individual brain structures. In addition, we created a pediatric atlas specifically for this population and demonstrate the enhanced accuracy of this approach. We found an overall trend towards smaller brain volumes among CE children. The volume differences were significant for cortical gray matter, the thalamus and the putamen. Here, reductions in thalamic and putaminal volumes showed a robust inverse correlation with exposure levels, thus highlighting effects on dopamine-rich brain regions that form key components of brain circuitry known to play important roles in behavior and attention. Interestingly, head circumferences (HCs) at birth as well as at the time of imaging showed a tendency for smaller size among CE children. HCs at the time of imaging correlated well with the cortical volumes for all subjects. In contrast, HCs at birth were predictive of the cortical volume only for the CE group. A subgroup of these subjects (6 CE, 4 NCE) was also scanned at 13-15 years of age. In subjects who were scanned twice, we found that the trend for smaller structures continued into teenage years. We found that the differences in structural volumes between the CE and NCE groups are largely diminished when the HCs are controlled for or matched by study design. Participants in this study were drawn from a unique longitudinal cohort and, while the small sample size precludes strong conclusions regarding the longitudinal findings reported, the results point to reductions in HCs and in specific brain structures that persist through teenage years in children who were exposed to cocaine in utero.

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.

Reactivity and regulation of motor responses in cocaine-exposed infants

Effects of prenatal exposure to cocaine on the reactivity and regulation of the motor system of 825 four-month-old infants enrolled in the Maternal Lifestyle Study were examined. Videotaped assessments of 338 cocaine-exposed (CE) infants and 487 non-exposed comparison infants were coded by examiners masked to exposure status. Exposure status was determined by meconium assay and maternal self-report of prenatal cocaine use. Infants were presented with a series of 17 visual, auditory and tactile stimuli for 30-s each. Intensity and latency of limb movement responses on a subset of items were analyzed to test the following hypotheses: CE infants are more active in general; CE infants exhibit increased movement levels for a larger proportion of time in response to stimulation; the motor systems of CE infants are more reactive to stimulation (e.g., shorter latencies to respond); and CE infants are poorer regulators of the motor system.

RESULTS

CE infants were not more active in general and data do not indicate a more highly reactive motor system. However, CE infants exhibited increased movement levels for a larger proportion of time in response to stimulation. Additional analysis of movement exhibited during three tactile items found increased movement lability in CE infants and different patterns of responding, suggesting that the effects of prenatal cocaine exposure on the motor system may vary by context. Covariate effects for tobacco, alcohol, and marijuana are also reported.

Language outcomes at 12 years for children exposed prenatally to cocaine

PURPOSE

In this study, the authors aimed to examine the long-term effects of prenatal cocaine exposure (PCE) on the language development of 12-year-old children using a prospective design, controlling for confounding prenatal drug exposure and environmental factors.

METHOD

Children who were exposed to cocaine in utero (PCE; n = 183) and children who were not exposed to cocaine (i.e., no cocaine exposure [NCE]; n = 181) were followed prospectively from birth to 12 years of age and were compared on language subtests of the Test of Language Development-Intermediate, Third Edition ( Hammill & Newcomer, 1997b), and phonological processing as measured by the Comprehensive Test of Phonological Processing ( Wagner & Torgesen, 1999). The authors evaluated the relationship of PCE to language development through a multivariate analysis of covariance and regression analyses while controlling for confounders.

RESULTS

Results show that PCE has small effects on specific aspects of language, including syntax and phonological processing. The caregiver variables of lower maternal vocabulary, more psychological symptoms, and a poorer home environment also had consistent effects on language and phonological processing scores.

CONCLUSIONS

These findings suggest that PCE continues to have small, subtle effects on specific aspects of language at age 12 years. Phonological processing skills were significantly related to the reading outcomes of letter-word identification, reading fluency, and reading comprehension, indicating that PCE also has small but lasting effects on the language skills that are related to later literacy skills.

The role of prenatal substance exposure and early adversity on parasympathetic functioning from 3 to 6 years of age

We employed latent growth curve analysis to examine trajectories of respiratory sinus arrhythmia (RSA) from 3 to 6 years among children with varying levels of prenatal substance exposure and early adversity. Data were drawn from a prospective longitudinal study of prenatal substance exposure that included 1,121 participants. Baseline RSA and RSA reactivity to an attention-demanding task were assessed at 3, 4, 5, and 6 years. Overall, there were significant individual differences in the trajectories of RSA reactivity, but not baseline RSA, across development. Greater levels of prenatal substance exposure, and less exposure to early adversity, were associated with increased RSA reactivity at 3 years, but by 6 years, both were associated with greater RSA reactivity. Prenatal substance exposure had an indirect influence through early adversity on growth in RSA reactivity. Results are in support of and contribute to the framework of allostatic load.

Prenatal and gestational cocaine exposure: Effects on the oxytocin system and social behavior with implications for addiction

Drug abuse during pregnancy is a major public health concern, with negative consequences throughout development. Prenatal cocaine exposure (PCE) in rats produces social behavior deficits with corresponding changes in neuroendocrine and monoaminergic signaling. The relevance of parental care in social behavior maturity cannot be ignored, and gestational exposure to cocaine severely disrupts parental care, thus impacting the early environment of the offspring. Oxytocin (Oxt) is critical in regulating social behaviors and central levels are disrupted following acute and chronic cocaine (CC) treatment in postpartum rat dams, coincident with deficits in maternal care. We will discuss studies aimed to determine the relative contribution of PCE and CC-induced deficits in maternal care to social behaviors and Oxt signaling across development. PCE results in decreased social (including parental) behaviors in adolescence and adulthood. PCE is also associated with increased aggression in adults. Rearing by CC-exposed mothers synergistically increases the behavioral effects of PCE. Rearing by CC-exposed mothers, but not PCE, disrupts Oxt levels and mRNA in regions relevant to social behavior, but does not affect receptors in postpartum adult offspring. Preliminary work indicates that PCE/CC rearing has dynamic effects on Oxt levels and receptors in neonatal rat pups, suggesting very early regulation of Oxt signaling. This work highlights how the interactive role of Oxt signaling and behavioral context throughout development can be derailed by drug abuse during pregnancy. The relevance of disrupted Oxt to intergenerational transmission of addiction is briefly discussed.

Memory ability and hippocampal volume in adolescents with prenatal drug exposure

The objective of the present study was to examine the influence of prenatal drug exposure (PDE) on memory performance and supporting brain structures (i.e., hippocampus) during adolescence. To achieve this goal, declarative memory ability and hippocampal volume were examined in a well-characterized sample of 138 adolescents (76 with a history of PDE and 62 from a non-exposed comparison group recruited from the same community, mean age=14 years). Analyses were adjusted for: age at time of the assessments, gender, IQ, prenatal exposure to alcohol and tobacco, and indices of early childhood environment (i.e., caregiver depression, potential for child abuse, and number of caregiver changes through 7 years of age). Results revealed that adolescents with a history of PDE performed worse on the California Verbal Learning Test-Child Version (CVLT-C), and story recall from the Children's Memory Scale (CMS), and had larger hippocampal volumes, even after covariate adjustment. Hippocampal volume was negatively correlated with memory performance on the CVLT-C, with lower memory scores associated with larger volumes. These findings provide support for long-term effects of PDE on memory function and point to neural mechanisms that may underlie these outcomes.

Psychopathology and special education enrollment in children with prenatal cocaine exposure

OBJECTIVE

This study evaluated how enrollment in special education services in 11-year-old children relates to prenatal cocaine exposure (PCE), psychopathology, and other risk factors.

METHODS

Participants were 498 children enrolled in The Maternal Lifestyle Study, a prospective, longitudinal, multisite study examining outcomes of children with PCE. Logistic regression was used to examine the effect of PCE and psychopathology on enrollment in an individualized education plan (IEP; a designation specific to children with special education needs), with environmental, maternal, and infant medical variables as covariates.

RESULTS

PCE, an interaction of PCE and oppositional defiant disorder, child attention-deficit hyperactivity disorder, parent-reported internalizing behaviors, and teacher-reported externalizing behaviors, predicted enrollment in an IEP. Other statistically significant variables in the model were male gender, low birth weight, being small for gestational age, white race, caregiver change, low socioeconomic status, low child intelligence quotient, caregiver depression, and prenatal marijuana exposure.

CONCLUSIONS

PCE increased the likelihood of receiving an IEP with adjustment for covariates. Psychopathology also predicted this special education outcome, in combination with and independent of prenatal cocaine exposure.

Enhanced dopamine D1 and BDNF signaling in the adult dorsal striatum but not nucleus accumbens of prenatal cocaine treated mice

Previous work from our group and others utilizing animal models have demonstrated long-lasting structural and functional alterations in the meso-cortico-striatal dopamine pathway following prenatal cocaine (PCOC) treatment. We have shown that PCOC treatment results in augmented D1-induced cyclic AMP (cAMP) and cocaine-induced immediate-early gene expression in the striatum of adult mice. In this study we further examined basal as well as cocaine or D1-induced activation of a set of molecules known to be mediators of neuronal plasticity following psychostimulant treatment, with emphasis in the dorsal striatum (Str) and nucleus accumbens (NAc) of adult mice exposed to cocaine in utero. Basally, in the Str of PCOC treated mice there were significantly higher levels of (1) CREB and Ser133 P-CREB (2) Thr34 P-DARPP-32 and (3) GluA1 and Ser 845 P-GluA1 when compared to prenatal saline (PSAL) treated mice. In the NAc there were significantly higher basal levels of (1) CREB and Ser133 P-CREB, (2) Thr202/Tyr204 P-ERK2, and (3) Ser845 P-GluA1. Following acute administration of cocaine (15 mg/kg, i.p.) or D1 agonist (SKF 82958; 1 mg/kg, i.p.) there were significantly higher levels of Ser133 P-CREB, Thr34 P-DARPP-32, and Thr202/Tyr204 P-ERK2 in the Str that were evident in all animals tested. However, these cocaine-induced increases in phosphorylation were significantly augmented in PCOC mice compared to PSAL mice. In sharp contrast to the observations in the Str, in the NAc, acute administration of cocaine or D1 agonist significantly increased P-CREB and P-ERK2 in PSAL mice, a response that was not evident in PCOC mice. Examination of Ser 845 P-GluA1 revealed that cocaine or D1 agonist significantly increased levels in PSAL mice, but significantly decreased levels in the PCOC mice in both the Str and NAc. We also examined changes in brain-derived neurotrophic factor (BDNF). Our studies revealed significantly higher levels of the BDNF precursor, pro-BDNF, and one of its receptors, TrkB in the Str of PCOC mice compared to PSAL mice. These results suggest a persistent up-regulation of molecules critical to D1 and BDNF signaling in the Str of adult mice exposed to cocaine in utero. These molecular adaptations may underlie components of the behavioral deficits evident in exposed animals and a subset of exposed humans, and may represent a therapeutic target for ameliorating aspects of the PCOC-induced phenotype.

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.

Prenatal Cocaine Exposure and Motor Performance at 4 Months

OBJECTIVE

The relation between prenatal cocaine exposure and quality of movement was studied at 4 mo using the Posture and Fine Motor Assessment of Infants (PFMAI-I).

METHOD

Posture and fine motor scores of 4-month-old infants exposed to cocaine in utero (n = 370) were compared with an unexposed group (n = 533) within the context of gestational age, medical and demographic characteristics, and level of prenatal substance exposure using the PFMAI-I.

RESULTS

Infants prenatally exposed to cocaine had significantly lower posture scores than infants in the unexposed group. There was no main effect of cocaine exposure on fine motor scores; however, there were independent effects of gestational age at birth on both posture and fine motor scores at 4-mo corrected age.

CONCLUSION

These findings demonstrate independent contributions of prenatal cocaine exposure and prematurity to risk of motor delay and support the validity of the PFMAI-I as a measure of motor competence in early infancy.

Motor and cognitive outcomes through three years of age in children exposed to prenatal methamphetamine

BACKGROUND

Methamphetamine (MA) use among pregnant women is an increasing problem in the United States. The impact of prenatal MA exposure on development in childhood is unknown.

OBJECTIVE

To examine the effects of prenatal MA exposure on motor and cognitive development in children at 1, 2, and 3 years of age.

DESIGN/METHODS

IDEAL enrolled 412 mother-infant pairs at four sites (Tulsa OK, Des Moines IA, Los Angeles CA, and Honolulu HI). MA subjects (n=204) were identified by self report or GC/MS confirmation of amphetamine and metabolites in infant meconium. Comparison subjects (n=208) were matched (race, birth weight, maternal education, and type of insurance), denied amphetamine use, and had a negative meconium screen. Both groups included prenatal alcohol, tobacco and marijuana use, but excluded use of opiates, lysergic acid diethylamide, phencyclidine or cocaine only. The Peabody Developmental Motor Scales (PDMS-2) were administered to the infants at the 1 and 3 year visits. This analysis includes a subsample (n=350) of the IDEAL study with completed 1 and/or 3 year visits (n=330 and 281, respectively). At each annual visit we also conducted the Bayley Scales of Infant Development (BSID-II) as a general evaluation of mental and motor development. The BSID-II analysis includes a subsample (n=356) of the IDEAL study with completed 1, 2, and/or 3 year visits (n=331, 288, and 278 respectively). GLM analysis conducted on the PDMS-2 and BSID-II examined the effects of MA exposure and heavy MA exposure (≥3 days of use/week), with and without covariates. Longitudinal analyses were used to examine the effects of MA exposure on changes in motor and cognitive performance over time.

RESULTS

Heavy MA exposure was associated with significantly lower grasping scores than some and no use at 1 year (P=0.018). In longitudinal analysis, lower grasping scores associated with any MA exposure and heavy exposure persisted to 3 years. There were no effects of MA exposure, including heavy exposure, on the Bayley Mental Development Index (MDI) or Psychomotor Development Index (PDI) at any or across age.

CONCLUSIONS

There were no differences in cognition as assessed by the BSID-II between the groups. There was a subtle MA exposure effect on fine motor performance at 1 year with the poorest performance observed in the most heavily exposed children. By 3 years, no differences in fine motor performance were observed. These findings suggest MA exposure has modest motor effects at 1 year that are mostly resolved by 3 years.

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.

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 drug exposure: infant and toddler outcomes

This manuscript provides an overview of the current scientific literature on the impact of maternal drug use, specifically opioids and cocaine, during pregnancy on the acute and long-term outcomes of infants and toddlers from birth through age 3 years. Emphasis with regard to opioids is placed on heroin and opioid substitutes used to treat opioid addiction, including methadone, which has long been regarded as the standard of care in pregnancy, and buprenorphine, which is increasingly being investigated and prescribed as an alternative to methadone. Controlled studies comparing methadone at high and low doses, as well as those comparing methadone with buprenorphine, are highlighted and the diagnosis and management of neonatal abstinence syndrome is discussed. Over the past two decades, attention of the scientific and lay communities has also been focused on the potential adverse effects of cocaine and crack cocaine, especially during the height of the cocaine epidemic in the United States. Herein, the findings are summarized from prospective studies comparing cocaine-exposed with non-cocaine-exposed infants and toddlers with respect to anthropometric growth, infant neurobehavior, visual and auditory function, and cognitive, motor, and language development. The potentially stigmatizing label of the so-called "crack baby" preceded the evidence now accumulating from well-designed prospective investigations that have revealed less severe sequelae in the majority of prenatally exposed infants than originally anticipated. In contrast to opioids, which may produce neonatal abstinence syndrome and infant neurobehavioral deficits, prenatal cocaine exposure appears to be associated with what has been described as statistically significant but subtle decrements in neurobehavioral, cognitive, and language function, especially when viewed in the context of other exposures and the caregiving environment which may mediate or moderate the effects. Whether these early findings may herald more significant learning and behavioral problems during school-age and adolescence when the child is inevitably confronted with increasing social and academic challenges is the subject of ongoing longitudinal research.

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.

External pressure, motivation, and treatment outcome among pregnant substance-using women

The weight of evidence suggests that legal pressure to enter treatment facilitates retention. However, the extent to which such mandates (a) influence actual levels of substance use, or (b) also facilitate retention among pregnant women, is unclear. Associations between external pressure-defined as self-reported pressure to attend treatment under threat of incarceration, loss of child custody, and/or loss of subsidized housing--and the key outcomes of retention and substance use were therefore examined in a sample of 200 pregnant women receiving community-based substance abuse treatment. The role of external pressure was examined in a series of Cox and GEE regressions, which suggested that external pressure as measured at baseline was associated with decreased risk of dropout (Hazard Ratio=.47, p=.001) and fewer drug-positive urine tests throughout treatment and 12-week follow-up (OR=.48, p=.03). These differences did not appear to be the result of baseline differences between coerced and non-coerced participants in education, legal history, the presence or absence of a substance use disorder, employment, or motivation. The present findings extend the larger literature on external pressure by demonstrating effects on drug use as well as on retention, and among pregnant women.

Infant neurobehavioral dysregulation: behavior problems in children with prenatal substance exposure

OBJECTIVE

The objective of this study was to test a developmental model of neurobehavioral dysregulation relating prenatal substance exposure to behavior problems at age 7.

METHODS

The sample included 360 cocaine-exposed and 480 unexposed children from lower to lower middle class families of which 78% were black. Structural equation modeling was used to test models whereby prenatal exposure to cocaine and other substances would result in neurobehavioral dysregulation in infancy, which would predict externalizing and internalizing behavior problems in early childhood. Structural equation models were developed for individual and combined parent and teacher report for externalizing, internalizing, and total problem scores on the Child Behavior Checklist.

RESULTS

The goodness-of-fit statistics indicated that all of the models met criteria for adequate fit with 7 of the 9 models explaining 18% to 60% of the variance in behavior problems at age 7. The paths in the models indicate that there are direct effects of prenatal substance exposure on 7-year behavior problems as well as indirect effects, including neurobehavioral dysregulation.

CONCLUSIONS

Prenatal substance exposure affects behavior problems at age 7 through 2 mechanisms. The direct pathway is consistent with a teratogenic effect. Indirect pathways suggest cascading effects whereby prenatal substance exposure results in neurobehavioral dysregulation manifesting as deviations in later behavioral expression. Developmental models provide an understanding of pathways that describe how prenatal substance exposure affects child outcome and have significant implications for early identification and prevention.

Fetal effects of psychoactive drugs

Psychoactive drug use by pregnant women has the potential to effect fetal development; the effects are often thought to be drug-specific and gestational age dependent. This article describes the effects of three drugs with similar molecular targets that involve monoaminergic transmitter systems: cocaine, methamphetamine, and selective serotonin re-uptake inhibitors (SSRIs) used to treat maternal depression during pregnancy. We propose a possible common epigenetic mechanism for their potential effects on the developing child. We suggest that exposure to these substances acts as a stressor that affects fetal programming, disrupts fetal placental monoamine transporter expression and alters neuroendocrine and neurotransmitter system development. We also discuss neurobehavioral techniques that may be useful in the early detection of the effects of in utero drug exposure.

Neuroimaging of children following prenatal drug exposure

Recent advances in MR-based brain imaging methods have provided unprecedented capabilities to visualize the brain. Application of these methods has allowed identification of brain structures and patterns of functional activation altered in offspring of mothers who used licit (e.g., alcohol and tobacco) and illicit (e.g., cocaine, methamphetamine, and marijuana) drugs during pregnancy. Here we review that literature, which though somewhat limited by the complexities of separating the specific effects of each drug from other confounding variables, points to sets of interconnected brain structures as being altered following prenatal exposure to drugs of abuse. In particular, dopamine-rich cortical (e.g., frontal cortex) and subcortical (e.g., basal ganglia) fetal brain structures show evidence of vulnerability to intrauterine drug exposure suggesting that during brain development drugs of abuse share a specific profile of developmental neurotoxicity. Such brain malformations may shed light on mechanisms underlying prenatal drug-induced brain injury, may serve as bio-markers of significant intrauterine drug exposure, and may additionally be predictors of subsequent neuro-developmental compromise. Wider clinical use of these research-based non-invasive methods will allow for improved diagnosis and allocation of therapeutic resources for affected infants, children, and young adults.

Functional MRI and response inhibition in children exposed to cocaine in utero. Preliminary findings

This study investigated the potential long-term effects of cocaine exposure on brain functioning using fMRI in school-aged children. The sample included 12 children with prenatal cocaine exposure and 12 non-exposed children (8-9 years old). Groups did not differ on IQ, socioeconomic status, or perinatal risk factors. A response inhibition task was administered during an fMRI scan using a 1.5-T MRI system. Task performance did not differentiate groups, but groups were differentiated by patterns of task-related brain activity. Cocaine-exposed children showed greater activation in the right inferior frontal cortex and caudate during response inhibition, whereas non-exposed children showed greater activations in temporal and occipital regions. These preliminary findings suggest that prenatal cocaine may affect the development of brain systems involved in the regulation of attention and response inhibition.

Biobehavioral Outcomes in Adolescents and Young Adults Prenatally Exposed to Cocaine: Evidence From Animal Models

Cocaine has been a popular illicit drug among drug-using pregnant women over the last three decades. Prenatal cocaine exposure (PCE) has significant effects on children's development throughout early childhood. Very few human studies, however, report the effects of PCE on adolescent or early-adult development. As knowledge about early childhood effects in human children was informed by animal studies, this review considers the effects of PCE on behavioral outcomes in adolescent and young adult animals and provides potential guidance for research in human children. Animal models prenatally exposed to cocaine manifest play deficits, decreased social interaction, and increased aggression during competition in adolescence and young adulthood. Altered behavioral adaptation after stress exposure, including hormonal response change, is also evident. Attention deficits are reported in adult offspring with PCE, not only in a novel environment, but also in a final task session, indicating effects of PCE on transition and maintenance of attention. Animal studies support that PCE effects may extend beyond early childhood and continue to adolescence and adulthood. Additionally, some studies highlight that behavioral changes in offspring with PCE born without teratogenesis remain latent and reveal themselves during adulthood when animals are under stress conditions. Based on the evidence from animal models, well-designed human studies are needed to elucidate the effects of PCE on older human children. Research models that combine behavioral measures with stressful challenges may hold potential in discerning a longer term influence of PCE.

Treatment of substance abuse during pregnancy

Treatment programs for women who use drugs during pregnancy have developed out of a backdrop of punitive policies and the psychosocial complexities of this population, which include psychological comorbidities and consideration of the needs of their children. In this literature review, we examine evidence-based approaches to treatment for these women and some promising newer initiatives. We also discuss limitations of this research and issues that need to be addressed. The increasing understanding and acceptance of substance abuse as a treatable mental health disorder brings renewed optimism to this field.

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.

Effects of prenatal cocaine exposure on special education in school-aged children

OBJECTIVE

The objective of this study was to evaluate the effects of prenatal cocaine exposure on special education at age 7 with adjustment for covariates.

METHODS

As part of the prospective, longitudinal, multisite study of children with prenatal cocaine exposure (Maternal Lifestyle Study), school records were reviewed for 943 children at 7 years to determine involvement in special education outcomes: (1) individualized education plan; (2) special education conditions; (3) support services; (4) special education classes; and (5) speech and language services. Logistic regression was used to examine the effect of prenatal cocaine exposure on these outcomes with environmental, maternal, and infant medical variables as covariates, as well as with and without low child IQ.

RESULTS

Complete data for each analysis model were available for 737 to 916 children. When controlling for covariates including low child IQ, prenatal cocaine exposure had a significant effect on individualized education plan. When low child IQ was not included in the model, prenatal cocaine exposure had a significant effect on support services. Male gender, low birth weight, white race, and low child IQ also predicted individualized education plan. Low birth weight and low child IQ were significant in all models. White race was also significant in speech and language services. Other covariate effects were model specific. When included in the models, low child IQ accounted for more of the variance and changed the significance of other covariates.

CONCLUSIONS

Prenatal cocaine exposure increased the likelihood of receiving an individualized education plan and support services, with adjustment for covariates. Low birth weight and low child IQ increased the likelihood of all outcomes. The finding that white children were more likely to get an individualized education plan and speech and language services could indicate a greater advantage in getting educational resources for this population.

Augmented D1 dopamine receptor signaling and immediate-early gene induction in adult striatum after prenatal cocaine

BACKGROUND

Prenatal exposure to cocaine can impede normal brain development, triggering a range of neuroanatomical and behavioral anomalies that are evident throughout life. Mouse models have been especially helpful in delineating neuro-teratogenic consequences after prenatal exposure to cocaine. The present study employed a mouse model to investigate alterations in D(1) dopamine receptor signaling and downstream immediate-early gene induction in the striatum of mice exposed to cocaine in utero.

METHODS

Basal, forskolin-, and D(1) receptor agonist-induced cyclic adenosine monophosphate (cAMP) levels were measured ex vivo in the adult male striatum in mice exposed to cocaine in utero. Further studies assessed cocaine-induced zif 268 and homer 1 expression in the striatum of juvenile (P15), adolescent (P36), and adult (P60) male mice.

RESULTS

The D(1) dopamine receptor agonist SKF82958 induced significantly higher levels of cAMP in adult male mice treated with cocaine in utero compared with saline control subjects. No effects of the prenatal treatment were found for cAMP formation induced by forskolin. After an acute cocaine challenge (15 mg/kg, IP), these mice showed greater induction of zif 268 and homer 1, an effect that was most robust in the medial part of the mid-level striatum and became more pronounced with increasing age.

CONCLUSIONS

Together these findings indicate abnormally enhanced D(1) receptor signal transduction in adult mice after prenatal cocaine exposure. Such changes in dopamine receptor signaling might underlie aspects of long-lasting neuro-teratogenic effects evident in some humans after in utero exposure to cocaine and identify the striatum as one target potentially vulnerable to gestational cocaine exposure.

Parental methamphetamine abuse and children

Methamphetamine has alluring properties, such as the ability to promote weight loss and wakefulness, and because of its low price and ease of synthesis, methamphetamine abuse is now a nationwide problem in the United States. Unfortunately, the scope of the problem extends beyond adult users to the children of parents who are users. As methamphetamine abuse increases, the consequences of the epidemic pose major health and child welfare concerns. This article describes methamphetamine abuse and the long-term consequences of use, as well as specific nursing interventions to mitigate its effects.

Illicit drug use and neonatal outcomes: a critical review

Although the neonatal consequences of tobacco and alcohol exposure are well established, the evidence related to prenatal illicit drug use is less consistent despite prevalent views to the contrary. The many social, psychosocial, behavioral, and biomedical risk factors for adverse birth outcomes associated with illicit drug use complicate the evaluation of neonatal effects. Placing emphasis on recent research, this review summarizes the epidemiologic literature on the neonatal impact of marijuana, opiate, and cocaine use. Of these drugs, cocaine use is most consistently related to fetal growth decrements and dose-response effects have been observed. However, studies to date have largely failed to control for associated social, psychosocial, and contextual factors. Additional recommendations for future research are provided. It is likely that interventions will need to address the factors surrounding drug use to greatly improve neonatal outcomes (e.g., social circumstances, poor nutrition, stress, infections).