Prenatal exposure to antidepressants and depressed maternal mood alter trajectory of infant speech perception

Sex-dependent effects of maternal corticosterone and SSRI treatment on hippocampal neurogenesis across development

Background

Postpartum depression affects approximately 15% of mothers and represents a form of early life adversity for developing offspring. Postpartum depression can be treated with prescription antidepressants like fluoxetine (FLX). However, FLX can remain active in breast milk, raising concerns about the consequences of neonatal FLX exposure. The hippocampus is highly sensitive to developmental stress, and males and females respond differently to stress at many endpoints, including hippocampal plasticity. However, it is unclear how developmental exposure to FLX alters the trajectory of hippocampal development. The goal of this study was to examine the long-term effects of maternal postpartum corticosterone (CORT, a model of postpartum depression) and concurrent FLX on hippocampal neurogenesis in male and female offspring.

Methods

Female Sprague-Dawley rat dams were treated daily with either CORT or oil and FLX or saline from postpartum days 2–23. Offspring were perfused on postnatal day 31 (pre-adolescent), postnatal day 42 (adolescent), and postnatal day 69 (adult). Tissue was processed for doublecortin (DCX), an endogenous marker of immature neurons, in the dorsal and ventral hippocampus.

Results

Maternal postpartum CORT reduced density of DCX-expressing cells in the dorsal hippocampus of pre-adolescent males and increased it in adolescent males, suggesting that postpartum CORT exposure disrupted the typical progression of the density of DCX-expressing cells. Further, among offspring of oil-treated dams, pre-adolescent males had greater density of DCX-expressing cells than pre-adolescent females, and maternal postpartum CORT prevented this sex difference. In pre-adolescent females, maternal postpartum FLX decreased the density of DCX-expressing cells in the dorsal hippocampus compared to saline. As expected, maternal CORT reduced the density of DCX-expressing cells in adult female, but not male, offspring. The combination of maternal postpartum CORT/FLX diminished density of DCX-expressing cells in dorsal hippocampus regardless of sex or age.

Conclusions

These findings reveal how modeling treatment of postpartum depression with FLX alters hippocampal neurogenesis in developing offspring differently depending on sex, predominantly in the dorsal dentate gyrus and earlier in life.

Does maternal mental well-being in pregnancy impact the early human epigenome?

There is considerable interest in the potential nongenetic transmission of a suite of mental health conditions across generations, with epigenetics emerging as a candidate mediator of such effects. This review summarizes findings from 22 studies measuring candidate gene DNA methylation and seven epigenome-wide association studies of offspring epigenetic profile in women with adverse mental wellbeing measures (stress, depression or anxiety) in pregnancy. Despite some compelling evidence to suggest an association, there is a lack of reproducible findings, potentially linked to a number of limitations to this research and the field more broadly. Large cohorts with well characterized exposures across pregnancy are now needed. There is exciting potential that epigenetics may help explain some of the link between maternal wellbeing and child health outcomes, thereby informing novel interventions, but future studies must address current limitations to advance translational knowledge in this area.

Articulating What Infants Attune to in Native Speech

To become language users, infants must embrace the integrality of speech perception and production. That they do so, and quite rapidly, is implied by the native-language attunement they achieve in each domain by 6-12 months. Yet research has most often addressed one or the other domain, rarely how they interrelate. Moreover, mainstream assumptions that perception relies on acoustic patterns whereas production involves motor patterns entail that the infant would have to translate incommensurable information to grasp the perception-production relationship. We posit the more parsimonious view that both domains depend on commensurate articulatory information. Our proposed framework combines principles of the Perceptual Assimilation Model (PAM) and Articulatory Phonology (AP). According to PAM, infants attune to articulatory information in native speech and detect similarities of nonnative phones to native articulatory patterns. The AP premise that gestures of the speech organs are the basic elements of phonology offers articulatory similarity metrics while satisfying the requirement that phonological information be discrete and contrastive: (a) distinct articulatory organs produce vocal tract constrictions and (b) phonological contrasts recruit different articulators and/or constrictions of a given articulator that differ in degree or location. Various lines of research suggest young children perceive articulatory information, which guides their productions: discrimination of between- versus within-organ contrasts, simulations of attunement to language-specific articulatory distributions, multimodal speech perception, oral/vocal imitation, and perceptual effects of articulator activation or suppression. We conclude that articulatory gesture information serves as the foundation for developmental integrality of speech perception and production.

Prenatal exposure to antidepressants and risk of epilepsy in childhood

PURPOSE

This study aimed to estimate the association between prenatal exposure to antidepressants and risk of epilepsy in childhood, taking maternal depression into account.

METHODS

We conducted a population-based cohort study including all Danish singletons born alive between 1997 and 2008 (n = 734 237). Information on antidepressant medication and diagnosis of depression and epilepsy was obtained from Danish National Registers. The exposed group comprised children of mothers who used antidepressants from 30 days before pregnancy until the date of birth. The reference group comprised children of mothers who used no antidepressants from 6 months before pregnancy to birth. We estimated the hazard ratios (HR) of epilepsy and 95% confidence intervals (CI) using Cox proportional hazard models.

RESULTS

We identified 12 438 (1.7%) children exposed to antidepressants during pregnancy (including 30 days before pregnancy) and 5829 (0.8%) children diagnosed with epilepsy in the follow-up time (mean: 6.7 years). Children exposed to antidepressants during pregnancy had a 27% higher risk of epilepsy (aHR: 1.27; 95%CI: 1.05-1.54) than children in the reference group. The estimate of this association was 1.71 (95%CI: 1.10-2.66) if their mothers also had a registry-based hospital diagnosis of depression in the 6 months before pregnancy or during pregnancy and 1.14 (95%CI: 0.91-1.43) if their mothers had no registry-based hospital diagnosis of depression. Children of mothers who used antidepressants from 2 to 6 months before pregnancy (but not during pregnancy) had an increased risk of epilepsy (aHR: 1.36; 95%CI: 1.07-1.73).

CONCLUSIONS

Antidepressant use during pregnancy was associated with a higher risk of epilepsy among children whose mothers had also a registry-based hospital diagnosis of depression during pregnancy. Copyright © 2016 John Wiley & Sons, Ltd.

Of rodents and humans: A comparative review of the neurobehavioral effects of early life SSRI exposure in preclinical and clinical research

Selective serotonin reuptake inhibitors (SSRIs) have been a mainstay pharmacological treatment for women experiencing depression during pregnancy and postpartum for the past 25 years. SSRIs act via blockade of the presynaptic serotonin transporter and result in a transient increase in synaptic serotonin. Long-lasting changes in cellular function such as serotonergic transmission, neurogenesis, and epigenetics, are thought to underlie the therapeutic benefits of SSRIs. In recent years, though, growing evidence in clinical and preclinical settings indicate that offspring exposed to SSRIs in utero or as neonates exhibit long-lasting behavioral adaptions. Clinically, children exposed to SSRIs in early life exhibit increased internalizing behavior reduced social behavior, and increased risk for depression in adolescence. Similarly, rodents exposed to SSRIs perinatally exhibit increased traits of anxiety- or depression-like behavior. Furthermore, certain individuals appear to be more susceptible to early life SSRI exposure than others, suggesting that perinatal SSRI exposure may pose greater risks for negative outcome within certain populations. Although SSRIs trigger a number of intracellular processes that likely contribute to their therapeutic effects, early life antidepressant exposure during critical neurodevelopmental periods may elicit lasting negative effects in offspring. In this review, we cover the basic development and structure of the serotonin system, how the system is affected by early life SSRI exposure, and the behavioral outcomes of perinatal SSRI exposure in both clinical and preclinical settings. We review recent evidence indicating that perinatal SSRI exposure perturbs the developing limbic system, including altered serotonergic transmission, neurogenesis, and epigenetic processes in the hippocampus, which may contribute to behavioral domains (e.g., sociability, cognition, anxiety, and behavioral despair) that are affected by perinatal SSRI treatment. Identifying the molecular mechanisms that underlie the deleterious behavioral effects of perinatal SSRI exposure may highlight biological mechanisms in the etiology of mood disorders. Moreover, because recent studies suggest that certain individuals may be more susceptible to the negative consequences of early life SSRI exposure than others, understanding mechanisms that drive such susceptibility could lead to individualized treatment strategies for depressed women who are or plan to become pregnant.

Maternal Pharmacokinetics and Fetal Disposition of (±)-Citalopram during Mouse Pregnancy

While selective-serotonin reuptake inhibitor (SSRI) antidepressants are commonly prescribed in the treatment of depression, their use during pregnancy leads to fetal drug exposures. According to recent reports, such exposures could affect fetal development and long-term offspring health. A central question is how pregnancy-induced physical and physiological changes in mothers, fetuses, and the placenta influence fetal SSRI exposures during gestation. In this study, we examined the effects of gestational stage on the maternal pharmacokinetics and fetal disposition of the SSRI (±)-citalopram (CIT) in a mouse model. We determined the maternal and fetal CIT serum concentration-time profiles following acute maternal administration on gestational days (GD)14 and GD18, as well as the fetal brain drug disposition. The results show that pregnancy affects the pharmacokinetics of CIT and that maternal drug clearance increases as gestation progresses. The data further show that CIT and its primary metabolite desmethylcitalopram (DCIT) readily cross the placenta into the fetal compartment, and fetal exposure to CIT exceeds that of the mother during gestation 2 h after maternal administration. Enzymatic activity assays revealed that fetal drug metabolic capacity develops in late gestation, resulting in elevated circulating and brain concentrations of DCIT at embryonic day (E)18. Fetal exposure to the SSRI CIT in murine pregnancy is therefore influenced by both maternal gestational stage and embryonic development, suggesting potential time-dependent effects on fetal brain development.

Neural Language Processing in Adolescent First-Language Learners: Longitudinal Case Studies in American Sign Language

One key question in neurolinguistics is the extent to which the neural processing system for language requires linguistic experience during early life to develop fully. We conducted a longitudinal anatomically constrained magnetoencephalography (aMEG) analysis of lexico-semantic processing in 2 deaf adolescents who had no sustained language input until 14 years of age, when they became fully immersed in American Sign Language. After 2 to 3 years of language, the adolescents' neural responses to signed words were highly atypical, localizing mainly to right dorsal frontoparietal regions and often responding more strongly to semantically primed words (Ferjan Ramirez N, Leonard MK, Torres C, Hatrak M, Halgren E, Mayberry RI. 2014. Neural language processing in adolescent first-language learners. Cereb Cortex. 24 (10): 2772-2783). Here, we show that after an additional 15 months of language experience, the adolescents' neural responses remained atypical in terms of polarity. While their responses to less familiar signed words still showed atypical localization patterns, the localization of responses to highly familiar signed words became more concentrated in the left perisylvian language network. Our findings suggest that the timing of language experience affects the organization of neural language processing; however, even in adolescence, language representation in the human brain continues to evolve with experience.

A patient decision aid for antidepressant use in pregnancy: study protocol for a randomized controlled trial

Background

Many women with depression experience significant difficulty making a decision about whether or not to use antidepressant medication in pregnancy. Patient decision aids (PDAs) are tools that assist patients in making complex health decisions. PDAs can reduce decision-making difficulty and lead to better treatment outcomes. We describe the methods for a pilot randomized controlled trial of an interactive web-based PDA for women who are having difficulty deciding about antidepressant drug use in pregnancy.

Methods/Design

This is a pilot randomized controlled trial that aims to assess the feasibility of a larger, multi-center efficacy study. The PDA aims to help a woman: (1) understand why an antidepressant is being recommended, (2) be knowledgeable about potential benefits and risks of treatment and non-treatment with antidepressants, and (3) be clear about which benefits and risks are most important to her, with the goal of improving confidence in her decision-making. We include women aged 18 years or older who are: (1) planning a pregnancy or are pregnant (gestational age less than 30 weeks), (2) diagnosed with major depressive disorder, (3) deciding whether or not to use a selective serotonin reuptake inhibitor (SSRI) or serotonin norepinephrine reuptake inhibitor (SNRI) antidepressant in pregnancy, and (4) having at least moderate decision-making difficulty as per a Decisional Conflict Scale (DCS) Score ≥25. Participants are randomized to receive the PDA or an informational resource sheet via a secure website, and have access to the stated allocation until their final study follow-up. The primary outcomes of the pilot study are feasibility of recruitment and retention, acceptability of the intervention, and adherence to the trial protocol. The primary efficacy outcome is DCS score at 4 weeks post randomization, with secondary outcomes including depressive and anxiety symptoms.

Discussion

Our PDA represents a key opportunity to optimize the decision-making process for women around antidepressants in pregnancy, leading to effective decision-making and optimizing improved maternal and child outcomes related to depression in pregnancy. The electronic nature of the PDA will facilitate keeping it up-to-date, and allow for widespread dissemination after efficacy is demonstrated.

Trial registration

This trial is registered on ClinicalTrials.Gov under the identifier NCT02308592 (first registered: 2 December 2014).

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1233-4) contains supplementary material, which is available to authorized users.

Developmental changes in serotonin signaling: Implications for early brain function, behavior and adaptation

The neurotransmitter serotonin (5-HT) plays a central role in brain development, regulation of mood, stress reactivity and risk of psychiatric disorders, and thus alterations in 5-HT signaling early in life have critical implications for behavior and mental health across the life span. Drawing on preclinical and emerging human evidence this narrative review paper will examine three key aspects when considering the consequences of early life changes in 5-HT: (1) developmental origins of variations of 5-HT signaling; (2) influence of genetic and epigenetic factors; and (3) preclinical and clinical consequences of 5-HT-related changes associated with antidepressant exposure (SSRIs). The developmental consequences of altered prenatal 5-HT signaling varies greatly and outcomes depend on an ongoing interplay between biological (genetic/epigenetic variations) and environmental factors, both pre and postnatally. Emerging evidence suggests that variations in 5-HT signaling may increase sensitivity to risky home environments, but may also amplify a positive response to a nurturing environment. In this sense, factors that change central 5-HT levels may act as 'plasticity' rather than 'risk' factors associated with developmental vulnerability. Understanding the impact of early changes in 5-HT levels offers critical insights that might explain the variations in early typical brain development that underlies behavioral risk.

Preschool outcomes following prenatal serotonin reuptake inhibitor exposure: differences in language and behavior, but not cognitive function

OBJECTIVE

To test the hypothesis that prenatal exposure to serotonin reuptake inhibitors (SRIs) is associated with language and behavioral outcomes in preschool-aged children, while accounting for confounds such as concomitant exposures and maternal mental illness.

METHOD

An observational, prospective, longitudinal study of mental illness in pregnancy was conducted at a university-based women's mental health clinic (April 2010-November 2012). A sample of 178 mother-child dyads participated in a laboratory visit at preschool age (2.5-5.5 years). The majority of women (87%) received psychotropic medication during pregnancy. Psychiatric status (based on DSM-IV), other medication use, and substance use were serially assessed and tested as confounds. Primary outcome measures included standardized measures of expressive language and cognitive function and mother and alternate caregiver ratings of child behavior problems, including the Pervasive Developmental Disorders (PDD) subscale of the Child Behavior Checklist.

RESULTS

Linear regression analyses revealed that, after controlling for relevant covariates, expressive language scores from the Test of Early Language Development, 3rd edition, were negatively associated with prenatal SRI exposure (β = -0.15, t = -2.41), while the PDD behavioral problems subscales completed by alternate caregivers and mothers were positively associated with prenatal SRI exposure (β = 0.17, t = 2.01; β = 0.16, t = 2.00, respectively). Cognitive function, measured using the Differential Ability Scales, 2nd edition, was not associated with any medication exposures.

CONCLUSIONS

The current data suggest a small but significant association between prenatal SRI exposure and preschool outcomes, including expressive language and behavior problems. These data corroborate data from recent, population-based studies, although overall, published findings are mixed. Replication and identification of moderating risk factors are needed to understand potential clinical implications.

Delays in GABAergic interneuron development and behavioral inhibition after prenatal stress

Prenatal stress is associated with altered behavioral, cognitive, and psychiatric outcomes in offspring. Due to the importance of GABAergic systems in normal development and in psychiatric disorders, prenatal stress effects on these neurons have been investigated in animal models. Prenatal stress delays GABAergic progenitor migration, but the significance of these early developmental disruptions for the continued development of GABAergic cells in the juvenile brain is unclear. Here, we examined effects of prenatal stress on populations of GABAergic neurons in juvenile and adult medial frontal cortex (mFC) and hippocampus through stereological counting, gene expression, and relevant anxiety-like and social behaviors. Postnatally, the total GABAergic cell number that peaks in adolescence showed altered trajectories in mFC and hippocampus. Parvalbumin neuron proportion in juvenile brain was altered by prenatal stress, but parvalbumin gene expression showed no differences. In adult brain, parvalbumin neuron proportions were altered by prenatal stress with opposite gene expression changes. Adult prenatally stressed offspring showed a lack of social preference on a three-chambered task, increased anxiety-like behavior on the elevated plus maze, and reduced center time in an open field. Despite a lack of significant group differences in adult total GABAergic cell populations, performance of these tasks was correlated with GABAergic populations in mFC and hippocampus. In conclusion, prenatal stress resulted in a delay in GABAergic cell number and maturation of the parvalbumin subtype. Influences of prenatal stress on GABAergic populations during developmentally dynamic periods and during adulthood may be relevant to the anxiety-like behaviors that occur after prenatal stress. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 1078-1091, 2016.

Rethinking psychopharmacotherapy: The role of treatment context and brain plasticity in antidepressant and antipsychotic interventions

Emerging evidence indicates that treatment context profoundly affects psychopharmacological interventions. We review the evidence for the interaction between drug application and the context in which the drug is given both in human and animal research. We found evidence for this interaction in the placebo response in clinical trials, in our evolving knowledge of pharmacological and environmental effects on neural plasticity, and in animal studies analyzing environmental influences on psychotropic drug effects. Experimental placebo research has revealed neurobiological trajectories of mechanisms such as patients' treatment expectations and prior treatment experiences. Animal research confirmed that "enriched environments" support positive drug effects, while unfavorable environments (low sensory stimulation, low rates of social contacts) can even reverse the intended treatment outcome. Finally we provide recommendations for context conditions under which psychotropic drugs should be applied. Drug action should be steered by positive expectations, physical activity, and helpful social and physical environmental stimulation. Future drug trials should focus on fully controlling and optimizing such drug×environment interactions to improve trial sensitivity and treatment outcome.

Early-life serotonin dysregulation affects the migration and positioning of cortical interneuron subtypes

Early-life deficiency of the serotonin transporter (SERT) gives rise to a wide range of psychiatric-relevant phenotypes; however, the molecular and cellular targets of serotonin dyregulation during neural circuit formation remain to be identified. Interestingly, migrating cortical interneurons (INs) derived from the caudal ganglionic eminence (CGE) have been shown to be more responsive to serotonin-mediated signalling compared with INs derived from the medial ganglionic eminence (MGE). Here we investigated the impact of early-life SERT deficiency on the migration and positioning of CGE-derived cortical INs in SERT-ko mice and in mice exposed to the SERT inhibitor fluoxetine during the late embryonic period. Using confocal time-lapse imaging and microarray-based expression analysis we found that genetic and pharmacological SERT deficiency significantly increased the migratory speed of CGE-derived INs and affected transcriptional programmes regulating neuronal migration. Postnatal studies revealed that SERT deficiency altered the cortical laminar distribution of subtypes of CGE-derived INs but not MGE-derived INs. More specifically, we found that the distribution of vasointestinal peptide (VIP)-expressing INs in layer 2/3 was abnormal in both genetic and pharmacological SERT-deficiency models. Collectively, these data indicate that early-life SERT deficiency has an impact on the migration and molecular programmes of CGE-derived INs, thus leading to specific alterations in the positioning of VIP-expressing INs. These data add to the growing evidence that early-life serotonin dysregulation affects cortical microcircuit formation and contributes to the emergence of psychiatric-relevant phenotypes.

Prenatal chemical exposures and child language development

The goal of this review is to summarize the evidence that prenatal and/or early postnatal exposure to certain chemicals, both manmade (insulating materials, flame retardants, pesticides) and naturally occurring (e.g., lead, mercury), may be associated with delays or impairments in language development. We focus primarily on a subset of more extensively studied chemicals-polychlorinated biphenyls (PCBs), lead, and methyl mercury-for which a reasonable body of literature on neurodevelopmental outcomes is available. We also briefly summarize the smaller body of evidence for other chemicals including polybrominated diphenyl ether flame retardants (PBDEs) and organophosphate pesticides. Very few studies have used specific assessments of language development and function. Therefore, we included discussion of aspects of cognitive development such as overall intellectual functioning and verbal abilities that rely on language, as well as aspects of cognition such as verbal and auditory working memory that are critical underpinnings of language development. A high percentage of prospective birth cohort studies of PCBs, lead, and mercury have reported exposure-related reductions in overall IQ and/or verbal IQ that persist into middle or late childhood. Given these findings, it is important that clinicians and researchers in communication sciences and disorders are aware of the potential for environmental chemicals to impact language development.

LEARNING OUTCOMES

The goal of this review is to summarize the evidence that prenatal and/or early postnatal exposure to certain chemicals may be associated with delays or impairments in language development. Readers will gain an understanding of the literature suggesting that early exposure to polychlorinated biphenyls (PCBs), lead, and mercury may be associated with decrements in cognitive domains that depend on language or are critical for language development. We also briefly summarize the smaller body of evidence regarding polybrominated diphenyl ether flame retardants (PBDEs) and organophosphate pesticides. Very few studies of exposure to these chemicals have used specific assessments of language development; thus, further investigation is needed before changes in clinical practice can be suggested.

Causal effects on child language development: A review of studies in communication sciences and disorders

We reviewed recent studies published across key journals within the field of communication sciences and disorders (CSD) to survey what causal influences on child language development were being considered. Specifically, we reviewed a total of 2921 abstracts published within the following journals between 2003 and 2013: Language, Speech, and Hearing Services in Schools (LSHSS); American Journal of Speech-Language Pathology (AJSLP); Journal of Speech, Language, and Hearing Research (JSLHR); Journal of Communication Disorders (JCD); and the International Journal of Language and Communication Disorders (IJLCD). Of the 346 eligible articles that addressed causal factors on child language development across the five journals, 11% were categorized as Genetic (37/346), 83% (287/346) were categorized as Environmental, and 6% (22/346) were categorized as Mixed. The bulk of studies addressing environmental influences focused on therapist intervention (154/296=52%), family/caregiver linguistic input (65/296=22%), or family/caregiver qualities (39/296=13%). A more in-depth review of all eligible studies published in 2013 (n=34) revealed that family/caregiver qualities served as the most commonly controlled environmental factor (e.g., SES) and only 3 studies explicitly noted the possibility of gene-environment interplay. This review highlighted the need to expand the research base for the field of CSD to include a broader range of environmental influences on child language development (e.g., diet, toxin exposure, stress) and to consider more directly the complex and dynamic interplay between genetic and environmental effects.

LEARNING OUTCOMES

Readers will be able to highlight causal factors on child language development that have been studied over the past decade in CSD and recognize additional influences worthy of consideration. In addition, readers will become familiar with basic tenets of developmental systems theory, including the complex interplay between genetic and environmental factors that shapes child development.

Antidepressants, anxiolytics, and hypnotics in pregnancy and lactation

AIMS

Untreated perinatal depression and anxiety disorders are known to have significant negative impact on both maternal and fetal health. Dilemmas still remain regarding the use and safety of psychotropics in pregnant and lactating women suffering from perinatal depression and anxiety disorders. The aim of the current paper was to review the existing evidence base on the exposure and consequences of antidepressants, anxiolytics, and hypnotics in women during pregnancy and lactation and to make recommendations for clinical decision making in management of these cases.

MATERIALS AND METHODS

We undertook a bibliographic search of Medline/PubMed (1972 through 2014), Science Direct (1972 through 2014), Archives of Indian Journal of Psychiatry databases was done. References of retrieved articles, reference books, and dedicated websites were also checked.

RESULTS AND CONCLUSIONS

The existing evidence base is extensive in studying multiple outcomes of the antidepressant or anxiolytic exposure in neonates, and some of the findings appear conflicting. Selective serotonin reuptake inhibitors are the most researched antidepressants in pregnancy and lactation. The available literature is criticized mostly on the lack of rigorous well designed controlled studies as well as lacunae in the methodologies, interpretation of statistical information, knowledge transfer, and translation of information. Research in this area in the Indian context is strikingly scarce. Appropriate risk-benefit analysis of untreated mental illness versus medication exposure, tailor-made to each patient's past response and preference within in the context of the available evidence should guide clinical decision making.

Child developmental outcomes in preschool children following antidepressant exposure in pregnancy

OBJECTIVE

To examine child developmental outcomes in preschool-aged children exposed to antidepressant medication in pregnancy and compare their outcomes to children not exposed.

METHOD

A prospective case-controlled study of 20 children exposed to antidepressants in pregnancy and 21 unexposed controls was available from the Victorian Psychotropic Registry. Child development outcomes at 4 years of age were assessed using the Wechsler Preschool and Primary Scale of Intelligence, third edition; the Movement Assessment Battery for Children; Behaviour Rating Inventory of Executive Functioning-Preschool; and the Child Behavior Checklist (1.5-5 years). Maternal depression was assessed using the Beck Depression Inventory-II in pregnancy and at four time points across infancy and early childhood.

RESULTS

Children exposed to antidepressants in pregnancy had no statistically significant differences compared to unexposed children on any of the measures of child development undertaken. There was a trend to slightly lower scores in motor development with a small effect size for two scales of the Movement Assessment Battery for Children: balance - Cohen's d=0.36; aiming and catching - Cohen's d=0.34.

CONCLUSIONS

The finding of no effect on cognition and behaviour are consistent with other previous studies conducted with younger children. Likewise, the trend towards lower motor development is similar to earlier findings from this study and a number of other similar studies. Given this trend there is a need for future research that focuses on this area of development in older children using robust measures of motor development.

In utero exposure to selective serotonin reuptake inhibitors and risk for autism spectrum disorder

We investigated whether there is an association between increased risk for autism spectrum disorders (ASD) and selective serotonin reuptake inhibitors (SSRIs) used during pregnancy. This study used Denmark's health and population registers to obtain information regarding prescription drugs, ASD diagnosis, and health and socioeconomic status. There were 1.5 % of cases and 0.7 % of controls exposed to SSRIs during the pregnancy period, and higher effect estimates observed with longer use. We found evidence that in utero exposure to SSRIs increases a child's risk associated with ASD. These results, while adding to the limited knowledge on prenatal pharmacological exposures as potential ASD risk factors, need to be balanced against the benefits of indicated medication use by pregnant mothers.

Distinct effects of perinatal exposure to fluoxetine or methylmercury on parvalbumin and perineuronal nets, the markers of critical periods in brain development

The in utero exposure to common chemical stressors, environmental pollutant methylmercury and antidepressant fluoxetine, results in behavioral impairments persistent into adulthood. Modulation of critical periods in brain development may alter proper network formation and lastingly impair brain function. To investigate whether early-life stressors can modulate critical periods, we analyzed the development of parvalbumin (PV) and perineuronal nets (PNNs) in the dentate gyrus and CA1 area of the hippocampus and the basolateral amygdala in mice perinatally exposed to either fluoxetine or methylmercury. The number of PV and PNN neurons, and PV intensity, were analyzed by fluorescent immunohistochemistry at the postnatal ages P17 (ongoing critical period) and P24 (closing critical period). The exposure to fluoxetine did not affect the number of PV cells and PV intensity but decreased PNN formation around the cells at P17 and P24 in all tissues. In contrast, perinatal methylmercury inhibited the development of PV interneurons and PV expression at P17 only, but at P24 these parameters were restored. Methylmercury strongly increased PNN formation from P17 to P24 in the amygdala only. We suggest that perinatal fluoxetine and methylmercury might delay the closure and the onset, respectively, of the critical periods in the amygdala and hippocampus.

How animal models inform child and adolescent psychiatry

OBJECTIVE

Every available approach should be used to advance the field of child and adolescent psychiatry. Biological systems are important for the behavioral problems of children. Close examination of nonhuman animals and the biology and behavior that they share with humans is an approach that must be used to advance the clinical work of child psychiatry.

METHOD

We review here how model systems are used to contribute to significant insights into childhood psychiatric disorders. Model systems have not only demonstrated causality of risk factors for psychiatric pathophysiology, but have also allowed child psychiatrists to think in different ways about risks for psychiatric disorders and multiple levels that might be the basis of recovery and prevention.

RESULTS

We present examples of how animal systems are used to benefit child psychiatry, including through environmental, genetic, and acute biological manipulations. Animal model work has been essential in our current thinking about childhood disorders, including the importance of dose and timing of risk factors, specific features of risk factors that are significant, neurochemistry involved in brain functioning, molecular components of brain development, and the importance of cellular processes previously neglected in psychiatric theories.

CONCLUSION

Animal models have clear advantages and disadvantages that must be considered for these systems to be useful. Coupled with increasingly sophisticated methods for investigating human behavior and biology, animal model systems will continue to make essential contributions to our field.

Prenatal antidepressant exposure associated with CYP2E1 DNA methylation change in neonates

Some but not all neonates are affected by prenatal exposure to serotonin reuptake inhibitor antidepressants (SRI) and maternal mood disturbances. Distinguishing the impact of these 2 exposures is challenging and raises critical questions about whether pharmacological, genetic, or epigenetic factors can explain the spectrum of reported outcomes. Using unbiased DNA methylation array measurements followed by a detailed candidate gene approach, we examined whether prenatal SRI exposure was associated with neonatal DNA methylation changes and whether such changes were associated with differences in birth outcomes. Prenatal SRI exposure was first associated with increased DNA methylation status primarily at CYP2E1(β(Non-exposed) = 0.06, β(SRI-exposed) = 0.30, FDR = 0); however, this finding could not be distinguished from the potential impact of prenatal maternal depressed mood. Then, using pyrosequencing of CYP2E1 regulatory regions in an expanded cohort, higher DNA methylation status--both the mean across 16 CpG sites (P < 0.01) and at each specific CpG site (P < 0.05)--was associated with exposure to lower 3rd trimester maternal depressed mood symptoms only in the SRI-exposed neonates, indicating a maternal mood x SRI exposure interaction. In addition, higher DNA methylation levels at CpG2 (P = 0.04), CpG9 (P = 0.04) and CpG10 (P = 0.02), in the interrogated CYP2E1 region, were associated with increased birth weight independently of prenatal maternal mood, SRI drug exposure, or gestational age at birth. Prenatal SRI antidepressant exposure and maternal depressed mood were associated with altered neonatal CYP2E1 DNA methylation status, which, in turn, appeared to be associated with birth weight.

Depression during Pregnancy

A proportion of women enter pregnancy with active psychiatric symptoms or disorders, with or without concomitant psychotropic medication. Studies report that exposure to untreated depression and stress during pregnancy may have negative consequences for birth outcome and child development. Studies also report that antenatal exposure to antidepressant medications may have adverse consequences for birth outcome and child development. Antidepressant medication use during pregnancy leads to a small increased risk of miscarriage, a possible small increased risk of congenital cardiac malformations, a small increased risk of preterm birth, a small increased risk of persistent pulmonary hypertension of the newborn (PPHN), and transient neonatal symptoms in up to one-third of neonates. In addition, there is a possible increased risk of delayed motor development in children. Several recent systematic reviews and meta-analyses of the existent literature emphasize that there are minimal definitive conclusions to guide treatment recommendations. This review describes best practices for the management of depression in pregnancy, and it provides suggestions for future research.

Behavioral training reverses global cortical network dysfunction induced by perinatal antidepressant exposure

Abnormal cortical circuitry and function as well as distortions in the modulatory neurological processes controlling cortical plasticity have been argued to underlie the origin of autism. Here, we chemically distorted those processes using an antidepressant drug-exposure model to generate developmental neurological distortions like those characteristics expressed in autism, and then intensively trained altered young rodents to evaluate the potential for neuroplasticity-driven renormalization. We found that young rats that were injected s.c. with the antidepressant citalopram from postnatal d 1-10 displayed impaired neuronal repetition-rate following capacity in the primary auditory cortex (A1). With a focus on recovering grossly degraded auditory system processing in this model, we showed that targeted temporal processing deficits induced by early-life antidepressant exposure within the A1 were almost completely reversed through implementation of a simple behavioral training strategy (i.e., a modified go/no-go repetition-rate discrimination task). Degraded parvalbumin inhibitory GABAergic neurons and the fast inhibitory actions that they control were also renormalized by training. Importantly, antidepressant-induced degradation of serotonergic and dopaminergic neuromodulatory systems regulating cortical neuroplasticity was sharply reversed. These findings bear important implications for neuroplasticity-based therapeutics in autistic patients.

Critical periods in speech perception: new directions

A continuing debate in language acquisition research is whether there are critical periods (CPs) in development during which the system is most responsive to environmental input. Recent advances in neurobiology provide a mechanistic explanation of CPs, with the balance between excitatory and inhibitory processes establishing the onset and molecular brakes establishing the offset of windows of plasticity. In this article, we review the literature on human speech perception development within the context of this CP model, highlighting research that reveals the interplay of maturational and experiential influences at key junctures in development and presenting paradigmatic examples testing CP models in human subjects. We conclude with a discussion of how a mechanistic understanding of CP processes changes the nature of the debate: The question no longer is, "Are there CPs?" but rather what processes open them, keep them open, close them, and allow them to be reopened.

Gut microbiota, the immune system, and diet influence the neonatal gut-brain axis

The conceptual framework for a gut-brain axis has existed for decades. The Human Microbiome Project is responsible for establishing intestinal dysbiosis as a mediator of inflammatory bowel disease, obesity, and neurodevelopmental disorders in adults. Recent advances in metagenomics implicate gut microbiota and diet as key modulators of the bidirectional signaling pathways between the gut and brain that underlie neurodevelopmental and psychiatric disorders in adults. Evidence linking intestinal dysbiosis to neurodevelopmental disease outcomes in preterm infants is emerging. Recent clinical studies show that intestinal dysbiosis precedes late-onset neonatal sepsis and necrotizing enterocolitis in intensive care nurseries. Moreover, strong epidemiologic evidence links late-onset neonatal sepsis and necrotizing enterocolitis in long-term psychomotor disabilities of very-low-birth-weight infants. The notion of the gut-brain axis thereby supports that intestinal microbiota can indirectly harm the brain of preterm infants. In this review, we highlight the anatomy and physiology of the gut-brain axis and describe transmission of stress signals caused by immune-microbial dysfunction in the gut. These messengers initiate neurologic disease in preterm infants. Understanding neural and humoral signaling through the gut-brain axis will offer insight into therapeutic and dietary approaches that may improve the outcomes of very-low-birth-weight infants.

Serotonin-related pathways and developmental plasticity: relevance for psychiatric disorders

Risk for adult psychiatric disorders is partially determined by early-life alterations occurring during neural circuit formation and maturation. In this perspective, recent data show that the serotonin system regulates key cellular processes involved in the construction of cortical circuits. Translational data for rodents indicate that early-life serotonin dysregulation leads to a wide range of behavioral alterations, ranging from stress-related phenotypes to social deficits. Studies in humans have revealed that serotonin-related genetic variants interact with early-life stress to regulate stress-induced cortisol responsiveness and activate the neural circuits involved in mood and anxiety disorders. Emerging data demonstrate that early-life adversity induces epigenetic modifications in serotonin-related genes. Finally, recent findings reveal that selective serotonin reuptake inhibitors can reinstate juvenile-like forms of neural plasticity, thus allowing the erasure of long-lasting fear memories. These approaches are providing new insights on the biological mechanisms and clinical application of antidepressants.

Auditory reserve and the legacy of auditory experience

Musical training during childhood has been linked to more robust encoding of sound later in life. We take this as evidence for an auditory reserve: a mechanism by which individuals capitalize on earlier life experiences to promote auditory processing. We assert that early auditory experiences guide how the reserve develops and is maintained over the lifetime. Experiences that occur after childhood, or which are limited in nature, are theorized to affect the reserve, although their influence on sensory processing may be less long-lasting and may potentially fade over time if not repeated. This auditory reserve may help to explain individual differences in how individuals cope with auditory impoverishment or loss of sensorineural function.

Maternal use of antidepressant or anxiolytic medication during pregnancy and childhood neurodevelopmental outcomes: a systematic review

Antidepressant and anxiolytic medications are widely prescribed and used by pregnant women for acute and maintenance therapy. These drugs are able to pass the placental barrier, and may potentially influence fetal and brain development. It is possible that exposure to prenatal antidepressants or anxiolytic medication may disturb neurotransmitter systems in the brain and have long-lasting consequences on neurodevelopment in the offspring. As all medication during pregnancy may pose a certain risk to the developing fetus, the potential benefits of the medication must be weighed against the risks for both mother and her unborn child. Therefore, information to guide patients and physicians to make a well-balanced decision for the appropriate treatment during pregnancy is needed. In this systematic review, an overview of maternal use of antidepressant or anxiolytic medication during pregnancy and childhood neurodevelopmental outcomes is provided. Some studies indicate a relation between prenatal exposure to antidepressants and adverse neurodevelopmental outcomes such as delayed motor development/motor control, social difficulties, internalizing problems and autism, but cannot rule out confounding by indication. Overall, the results of the observational studies have been inconsistent, which makes translation of the findings into clinical recommendations difficult. More well-designed observational studies and also randomized controlled trials (e.g., maintenance treatment vs. cessation) are needed to move forward and provide a comprehensive evaluation of the risks and benefits of antidepressant and anxiolytic use during pregnancy.

Follow-up study of children whose mothers were treated with transcranial magnetic stimulation during pregnancy: preliminary results

OBJECTIVES

The purpose of this study is to determine the impact of repetitive transcranial stimulation (rTMS) treatment during pregnancy on neurodevelopment of children.

MATERIALS AND METHODS

Women who were treated with rTMS during pregnancy and delivered liveborn children between 2008 and 2013 were selected. A control group consisted of children whose mothers had a history of untreated depression during their pregnancy (N = 26). Early developmental characteristics of all the children in the study were evaluated, and their developmental levels were determined using the Ankara Developmental Screening Inventory.

RESULTS

The mean age of the children in the rTMS treatment group was 32.4 months (range 16-64 months), and that of the untreated group was 29.04 (range 14-63 months). Jaundice (N = 2) and febrile convulsion (N = 1) were the reported medical conditions in the children of the rTMS-treated group; jaundice (N = 3) and low birth weight (N = 1) were reported in the untreated group. In the rTMS group, mothers' perception of delay in language development was observed, but there were not any statistically significant differences in the prevalence rate compared with the untreated group (OR = 0.38; 95% CI 0.0860-1.6580).

CONCLUSIONS

Our results suggest that rTMS exposure during pregnancy is not associated with poorer cognitive or motor development outcomes in children aged 18-62 months. Although language development as reported by the mothers was found to be poorer than expected in the rTMS-treated group, the delay was found to be similar to the language delay observed in offspring of untreated mothers, as reported in previous studies of prenatal depression treated with selective serotonin reuptake inhibitors.

Balancing plasticity/stability across brain development

The potency of the environment to shape brain function changes dramatically across the lifespan. Neural circuits exhibit profound plasticity during early life and are later stabilized. A focus on the cellular and molecular bases of these developmental trajectories has begun to unravel mechanisms, which control the onset and closure of such critical periods. Two important concepts have emerged from the study of critical periods in the visual cortex: (1) excitatory-inhibitory circuit balance is a trigger; and (2) molecular "brakes" limit adult plasticity. The onset of the critical period is determined by the maturation of specific GABA circuits. Targeting these circuits using pharmacological or genetic approaches can trigger premature onset or induce a delay. These manipulations are so powerful that animals of identical chronological age may be at the peak, before, or past their plastic window. Thus, critical period timing per se is plastic. Conversely, one of the outcomes of normal development is to stabilize the neural networks initially sculpted by experience. Rather than being passively lost, the brain's intrinsic potential for plasticity is actively dampened. This is demonstrated by the late expression of brake-like factors, which reversibly limit excessive circuit rewiring beyond a critical period. Interestingly, many of these plasticity regulators are found in the extracellular milieu. Understanding why so many regulators exist, how they interact and, ultimately, how to lift them in noninvasive ways may hold the key to novel therapies and lifelong learning.

Antenatal depression and antidepressants during pregnancy: unraveling the complex interactions for the offspring

During pregnancy the risk for a woman to develop a depressive episode is as high as 20%. Antenatal depression is not harmless for the developing child as several changes, including neurodevelopmental alterations, have been reported. Sometimes it is unavoidable to treat a pregnant mother with antidepressants, especially when she is suicidal. Currently, selective serotonin reuptake inhibitors (SSRIs) are the pharmacological choice of antidepressant treatment. SSRIs do not cause gross teratogenic alterations and are generally considered safe for use in pregnancy. However, although SSRIs may relieve the maternal symptoms, they definitively cross the placenta partially influencing the neurodevelopment of the fetus. In this review an overview is given of the effects on the offspring of maternal antenatal depression and the putative neurodevelopmental effects of SSRI treatment during pregnancy. Although we primarily focus on human data, some animal data are discussed to describe possible mechanisms on how SSRIs are affecting underlying biological mechanisms associated with depression. In summary, maternal depression may have long-lasting effects on the offspring, whereas prenatal SSRI exposure also increases the risk for long-lasting effects. It remains to be determined whether the effects found after SSRI treatment in pregnant women are only due to the SSRI exposure or if the underlying depression is also contributing to these effects. The possibility of epigenetic alterations as one of the underlying mechanisms that is altered by SSRI exposure is discussed. However much more research in this area is needed to explain the exact role of epigenetic mechanisms in SSRI exposure during pregnancy.

Maternal depression and expressive communication in one-year-old infants

To separate effects of maternal depression on infant cognitive versus language development, 1-year-olds were assessed using the revised Bayley Scales of Infant and Toddler Development (BSID-III). Percentile scores on the Bayley Expressive Communication (EC) subscale were significantly negatively correlated with maternal self-report scores on the Beck Depression Inventory (BDI-II). However, mothers' BDI-II scores did not correlate with infant percentile scores on the general cognitive (COG) or receptive communication (RC) subscales. Boys had significantly lower percentile scores than girls on the RC and EC scales, but did not differ on the Cog scale. Gender and maternal depression did not significantly interact on any of the scales. These findings suggest problems with expressive communication precede, and may at least partially account for, apparent deficits in general cognitive development.

Beyond classical inheritance: the influence of maternal genotype upon child's brain morphology and behavior

Genetic variance has been associated with variations in brain morphology, cognition, behavior, and disease risk. One well studied example of how common genetic variance is associated with brain morphology is the serotonin transporter gene polymorphism within the promoter region (5-HTTLPR). Because serotonin is a key neurotrophic factor during brain development, genetically determined variations in serotonin activity during maturation, in particular during early prenatal development, may underlie the observed association. However, the intrauterine microenvironment is not only determined by the child's, but also the mother's genotype. Therefore, we hypothesized that maternal 5-HTTLPR genotype influences the child's brain development beyond direct inheritance. To test this hypothesis, we investigated 76 children who were all heterozygous for the 5-HTTLPR (sl) and who had mothers who were either homozygous for the long (ll) or the short allele (ss). Using MRI, we assessed brain morphology as a function of maternal genotype. Gray matter density of the somatosensory cortex was found to be greater in children of ss mothers compared with children of ll mothers. Behavioral assessment showed that fine motor task performance was altered in children of ll mothers and the degree of this behavioral effect correlated with somatosensory cortex density across individuals. Our findings provide initial evidence that maternal genotype can affect the child's phenotype beyond effects of classical inheritance. Our observation appears to be explained by intrauterine environmental differences or by differences in maternal behavior.

Loudness perception affected by early age hearing loss

Tinnitus and hyperacusis, commonly seen in adults, are also reported in children. Although clinical studies found children with tinnitus and hyperacusis often suffered from recurrent otitis media, there is no direct study on how temporary hearing loss in the early age affects the sound loudness perception. In this study, sound loudness changes in rats affected by perforation of the tympanic membranes (TM) have been studied using an operant conditioning based behavioral task. We detected significant increases of sound loudness and susceptibility to audiogenic seizures (AGS) in rats with bilateral TM damage at postnatal 16 days. As increase to sound sensitivity is commonly seen in hyperacusis and tinnitus patients, these results suggest that early age hearing loss is a high risk factor to induce tinnitus and hyperacusis in children. In the TM damaged rats, we also detected a reduced expression of GABA receptor δ and α6 subunits in the inferior colliculus (IC) compared to the controls. Treatment of vigabatrin (60 mg/kg/day, 7-14 days), an anti-seizure drug that inhibits the catabolism of GABA, not only blocked AGS, but also significantly attenuated the loudness response. Administration of vigabatrin following the early age TM damage could even prevent rats from developing AGS. These results suggest that TM damage at an early age may cause a permanent reduction of GABA tonic inhibition which is critical towards the maintenance of normal loudness processing of the IC. Increasing GABA concentration during the critical period may alleviate the impairment in the brain induced by early age hearing loss.

Early life programming as a target for prevention of child and adolescent mental disorders

This paper concerns future policy development and programs of research for the prevention of mental disorders based on research emerging from fetal and early life programming. The current review offers an overview of findings on pregnancy exposures such as maternal mental health, lifestyle factors, and potential teratogenic and neurotoxic exposures on child outcomes. Outcomes of interest are common child and adolescent mental disorders including hyperactive, behavioral and emotional disorders. This literature suggests that the preconception and perinatal periods offer important opportunities for the prevention of deleterious fetal exposures. As such, the perinatal period is a critical period where future mental health prevention efforts should be focused and prevention models developed. Interventions grounded in evidence-based recommendations for the perinatal period could take the form of public health, universal and more targeted interventions. If successful, such interventions are likely to have lifelong effects on (mental) health.

Health related quality of life in parents of children with speech and hearing impairment

OBJECTIVES

Hearing impairment and specific language disorder are two entities that seriously affect language acquisition in children and reduce their communication skills. These children require specific treatment and higher levels of care than healthy children. Their language abilities also strongly influence parent-child interactions. The purpose of our study was to evaluate the health-related quality of life (HRQOL) of the parents of hearing-impaired children and the parents of children with speech difficulties (specific language disorder).

METHODS

Our study subjects included 349 parents (182 mothers and 167 fathers) of preschool-aged children with receptive expressive language disorder and 131 parents (71 mothers and 60 fathers) of children with severe hearing impairment. A control group was composed of 146 parents (82 mothers and 64 fathers) of healthy children of the same age. HRQOL was assessed using the SF-36 questionnaire.

RESULTS

For all groups of parents, the mothers had poorer scores compared with the fathers, but large differences were apparent depending on the child's impairment. In the control group, the scores of the mothers were significantly lower than the fathers' scores in only two (of eight) health domains. In contrast, the scores were lower in three domains for the mothers of speech-impaired children and in six domains for the mothers of hearing-impaired children, representing the greatest difference between the parents. When compared with the control group, both the mothers and fathers of speech-impaired children scored significantly worse in five health domains. Fathers of hearing-impaired children scored significantly worse than controls in three health domains. The lowest scores, indicating the poorest HRQOL, were observed for mothers of hearing-impaired children, who obtained significantly lower scores than the control mothers in all health domains except the emotional role.

CONCLUSIONS

The parents of preschool-aged speech-and hearing-impaired children experience poorer HRQOL than parents of healthy children of the same age. Mothers of hearing-impaired children are especially affected, demonstrating a negative impact in almost all health domains.

Perceptual attunement in vowels: a meta-analysis

Although the majority of evidence on perceptual narrowing in speech sounds is based on consonants, most models of infant speech perception generalize these findings to vowels, assuming that vowel perception improves for vowel sounds that are present in the infant's native language within the first year of life, and deteriorates for non-native vowel sounds over the same period of time. The present meta-analysis contributes to assessing to what extent these descriptions are accurate in the first comprehensive quantitative meta-analysis of perceptual narrowing in infant vowel discrimination, including results from behavioral, electrophysiological, and neuroimaging methods applied to infants 0-14 months of age. An analysis of effect sizes for native and non-native vowel discrimination over the first year of life revealed that they changed with age in opposite directions, being significant by about 6 months of age.

Use of Psychotropic Medication during Pregnancy and the Postpartum Period

Women with active psychiatric disorders who become pregnant face treatment dilemmas. Although results from studies are inconsistent, small but significant, risks on birth outcomes occur with exposure to untreated disorders, as well as to psychotropic medications. Prenatal antidepressant medication exposure may increase the risk for spontaneous miscarriage, preterm birth, cardiac malformations, persistent pulmonary hypertension of the newborn and postnatal adaptation syndrome. The use of valproate is contraindicated during pregnancy due to teratogenicity and neurocognitive delay and deficits. This review of selected studies will highlight some of the current issues with the use of psychotropic medications during pregnancy and the postpartum period.

Prenatal serotonin reuptake inhibitor (SRI) antidepressant exposure and serotonin transporter promoter genotype (SLC6A4) influence executive functions at 6 years of age

Prenatal exposure to serotonin reuptake inhibitor (SRI) antidepressants and maternal depression may affect prefrontal cognitive skills (executive functions; EFs) including self-control, working memory and cognitive flexibility. We examined long-term effects of prenatal SRI exposure on EFs to determine whether effects are moderated by maternal mood and/or genetic variations in SLC6A4 (a gene that codes for the serotonin transporter [5-HTT] central to the regulation of synaptic serotonin levels and behavior). Children who were exposed to SRIs prenatally (SRI-exposed N = 26) and non-exposed (N = 38) were studied at age 6 years (M = 6.3; SD = 0.5) using the Hearts & Flowers task (H&F) to assess EFs. Maternal mood was measured during pregnancy (3rd trimester) and when the child was age 6 years (Hamilton Depression Scale). Parent reports of child behavior were also obtained (MacArthur Health & Behavior Questionnaire). Parents of prenatally SRI-exposed children reported fewer child externalizing and inattentive (ADHD) behaviors. Generalized estimate equation modeling showed a significant 3-way interaction between prenatal SRI exposure, SLC6A4 variant, and maternal mood at the 6-year time-point on H&F accuracy. For prenatally SRI-exposed children, regardless of maternal mood, the H&F accuracy of children with reduced 5HTT expression (a short [S] allele) remained stable. Even with increasing maternal depressive symptoms (though all below clinical threshold), EFs of children with at least one short allele were comparable to children with the same genotype whose mothers reported few if any depressive symptoms—in this sense they showed resilience. Children with two long (L) alleles were more sensitive to context. When their mothers had few depressive symptoms, LL children showed extremely good EF performance—better than any other group. When their mothers reported more depressive symptoms, LL children's EF performance was worse than that of any other group. In the face of a mother with a more depressed mood, EFs were best preserved in children prenatally exposed to SRIs and with at least one short SLC6A4 allele. Yet, prenatally-exposed LL children hold out promise of possibly superior EF if their mother's mood remains euthymic or improves.

Theta brain rhythms index perceptual narrowing in infant speech perception

The development of speech perception shows a dramatic transition between infancy and adulthood. Between 6 and 12 months, infants' initial ability to discriminate all phonetic units across the world's languages narrows-native discrimination increases while non-native discrimination shows a steep decline. We used magnetoencephalography (MEG) to examine whether brain oscillations in the theta band (4-8 Hz), reflecting increases in attention and cognitive effort, would provide a neural measure of the perceptual narrowing phenomenon in speech. Using an oddball paradigm, we varied speech stimuli in two dimensions, stimulus frequency (frequent vs. infrequent) and language (native vs. non-native speech syllables) and tested 6-month-old infants, 12-month-old infants, and adults. We hypothesized that 6-month-old infants would show increased relative theta power (RTP) for frequent syllables, regardless of their status as native or non-native syllables, reflecting young infants' attention and cognitive effort in response to highly frequent stimuli ("statistical learning"). In adults, we hypothesized increased RTP for non-native stimuli, regardless of their presentation frequency, reflecting increased cognitive effort for non-native phonetic categories. The 12-month-old infants were expected to show a pattern in transition, but one more similar to adults than to 6-month-old infants. The MEG brain rhythm results supported these hypotheses. We suggest that perceptual narrowing in speech perception is governed by an implicit learning process. This learning process involves an implicit shift in attention from frequent events (infants) to learned categories (adults). Theta brain oscillatory activity may provide an index of perceptual narrowing beyond speech, and would offer a test of whether the early speech learning process is governed by domain-general or domain-specific processes.

Serotonin homeostasis and serotonin receptors as actors of cortical construction: special attention to the 5-HT3A and 5-HT6 receptor subtypes

Cortical circuits control higher-order cognitive processes and their function is highly dependent on their structure that emerges during development. The construction of cortical circuits involves the coordinated interplay between different types of cellular processes such as proliferation, migration, and differentiation of neural and glial cell subtypes. Among the multiple factors that regulate the assembly of cortical circuits, 5-HT is an important developmental signal that impacts on a broad diversity of cellular processes. 5-HT is detected at the onset of embryonic telencephalic formation and a variety of serotonergic receptors are dynamically expressed in the embryonic developing cortex in a region and cell-type specific manner. Among these receptors, the ionotropic 5-HT3A receptor and the metabotropic 5-HT6 receptor have recently been identified as novel serotonergic targets regulating different aspects of cortical construction including neuronal migration and dendritic differentiation. In this review, we focus on the developmental impact of serotonergic systems on the construction of cortical circuits and discuss their potential role in programming risk for human psychiatric disorders.

Central nervous system effects of prenatal selective serotonin reuptake inhibitors: sensing the signal through the noise

RATIONALE

Women are increasingly prescribed selective serotonin reuptake inhibitors (SSRIs) during pregnancy, with potential implications for neurodevelopment. Whether prenatal SSRI exposure has an effect on neurodevelopment and behavior in the offspring is an important area of investigation.

OBJECTIVES

The aim of this paper was to review the existing preclinical and clinical literature of prenatal SSRI exposure on serotonin-related behaviors and markers in the offspring. The goal is to determine if there is a signal in the literature that could guide clinical care and/or inform research.

RESULTS

Preclinical studies (n = 4) showed SSRI exposure during development enhanced depression-like behavior. Half of rodent studies examining anxiety-like behavior (n = 13) noted adverse effects with SSRI exposure. A majority of studies of social behavior (n = 4) noted a decrease in sociability in SSRI exposed offspring. Human studies (n = 4) examining anxiety in the offspring showed no adverse effects of prenatal SSRI exposure. The outcome of one study suggested that children with autism were more likely to have a mother who was prescribed an SSRI during pregnancy.

CONCLUSIONS

Preclinical findings in rodents exposed to SSRIs during development point to an increase in depression- and anxiety-like behavior and alteration in social behaviors in the offspring, though both the methods used and the findings were not uniform. These data are not robust enough to discourage use of SSRIs during human pregnancy, particularly given the known adverse effects of maternal mental illness on pregnancy outcomes and infant neurodevelopment. Future research should focus on consistent animal models and prospective human studies with larger samples.