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

High Depressive Symptoms, Low Family Functioning, and Low Self-Efficacy in Mothers of Children With Autism Spectrum Disorder Compared to Two Control Groups

BACKGROUND

Parents of children with autism spectrum disorder (ASD) face unique challenges in raising their children, and they are at higher risk for depression compared to parents of children with typical development (TD) and other disabilities.

AIMS

(1) To compare prevalence of depressive symptoms among mothers of children with ASD (n = 101), Down syndrome (DS, n = 101), and TD (n = 43) and (2) to describe the relationships among depression, self-efficacy, and family functioning, and describe the mediating role of maternal child care self-efficacy between depressive symptoms and child behavior.

METHODS

In this cross-sectional study, mothers completed the Social Communication Questionnaire, Aberrant Behavior Checklist, Patient Health Questionnaire-9 (PHQ-9), Family Assessment Device General Functioning Scale, and Maternal Self-Efficacy Scale.

RESULTS

Mothers of children with ASD had significantly higher mean PHQ-9 scores (p < .001), higher proportion of positive depression screening (p < .001), and lower family functioning (p < .001). Better family functioning is associated with less depression, better self-efficacy, and less severe ASD symptoms and behaviors. Self-efficacy mediated the relationship between depression and child ASD symptoms, and problematic behavior.

CONCLUSIONS

The rates of reported history of depression and low family functioning in mothers of children with ASD are twice the rate in mothers of children with DS and TD. Maternal child care self-efficacy is protective against maternal depression, even in the presence of severe child problematic behaviors and ASD symptoms. Interventions that increase child care self-efficacy and family functioning may be helpful in addressing depression in mothers of children with ASD.

The State of Use and Utility of Negative Controls in Pharmacoepidemiologic Studies

Uses of real-world data in drug safety and effectiveness studies are often challenged by various sources of bias. We undertook a systematic search of the published literature through September 2020 to evaluate the state of use and utility of negative controls to address bias in pharmacoepidemiologic studies. Two reviewers independently evaluated study eligibility and abstracted data. Our search identified 184 eligible studies for inclusion. Cohort studies (115, 63%) and administrative data (114, 62%) were, respectively, the most common study design and data type used. Most studies used negative control outcomes (91, 50%), and for most studies the target source of bias was unmeasured confounding (93, 51%). We identified 4 utility domains of negative controls: 1) bias detection (149, 81%), 2) bias correction (16, 9%), 3) P-value calibration (8, 4%), and 4) performance assessment of different methods used in drug safety studies (31, 17%). The most popular methodologies used were the 95% confidence interval and P-value calibration. In addition, we identified 2 reference sets with structured steps to check the causality assumption of the negative control. While negative controls are powerful tools in bias detection, we found many studies lacked checking the underlying assumptions. This article is part of a Special Collection on Pharmacoepidemiology.

Environmental Influences on Individuals with Autistic Spectrum Disorders with Special Emphasis on Seasonality: An Overview

This paper offers an in-depth exploration of the intricate relationship between environmental factors and autism spectrum disorder (ASD), with a special emphasis on seasonality. It reviews existing research, providing a comprehensive summary of findings and highlighting the multifaceted dimensions of several environmental factors influencing the etiology of ASD. The discussion encompasses various elements, including birth months, maternal health, dietary choices, and vitamin D deficiency, delving into the intricate interplay of seasonality with environmental influences such as viral infections and solar radiation. The present study raises essential questions regarding the timing of environmental influences and the factors contributing to the rising prevalence of ASD. Ultimately, it underscores the need for future epidemiological research to incorporate more extensive investigations of environmental risk factors and employ advanced statistical analyses. This comprehensive overview contributes to a deeper understanding of how environmental factors, particularly seasonality, may be linked to the occurrence of ASD and its increasing prevalence, recognizing the multifaceted and diverse nature of these interactions.

Antidepressants in pregnancy: applying causal epidemiological methods to understand service-use outcomes in women and long-term neurodevelopmental outcomes in exposed children

Background

Antidepressants are commonly prescribed during pregnancy, despite a lack of evidence from randomised trials on the benefits or risks. Some studies have reported associations of antidepressants during pregnancy with adverse offspring neurodevelopment, but whether or not such associations are causal is unclear.

Objectives

To study the associations of antidepressants for depression in pregnancy with outcomes using multiple methods to strengthen causal inference.

Design

This was an observational cohort design using multiple methods to strengthen causal inference, including multivariable regression, propensity score matching, instrumental variable analysis, negative control exposures, comparison across indications and exposure discordant pregnancies analysis.

Setting

This took place in UK general practice.

Participants

Participants were pregnant women with depression.

Interventions

The interventions were initiation of antidepressants in pregnancy compared with no initiation, and continuation of antidepressants in pregnancy compared with discontinuation.

Main outcome measures

The maternal outcome measures were the use of primary care and secondary mental health services during pregnancy, and during four 6-month follow-up periods up to 24 months after pregnancy, and antidepressant prescription status 24 months following pregnancy. The child outcome measures were diagnosis of autism, diagnosis of attention deficit hyperactivity disorder and intellectual disability.

Data sources

UK Clinical Practice Research Datalink.

Results

Data on 80,103 pregnancies were used to study maternal primary care outcomes and were linked to 34,274 children with at least 4-year follow-up for neurodevelopmental outcomes. Women who initiated or continued antidepressants during pregnancy were more likely to have contact with primary and secondary health-care services during and after pregnancy and more likely to be prescribed an antidepressant 2 years following the end of pregnancy than women who did not initiate or continue antidepressants during pregnancy (odds ratioinitiation 2.16, 95% confidence interval 1.95 to 2.39; odds ratiocontinuation 2.40, 95% confidence interval 2.27 to 2.53). There was little evidence for any substantial association with autism (odds ratiomultivariableregression 1.10, 95% confidence interval 0.90 to 1.35; odds ratiopropensityscore 1.06, 95% confidence interval 0.84 to 1.32), attention deficit hyperactivity disorder (odds ratiomultivariableregression 1.02, 95% confidence interval 0.80 to 1.29; odds ratiopropensityscore 0.97, 95% confidence interval 0.75 to 1.25) or intellectual disability (odds ratiomultivariableregression 0.81, 95% confidence interval 0.55 to 1.19; odds ratiopropensityscore 0.89, 95% confidence interval 0.61 to 1.31) in children of women who continued antidepressants compared with those who discontinued antidepressants. There was inconsistent evidence of an association between initiation of antidepressants in pregnancy and diagnosis of autism in offspring (odds ratiomultivariableregression 1.23, 95% confidence interval 0.85 to 1.78; odds ratiopropensityscore 1.64, 95% confidence interval 1.01 to 2.66) but not attention deficit hyperactivity disorder or intellectual disability; however, but results were imprecise owing to smaller numbers.

Limitations

Several causal-inference analyses lacked precision owing to limited numbers. In addition, adherence to the prescribed treatment was not measured.

Conclusions

Women prescribed antidepressants during pregnancy had greater service use during and after pregnancy than those not prescribed antidepressants. The evidence against any substantial association with autism, attention deficit hyperactivity disorder or intellectual disability in the children of women who continued compared with those who discontinued antidepressants in pregnancy is reassuring. Potential association of initiation of antidepressants during pregnancy with offspring autism needs further investigation.

Future work

Further research on larger samples could increase the robustness and precision of these findings. These methods applied could be a template for future pharmaco-epidemiological investigation of other pregnancy-related prescribing safety concerns.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (15/80/19) and will be published in full in Health Technology Assessment; Vol. 27, No. 15. See the NIHR Journals Library website for further project information.

Prenatal SSRI Exposure Increases the Risk of Autism in Rodents via Aggravated Oxidative Stress and Neurochemical Changes in the Brain

The mechanisms underlying selective serotonin reuptake inhibitor (SSRI) use during pregnancy as a major autism risk factor are unclear. Here, brain neurochemical changes following fluoxetine exposure and in an autism model were compared to determine the effects on autism risk. The study was performed on neonatal male western albino rats which were divided into Groups one (control), two (propionic acid [PPA]-induced autism model), and three (prenatal SSRI-exposed newborn rats whose mothers were exposed to 5 mg/kg of fluoxetine over gestation days 10-20). SSRI (fluoxetine) induced significant neurochemical abnormalities in the rat brain by increasing lipid peroxide (MDA), Interferon-gamma (IFN-γ), and caspase-3 levels and by depleting Glutathione (GSH), Glutathione S-transferases (GST), Catalase, potassium (K+), and Creatine kinase (CK) levels, similarly to what has been discovered in the PPA model of autism when compared with control. Prenatal fluoxetine exposure plays a significant role in asset brain damage in newborns; further investigation of fluoxetine as an autism risk factor is thus warranted.

Targeting Shank3 deficiency and paresthesia in autism spectrum disorder: A brief review

Autism spectrum disorder (ASD) includes a group of multifactorial neurodevelopmental disorders characterized by impaired social communication, social interaction, and repetitive behaviors. Several studies have shown an association between cases of ASD and mutations in the genes of SH3 and multiple ankyrin repeat domain protein 3 (SHANK3). These genes encode many cell adhesion molecules, scaffold proteins, and proteins involved in synaptic transcription, protein synthesis, and degradation. They have a profound impact on all aspects of synaptic transmission and plasticity, including synapse formation and degeneration, suggesting that the pathogenesis of ASD may be partially attributable to synaptic dysfunction. In this review, we summarize the mechanism of synapses related to Shank3 in ASD. We also discuss the molecular, cellular, and functional studies of experimental models of ASD and current autism treatment methods targeting related proteins.

Confounding by Indication in Studies of Selective Serotonin Reuptake Inhibitors

Selective serotonin reuptake inhibitors (SSRIs) are used worldwide as the first-line pharmacological treatment for depression. Although SSRI use can increase the risk of suicide, fractures, and infertility, the nature of these relationships is controversial. This review reports confounding by indication and confounding by severity for SSRI side effects in previously published observational studies. The PubMed and Google Scholar databases were searched for English-language articles published from 2005 to 2022. SSRIs are often prescribed for depressive symptoms, and depression is associated with an increased risk of side effects. Therefore, confounding by indication, whereby patients are selected for a particular treatment depending on their diagnosis or severity of illness, may lead to erroneous treatment conclusions, resulting in an adverse outcome. The side effects of SSRIs that can be considered due to confounding by indication or severity include suicide, fractures, infertility, atrial fibrillation, stroke, autism spectrum disorder, and congenital malformation. When prescribing SSRIs for depression, physicians must consider confounding by indication and severity in the management of side effects. In addition, medication discontinuation should be carefully considered when side effects occur during the treatment.

Effect of Selected Antidepressants on Placental Homeostasis of Serotonin: Maternal and Fetal Perspectives

Depression is a prevalent condition affecting up to 20% of pregnant women. Hence, more than 10% are prescribed antidepressant drugs, mainly serotonin reuptake inhibitors (SSRIs) and selective serotonin and noradrenaline reuptake inhibitors (SNRIs). We hypothesize that antidepressants disturb serotonin homeostasis in the fetoplacental unit by inhibiting serotonin transporter (SERT) and organic cation transporter 3 (OCT3) in the maternal- and fetal-facing placental membranes, respectively. Paroxetine, citalopram, fluoxetine, fluvoxamine, sertraline, and venlafaxine were tested in situ (rat term placenta perfusion) and ex vivo (uptake studies in membrane vesicles isolated from healthy human term placenta). All tested antidepressants significantly inhibited SERT- and OCT3-mediated serotonin uptake in a dose-dependent manner. Calculated half-maximal inhibitory concentrations (IC₅₀) were in the range of therapeutic plasma concentrations. Using in vitro and in situ models, we further showed that the placental efflux transporters did not compromise mother-to-fetus transport of antidepressants. Collectively, we suggest that antidepressants have the potential to affect serotonin levels in the placenta or fetus when administered at therapeutic doses. Interestingly, the effect of antidepressants on serotonin homeostasis in rat placenta was sex dependent. As accurate fetal programming requires optimal serotonin levels in the fetoplacental unit throughout gestation, inhibition of SERT-/OCT3-mediated serotonin uptake may help explain the poor outcomes of antidepressant use in pregnancy.

Maternal Psychiatric Conditions, Treatment With Selective Serotonin Reuptake Inhibitors, and Neurodevelopmental Disorders

BACKGROUND

This study aims to clarify relationships of maternal psychiatric conditions and selective serotonin reuptake inhibitor (SSRI) use during preconception and pregnancy with risk of neurodevelopmental disorders in offspring.

METHODS

We used data from the Study to Explore Early Development, a multisite case-control study conducted in the United States among children born between 2003 and 2011. Final study group classifications of autism spectrum disorder (ASD) (n = 1367), developmental delays or disorders (DDs) (n = 1750), and general population controls (n = 1671) were determined by an in-person standardized developmental assessment. Maternal psychiatric conditions and SSRI use during pregnancy were ascertained from both self-report and medical records. We used logistic regression to evaluate associations of ASD and DDs (vs. population controls) with maternal psychiatric conditions and SSRI treatment in pregnancy. To reduce confounding by indication, we also examined SSRI associations in analyses restricted to mothers with psychiatric conditions during pregnancy.

RESULTS

Psychiatric conditions and SSRI use during pregnancy were significantly more common among mothers of children with either ASD or DDs than among population controls. Odds of ASD were similarly elevated among mothers with psychiatric conditions who did not use SSRIs during pregnancy (adjusted odds ratio 1.81, 95% confidence interval 1.44-2.27) as in mothers who did use SSRIs (adjusted odds ratio 2.05, 95% confidence interval 1.50-2.80). Among mothers with psychiatric conditions, SSRI use was not significantly associated with ASD in offspring (adjusted odds ratio 1.14, 95% confidence interval 0.80-1.62). Primary findings for DDs exhibited similar relationships to those observed with ASD.

CONCLUSIONS

Maternal psychiatric conditions but not use of SSRIs during pregnancy were associated with increased risk of neurodevelopmental disorders in offspring.

Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin Norepinephrine Reuptake Inhibitors (SNRIs) During Pregnancy and the Risk for Autism spectrum disorder (ASD) and Attention deficit hyperactivity disorder (ADHD) in the Offspring: A True Effect or a Bias? A Systematic Review & Meta-Analysis

BACKGROUND AND OBJECTIVE

An inconsistent association between exposure to SSRIs and SNRIs and the risk for ASD and ADHD in the Offspring was observed in observational studies. Some suggest that the reported association might be due to unmeasured confounding. We aimed to study this association and to look for sources of bias by performing a systematic review and meta-analysis.

METHODS

Medline, Embase, and the Cochrane Library were searched up to June 2019 for studies reporting on ASD and ADHD in the Offspring following exposure during pregnancy. We followed the PRISMA 2009 guidelines for data selection and extraction. Outcomes were pooled using random- effects models and odds ratios (OR), and 95% confidence intervals (CI) were calculated for each outcome using the adjusted point estimate of each study.

RESULTS

Eighteen studies were included in the meta-analysis. We found an association between SSRIs/ SNRIs prenatal use and the risk for ASD and ADHD (OR=1.42, 95% CI: 1.23-1.65, I2=58%; OR=1.26, 95% CI: 1.07-1.49, I2=48%, respectively). Similar findings were obtained in women who were exposed to SSRIs/SNRIs before pregnancy, representing statistically significant association with ASD (OR=1.39, 95% CI: 1.24-1.56, I2=33%) and ADHD (OR=1.63, 95% CI: 1.50-1.78, I2=0%) in the Offspring, although they were not exposed to those medications in utero.

CONCLUSIONS

Although we found an association between exposure to SSRIs/SNRIs during pregnancy and the risk for ASD and ADHD, an association with those disorders was also present for exposure pre-pregnancy, suggesting that the association might be due to unmeasured confounding. We are aiming to further assess the role of potential unmeasured confounding in the estimation of the association and perform a network meta-analysis.

Developmental Fluoxetine Exposure Alters Behavior and Neuropeptide Receptors in the Prairie Vole

Developmental exposure to selective serotonin reuptake inhibitor (SSRI) increases the risk of Autism Spectrum Disorder (ASD), however, the underlying neurobiology of this effect is not fully understood. Here we used the socially monogamous prairie vole as a translational model of developmental SSRI exposure. Paired female prairie voles (n = 20) were treated with 5 mg/kg subcutaneous fluoxetine (FLX) or saline (SAL) daily from birth of the second litter until the day of birth of the 4th litter. This design created three cohorts of FLX exposure: postnatal exposure in litter 2, both prenatal and postnatal exposure in litter 3, and prenatal exposure in litter 4. Post-weaning, subjects underwent behavioral testing to detect changes in sociality, repetitive behavior, pair-bond formation, and anxiety-like behavior. Quantitative receptor autoradiography was performed for oxytocin, vasopressin 1a, and serotonin 1a receptor density in a subset of brains. We observed increased anxiety-like behavior and reduced sociality in developmentally FLX exposed adults. FLX exposure decreased oxytocin receptor binding in the nucleus accumbens core and central amygdala, and vasopressin 1a receptor binding in the medial amygdala. FLX exposure did not affect serotonin 1A receptor binding in any areas examined. Changes to oxytocin and vasopressin receptors may underlie the behavioral changes observed and have translational implications for the mechanism of the increased risk of ASD subsequent to prenatal SSRI exposure.

School-age social behavior and pragmatic language ability in children with prenatal serotonin reuptake inhibitor exposure

Studies examining associations between fetal serotonin reuptake inhibitor (SRI) exposure and child autism spectrum disorder (ASD) diagnoses or delayed language remain mixed and rarely prospectively follow children or employ gold-standard assessments. We prospectively followed a cohort of mother-child dyads from pregnancy through early elementary school (N = 178), and obtained maternal and alternate-caregiver ratings of behaviors related to ASD (N = 137), as well as direct, gold-standard assessments of child ASD symptoms and pragmatic language among dyads who experienced prenatal depression and either took SRIs or were medication free during pregnancy (N = 44). Prenatal SRI exposure was related to maternal ratings of ASD-related behaviors (β = 0.24 95% confidence interval; CI [0.07, 0.48]), and, among boys, alternative caregiver ratings (males-only β = 0.28 95% CI [0.02, 0.55], females-only β = -0.21 95% CI [-0.63, 0.08]). However, results of our direct assessments suggest an association between SRI exposure and reduced pragmatic language scores (β = -0.27, 95% CI [-0.53, -0.01], but not ASD (Autism Diagnostic Observation Schedule β = 0.14 95% CI [-0.15, 0.41]; Social Responsiveness Scale β = 0.08 95% CI [-0.25, 0.40]). These discrepancies point to issues regarding how ASD is assessed, and the possibility that SRIs may be more strongly associated with language or other broader behaviors that coincide with ASD. Larger prospective studies that incorporate thorough, gold-standard assessments of ASD, language, and other ASD-related behaviors are needed.

Implementation of Advanced Methods for Reproductive Pharmacovigilance in Autism: A Meta-Analysis of the Effects of Prenatal Antidepressant Exposure

OBJECTIVE

Observational studies of prenatal antidepressant safety are hindered by methodological concerns, including susceptibility to surveillance bias. Some studies address potential bias by using alternative strategies to operationalize study comparison groups. In a meta-analysis of the association between prenatal antidepressant exposure and autism risk, the authors examined the utility of comparison group operationalization in reducing surveillance bias.

METHODS

A systematic search of multiple databases through August 2017 was conducted, selecting controlled observational studies of the association of prenatal antidepressant exposure with autism. Study quality was assessed using the Newcastle-Ottawa Scale. Random-effects meta-analysis produced summary effect measures with 95% confidence intervals stratified by comparator group composition, antidepressant class, and trimester of exposure.

RESULTS

Fourteen studies were included, with 13 reporting results using a population-based comparison group, five using a psychiatric control group, and four using a discordant-sibling control group. Eight of the 14 studies were rated poor because of inadequate control for prenatal depression and maternal ethnicity. Autism risk estimates after prenatal exposure to any antidepressant were decidedly different for population-based designs (hazard ratio=1.42, 95% CI=1.18, 1.70; odds ratio=1.58, 95% CI=1.25, 1.99) compared with psychiatric control (hazard ratio=1.14, 95% CI=0.84, 1.53; odds ratio=1.24, 95% CI=0.93, 1.66) and discordant-sibling (hazard ratio=0.97, 95% CI=0.68, 1.37; odds ratio=0.85, 95% CI=0.54, 1.35) designs. Findings for prenatal exposure to selective serotonin reuptake inhibitors were similar. Meta-regression of population-based studies demonstrated that despite statistical adjustment, ethnicity differences remained a significant source of study heterogeneity.

CONCLUSIONS

In this meta-analysis, neither psychiatric control nor discordant-sibling designs supported an association between prenatal antidepressant exposure and autism. Discordant-sibling designs effectively addressed surveillance bias in pharmacovigilance reports derived from national registries and other large databases.

Maternal Prenatal Exposures in Pregnancy and Autism Spectrum Disorder: An Insight into the Epigenetics of Drugs and Diet as Key Environmental Influences

Autism spectrum disorder (ASD) is a rapidly growing global pandemic that affects an estimated 1 in 59-68 children. It is a complex disease with both genetic and environmental etiologies. Due to the rapid increase in the incidence of ASD, environmental causes for ASD are gaining attention. Efforts to probe several environmental exposures that could contribute to causing ASD are underway. In this regard, this chapter is directed towards understanding prenatal exposure to key environmental factors i.e., drugs and dietary nutrients that may act via the same molecular pathway - epigenetics as a potential etiological factor for ASD. Epigenetic regulation is a molecular mechanism known to be a significant contributor to neurodevelopmental disorders. It also offers a means to explain how environmental exposures can impact genetics. We discuss the impact of maternal exposures to certain drugs, and dietary intake, on the developing fetus during pregnancy. Maternal Exposure to some drugs during gestation are associated with a higher risk of ASD, while exposure to other dietary compounds may offer promise to rescue epigenetic regulatory insults related to ASD. However, more work in this important area is still required, nevertheless preliminary research already has important implications in the understanding, prevention and treatment of ASD.

Advances in Epidemiological Methods and Utilisation of Large Databases: A Methodological Review of Observational Studies on Central Nervous System Drug Use in Pregnancy and Central Nervous System Outcomes in Children

INTRODUCTION

Studies have used various epidemiological approaches to study associations between central nervous system (CNS) drug use in pregnancy and CNS outcomes in children. Studies have generally focused on clinical adverse effects, whereas variations in methodologies have not received sufficient attention.

OBJECTIVE

Our objective was to review the methodological characteristics of existing studies to identify any limitations and recommend further research.

METHODS

A systematic literature search was conducted on observational studies listed in PubMed from 1 January 1946 to 21 September 2017. Following independent screening and data extraction, we conducted a review addressing the trends of relevant studies, differences between various data sources, and methods used to address bias and confounders; we also conducted statistical analyses.

RESULTS

In total, 111 observational studies, 25 case-control studies, and 86 cohort studies were included in the review. Publications dating from 1978 to 2006 mainly focused on antiepileptic drugs, but research on antidepressants increased from 2007 onwards. Only one study focused on antipsychotic use during pregnancy. A total of 46 studies obtained data from an administrative database/registry, 20 from ad hoc disease registries, and 41 from ad hoc clinical samples. Most studies (58%) adjusted the confounding factors using general adjustment, whereas only a few studies used advanced methods such as sibling-matched models and propensity score methods; 42 articles used univariate analyses and 69 conducted multivariable regression analyses.

CONCLUSION

Multiple factors, including different study designs and data sources, have led to inconsistent findings in associations between CNS drug use in pregnancy and CNS outcomes in children. Researchers should allow for study designs with clearly defined exposure periods, at the very least in trimesters, and use advanced confounding adjustment methodology to increase the accuracy of the findings.

Pregnant women, prescription, and fetal risk

Since the historical scandal of thalidomide in the 1960s, practitioners and future mothers are fearful of drugs during pregnancy. In-uterine exposure to drugs can induce major malformation of the fetus or even intrauterine fetal death. Prescribing drugs to a pregnant woman requires particular attention, and it is necessary to consider both the maternal needs and the proven and potential fetal risks. In this chapter, we review the mechanisms for medication transfer from mother to fetus, fetal risk according to pregnancy timeline, and the main dangerous drugs during pregnancy. We also focus on three prescription debates, which are relevant for neurodevelopmental disorder, because they each point to a paradigmatic situation-diethylstilbestrol, which shows transgenerational adversary effects; valproate, which impacts neurodevelopment as a whole; and antidepressants for which the adverse impact on neurodevelopment is still controversial given the impact of depression itself. Finally, we consider the implications for practice and toxicologic research to promote risk prevention.

The Association Between Prenatal Exposure to Antidepressants and Autism: Some Research and Public Health Aspects

Use of antidepressants (ADs) in general, and in pregnant notwithstanding, has been increasing globally in recent decades. Associations with a wide range of adverse perinatal and childhood outcomes following prenatal ADs exposure have been observed in registry-based studies, with Autism Spectrum Disorders (ASD) frequently reported. Studies using animal models, sibling analyses, and negative control approaches, have linked dysfunctional serotonin metabolism with ASD, but did not convincingly tease apart the role of maternal mental health from that of ADs. As work to decipher the nature of the AD-ASD association continues, this review raises some public health concerns pertinent to a hypothetical conclusion that this association is causal, including the need to identify specific gestation periods with higher risk, the importance of precise assessment of the ASD potential prevention that might be attributed to AD discontinuation, and the estimation of risks associated with prenatal exposure to untreated depression.

Antenatal exposure to antidepressant drugs and the risk of neurodevelopmental and psychiatric disorders: a systematic review

Abstract: This study investigated whether antenatal exposure to antidepressants (ADs) increases the risks of autism spectrum disorders (ASD), attention deficit/hyperactivity disorders (ADHD), schizophrenia and other mental illnesses, and cognitive and developmental deficits in infants or preschool children. PubMed, EMBASE, BIREME/BVS databases were searched to identify studies examining associations of ADs in pregnancy with neurodevelopmental and psychiatric disorders. Twenty studies addressed ASD and/or ADHD risks while 30 focused on developmental and cognitive deficits in infants or preschool children. Most studies detected no association of antenatal AD with ASD after adjustment of risk ratios for maternal depression or psychiatric disorders. Some studies showed that maternal depression, regardless of whether it is treated or untreated, increased ASD risks. Seven out of 8 studies found no increase in ADHD risk associated with antenatal exposure to selective serotonin reuptake inhibitors, the most commonly used AD. No consistent evidence was found linking AD in pregnancy to neurocognitive developmental deficits in infants or preschool children. A residual confounding by indication (depression severity) remained in almost all studies. This systematic review found no consistent evidence suggesting that ADs in pregnancy increase risks of ASD, ADHD, and neurocognitive development deficits. Some studies, however, found evidence that maternal depression increases ASD risks.

Autism spectrum disorder: Trends in research exploring etiopathogenesis

Autism spectrum disorder is a neurodevelopmental condition in which affected individuals have difficulties while interacting and communicating socially, and repetitive behaviors. It has a multifactorial etiology. Various risk factors, including genetic and environmental influences, have been explored while trying to understand its causation. As older evidence was suggestive of a high heritability, a majority of research focused on finding the underlying genetic causes of autism. Due to these efforts, there have been advances in the knowledge of some of the genetic factors associated with autism. But a recent trend also shows an increasing interest in exploration of various potential environmental triggers. These efforts have brought us closer to understanding the elusive disorder more so than ever before. The current review discusses the recent trends in research exploring the etiopathogenesis of autism spectrum disorder.

Use and validity of child neurodevelopment outcome measures in studies on prenatal exposure to psychotropic and analgesic medications - A systematic review

In recent years there has been increased attention to child neurodevelopment in studies on medication safety in pregnancy. Neurodevelopment is a multifactorial outcome that can be assessed by various assessors, using different measures. This has given rise to a debate on the validity of various measures of neurodevelopment. The aim of this review was twofold. Firstly we aimed to give an overview of studies on child neurodevelopment after prenatal exposure to central nervous system acting medications using psychotropics and analgesics as examples, giving special focus on the use and validity of outcome measures. Secondly, we aimed to give guidance on how to conduct and interpret medication safety studies with neurodevelopment outcomes. We conducted a systematic review in the MEDLINE, Embase, PsycINFO, Web of Science, Scopus, and Cochrane databases from inception to April 2019, including controlled studies on prenatal exposure to psychotropics or analgesics and child neurodevelopment, measured with standardised psychometric instruments or by diagnosis of neurodevelopmental disorder. The review management tool Covidence was used for data-extraction. Outcomes were grouped as motor skills, cognition, behaviour, emotionality, or "other". We identified 110 eligible papers (psychotropics, 82 papers, analgesics, 29 papers). A variety of neurodevelopmental outcome measures were used, including 27 different psychometric instruments administered by health care professionals, 15 different instruments completed by parents, and 13 different diagnostic categories. In 23 papers, no comments were made on the validity of the outcome measure. In conclusion, establishing neurodevelopmental safety includes assessing a wide variety of outcomes important for the child's daily functioning including motor skills, cognition, behaviour, and emotionality, with valid and reliable measures from infancy through to adolescence. Consensus is needed in the scientific community on how neurodevelopment should be assessed in medication safety in pregnancy studies. Review registration number: CRD42018086101 in the PROSPERO database.

In utero exposure to selective serotonin reuptake inhibitors and development of mental disorders: a systematic review and meta-analysis

OBJECTIVE

Several studies have investigated whether in utero exposure to selective serotonin reuptake inhibitors (SSRIs) is associated with increased risk of developing mental or behavioural disorders. The aim of this study was to perform a systematic review and meta-analysis based on this literature.

METHODS

A systematic search of eligible literature in PubMed, EMBASE, and PsycINFO and subsequent meta-analysis was conducted in adherence with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline.

RESULTS

A total of 20 studies were included in the review, and results from 18 of these were meta-analyzed. We found a statistically significant positive association between in utero exposure to SSRIs and mental or behavioural disorders such as autism spectrum disorder (hazard ratio (HR) = 1.27; 95% confidence interval (CI) = 1.10-1.47), attention-deficit/hyperactivity disorder (HR = 1.33; 95% CI = 1.06-1.66) and mental retardation (HR = 1.41; 95% CI = 1.03-1.91). Confounding by indication was identified in five of seven studies investigating this aspect.

CONCLUSION

Exposure to SSRIs in utero is associated with increased risk of developing mental or behavioural disorders. However, these associations do not necessarily reflect a causal relationship since the results included in this meta-analysis are likely affected by residual confounding by indication, which is likely to account for some (or all) of the positive association.

Annual Research Review: Maternal antidepressant use during pregnancy and offspring neurodevelopmental problems - a critical review and recommendations for future research

Children of women treated with antidepressants during pregnancy are more likely to develop neurodevelopmental problems than are unexposed children. Associations between prenatal antidepressant exposure and neurodevelopmental problems could reflect a causal effect or could be partially or fully explained by other factors that differ between exposed and unexposed offspring, including having mothers with conditions requiring antidepressant treatment (e.g. depression), environmental risk factors, and/or genetic risk factors shared across disorders. This translational review aims to provide a brief overview of findings from rodent experiments and critically evaluate observational studies in humans to assess the extent to which associations between prenatal antidepressant exposure and neurodevelopmental problems are due to causal mechanisms versus other influences. We focus our review on two important neurodevelopmental outcomes - autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). In general, rodent studies have reported adverse effects of perinatal antidepressant exposure on neurodevelopment. Between-species differences raise questions about the generalizability of these findings to humans. Indeed, converging evidence from studies using multiple designs and approaches suggest that observed associations between prenatal antidepressant exposure and neurodevelopmental problems in humans are largely due to confounding factors. We also provide specific recommendations for future research. Animal research should explicitly evaluate the impact of timing of exposure and dosage of medications, as well as better map outcome measures in rodents to human neurodevelopmental problems. Observational studies should investigate specific confounding factors, specific antidepressant drugs and classes, the potential impact of timing of exposure, and a wider range of other potential offspring outcomes. The findings summarized in this review may help women and their doctors make informed decisions about antidepressant use during pregnancy by providing reassurance that use of these medications during pregnancy is unlikely to substantially increase the risk of ASD and ADHD.

Risk of autistic spectrum disorder in offspring with parental mood disorders: A systematic review and meta-analysis

BACKGROUND

The association between mood disorders in parents and autism spectrum disorder (ASD) risk in offspring has been investigated in several studies, but the evidence is inconclusive. This systematic review and meta-analysis will explore whether an association exists between parental mood disorders and ASD risk in offspring.

METHODS

A literature search was performed using the electronic databases PubMed, EMBASE, PsycINFO, and Scopus. We also reviewed reference lists from retrieved articles. Meta-analysis was conducted, and combined effect values and their 95% confidence intervals were calculated. Study-specific risk ratios (RRs) were pooled using a random effect model. The risk of publication bias was assessed by funnel plot and Egger's regression asymmetry test.

RESULTS

Nine observational studies (two cohort and seven case-control studies) were included for analysis. Our meta-analysis found a greater risk of ASD in children exposed to parental affective, depressive, and bipolar disorders [(RRs 1.65 (95%CI 1.45-1.88); 1.37 (95%CI 1.04-1.81) and 1.87; 95%CI 1.69-2.07) respectively]. We also found increased ASD risk in children of mothers who experienced affective and depressive disorders [(RRs 1.67 (95%CI 1.34-2.09) and 1.62 (95%CI 1.32-1.99) respectively]. We found no increased risk of ASD in children exposed to paternal affective and depressive disorders. Subgroup and sensitivity analysis confirmed the robustness of our main analysis.

CONCLUSION

The evidence from the present study suggests parental affective, depressive and bipolar, as well as maternal affective and depressive disorders increased the risk of ASD in offspring. Exposure to affective and depressive disorders in fathers only was not linked with ASD risk in children.

Rational use of mesenchymal stem cells in the treatment of autism spectrum disorders

Autism and autism spectrum disorders (ASD) refer to a range of conditions characterized by impaired social and communication skills and repetitive behaviors caused by different combinations of genetic and environmental influences. Although the pathophysiology underlying ASD is still unclear, recent evidence suggests that immune dysregulation and neuroinflammation play a role in the etiology of ASD. In particular, there is direct evidence supporting a role for maternal immune activation during prenatal life in neurodevelopmental conditions. Currently, the available options of behavioral therapies and pharmacological and supportive nutritional treatments in ASD are only symptomatic. Given the disturbing rise in the incidence of ASD, and the fact that there is no effective pharmacological therapy for ASD, there is an urgent need for new therapeutic options. Mesenchymal stem cells (MSCs) possess immunomodulatory properties that make them relevant to several diseases associated with inflammation and tissue damage. The paracrine regenerative mechanisms of MSCs are also suggested to be therapeutically beneficial for ASD. Thus the underlying pathology in ASD, including immune system dysregulation and inflammation, represent potential targets for MSC therapy. This review will focus on immune dysfunction in the pathogenesis of ASD and will further discuss the therapeutic potential for MSCs in mediating ASD-related immunological disorders.

Risk and Protective Environmental Factors Associated with Autism Spectrum Disorder: Evidence-Based Principles and Recommendations

Autism Spectrum Disorder (ASD) is a complex condition with early childhood onset, characterized by a set of common behavioral features. The etiology of ASD is not yet fully understood; however, it reflects the interaction between genetics and environment. While genetics is now a well-established risk factor, several data support a contribution of the environment as well. This paper summarizes the conclusions of a consensus conference focused on the potential pathogenetic role of environmental factors and on their interactions with genetics. Several environmental factors have been discussed in terms of ASD risk, namely advanced parental age, assisted reproductive technologies, nutritional factors, maternal infections and diseases, environmental chemicals and toxicants, and medications, as well as some other conditions. The analysis focused on their specific impact on three biologically relevant time windows for brain development: the periconception, prenatal, and early postnatal periods. Possible protective factors that might prevent or modify an ASD trajectory have been explored as well. Recommendations for clinicians to reduce ASD risk or its severity have been proposed. Developments in molecular biology and big data approaches, which are able to assess a large number of coexisting factors, are offering new opportunities to disentangle the gene⁻environment interplay that can lead to the development of ASD.

Extreme enhancement or depletion of serotonin transporter function and serotonin availability in autism spectrum disorder

A variety of human and animal studies support the hypothesis that serotonin (5-hydroxytryptamine or 5-HT) system dysfunction is a contributing factor to the development of autism in some patients. However, many questions remain about how developmental manipulation of various components that influence 5-HT signaling (5-HT synthesis, transport, metabolism) persistently impair social behaviors. This review will summarize key aspects of central 5-HT function important for normal brain development, and review evidence implicating perinatal disruptions in 5-HT signaling in the pathophysiology of autism spectrum disorder. We discuss the importance, and relative dearth, of studies that explore the possible correlation to autism in the interactions between important intrinsic and extrinsic factors that may disrupt 5-HT homeostasis during development. In particular, we focus on exposure to 5-HT transport altering mechanisms such as selective serotonin-reuptake inhibitors or genetic polymorphisms in primary or auxiliary transporters of 5-HT, and how they relate to neurological stores of serotonin and its precursors. A deeper understanding of the many mechanisms by which 5-HT signaling can be disrupted, alone and in concert, may contribute to an improved understanding of the etiologies and heterogeneous nature of this disorder. We postulate that extreme bidirectional perturbations of these factors during development likely compound or synergize to facilitate enduring neurochemical changes resulting in insufficient or excessive 5-HT signaling, that could underlie the persistent behavioral characteristics of autism spectrum disorder.

Perinatal exposure to fluoxetine increases anxiety- and depressive-like behaviours and alters glutamatergic markers in the prefrontal cortex and hippocampus of male adolescent rats: A comparison between Sprague-Dawley rats and the Wistar-Kyoto rat model of depression

BACKGROUND

With approximately 10% of pregnant women prescribed antidepressant drugs for the treatment of depressive disorders, there is growing concern regarding the potential long-term effects of this exposure on offspring. Research is needed in clinically relevant models to determine the effects on offspring behaviour and associated neurobiological systems.

AIM

The aim of this study was to determine the effects of maternal fluoxetine treatment on anxiety-like and depressive-like behaviours in adolescent offspring as well as associated glutamatergic markers, using a clinically relevant rodent model of depression.

METHODS

Wistar-Kyoto (model of innate depression) and Sprague-Dawley rats were treated with fluoxetine (10 mg/kg) from gestational day 0 to postnatal day 14. Male offspring underwent behavioural testing (open field, elevated plus maze, forced swim test) at adolescence followed by quantitative immuno-detection of glutamatergic markers in the prefrontal cortex and ventral hippocampus.

RESULTS

Perinatal fluoxetine exposure exacerbated the anxiety-like and depressive-like phenotype in Wistar-Kyoto offspring and induced an anxiety-like and depressive-like phenotype in Sprague-Dawley offspring. Wistar-Kyoto offspring showed reductions in NMDA receptor NR1, NR2A and NR2B subunits, as well as post-synaptic density 95 (PSD-95) and metabotropic glutamate receptor subtype 1 (mGluR1) in the prefrontal cortex; perinatal fluoxetine exposure further reduced NR1, NR2A, PSD-95 and mGluR1 expression in Wistar-Kyoto as well as Sprague-Dawley offspring. In the ventral hippocampus perinatal fluoxetine exposure reduced PSD-95 and increased metabotropic glutamate receptor subtype 5 (mGluR5) and Homer1b/c in both Sprague-Dawley and Wistar-Kyoto strains.

CONCLUSION

These findings suggest that maternal fluoxetine treatment exacerbates effects of underlying maternal depression on offspring behaviour, which may be mediated through alterations in the glutamatergic system. Further research investigating how to minimise these effects, whilst ensuring optimal treatment for mothers, is essential to move the field forward.

Association between antidepressant use during pregnancy and autism spectrum disorder in children: a retrospective cohort study based on Japanese claims data

Background

Studies using data from Western countries have raised concerns that treating pregnant women with antidepressants may increase the risk of autism spectrum disorders (ASDs) in their offspring. However, to date, the studies are inconclusive. We therefore examined the association between antidepressant use and ASD using claims data collected in Japan.

Methods

This retrospective cohort study was based on claims data from mothers and their children from January 2005 to July 2014, obtained from the Japan Medical Data Center. The information from mothers and children was linked using the family identification code. Information on antidepressant prescriptions during pregnancy was extracted from the database. To collect information on ASD, children for whom data were available 24 months or more after birth were followed up from birth through July 2014 or up until their withdrawal from the database. To ensure appropriate diagnosis of ASD, mother-child pairs where the children's data did not cover the 24 months after birth or pairs where children had a diagnosis of ASD within only 23 months after birth were excluded from the study cohort. We used logistic regression analyses to evaluate the association between antidepressant use during pregnancy and the children's ASD diagnosis. All statistical analyses were performed using IBM SPSS (Statistical Package for the Social Sciences) Statistics ver. 21.0.

Results

Of the 53,864 eligible mother-child pairs, 26,925 met the study criteria. Crude analysis showed that the ASD prevalence in children was significantly higher with any antidepressant use than with non-use (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.08, 4.95). However, when the analysis was adjusted for the confounding effect of maternal depression during pregnancy, statistical significance was lost (OR, 0.76; CI, 0.27, 2.18).

Conclusions

After adjustment for confounders, we found no significant association between antidepressant use during pregnancy and ASD in children in Japan. This result provides additional evidence to support the idea that antidepressant use during pregnancy itself is not associated with an increase in ASD in children. In addition, this represents the first evidence based on Asian data.

Hypoxia and connectivity in the developing vertebrate nervous system

The developing nervous system depends upon precise regulation of oxygen levels. Hypoxia, the condition of low oxygen concentration, can interrupt developmental sequences and cause a range of molecular, cellular and neuronal changes and injuries. The roles and effects of hypoxia on the central nervous system (CNS) are poorly characterized, even though hypoxia is simultaneously a normal component of development, a potentially abnormal environmental stressor in some settings, and a clinically important complication, for example of prematurity. Work over the past decade has revealed that hypoxia causes specific disruptions in the development of CNS connectivity, altering axon pathfinding and synapse development. The goals of this article are to review hypoxia's effects on the development of CNS connectivity, including its genetic and molecular mediators, and the changes it causes in CNS circuitry and function due to regulated as well as unintended mechanisms. The transcription factor HIF1α is the central mediator of the CNS response to hypoxia (as it is elsewhere in the body), but hypoxia also causes a dysregulation of gene expression. Animals appear to have evolved genetic and molecular responses to hypoxia that result in functional behavioral alterations to adapt to the changes in oxygen concentration during CNS development. Understanding the molecular pathways underlying both the normal and abnormal effects of hypoxia on CNS connectivity may reveal novel insights into common neurodevelopmental disorders. In addition, this Review explores the current gaps in knowledge, and suggests important areas for future studies.

Summary: The nervous system's exposure to hypoxia has developmental and clinical relevance. In this Review, the authors discuss the effects of hypoxia on the development of the CNS, and its long-term behavioral and neurodevelopmental consequences.

Maternal Serotonin Levels Are Associated With Cognitive Ability and Core Symptoms in Autism Spectrum Disorder

OBJECTIVE

The serotonin (5-hydroxytryptamine [HT]) system has long been implicated in autism spectrum disorder (ASD). Whole-blood 5-HT level (WB5-HT) is a stable, heritable biomarker that is elevated in more than 25% of children with ASD. Recent findings indicate that the maternal 5-HT system may influence embryonic neurodevelopment, but maternal WB5-HT has not been examined in relation to ASD phenotypes.

METHOD

WB5-HT levels were obtained from 181 individuals (3-27 years of age) diagnosed with ASD, 99 of their fathers, and 119 of their mothers. Standardized assessments were used to evaluate cognitive, behavioral, and language phenotypes.

RESULTS

Exploratory regression analyses found relationships between maternal WB5-HT and nonverbal IQ (NVIQ), Autism Diagnostic Interview-Revised (ADI-R) Nonverbal Communication Algorithm scores, and overall adaptive function on the Vineland Adaptive Behavior Scales-II. Latent class analysis identified a three-class structure in the assessment data, describing children with low, intermediate, and high severity across measures of behavior, cognition, and adaptive function. Mean maternal WB5-HT differed across classes, with the lowest maternal WB5-HT levels seen in the highest-severity group (Welch F_2,46.048 = 17.394, p < .001). Paternal and proband WB5-HT did not differ between classes.

CONCLUSION

Maternal WB5-HT is associated with neurodevelopmental outcomes in offspring with ASD. Prospective, longitudinal studies will be needed to better understand the relationship between the function of the maternal serotonin system during pregnancy and brain development. Further studies in animal models may be able to reveal the mechanisms underlying these findings.

Maternal depression and antidepressant use during pregnancy and the risk of autism spectrum disorder in offspring

Background

Results of some studies suggest that prenatal antidepressant exposure increases the risk of autism spectrum disorder (ASD) in offspring, while other studies suggest that depression independently increases the risk of having a child with ASD. Thus, confounding by indication is a concern.

Objective

The aim of this study was to estimate the risk of ASD in offspring of women who were exposed to antidepressants and/or had depression during pregnancy compared to unexposed women.

Materials and methods

We conducted a cohort study with nested sibling case–control analysis. Using the UK Clinical Practice Research Datalink (CPRD), we identified mother– baby pairs where the mother had ≥12 months of history before the delivery date and the child had ≥3 years of follow-up. Exposures during pregnancy were classified as 1) depression treated with antidepressants, 2) untreated depression, 3) other indications for antidepressant use, and 4) 4:1 match of unexposed women with no history of depression or antidepressant use. We calculated the prevalence of ASD and relative risk (RR) with 95% CI. In the sibling analysis, we compared exposure among ASD cases to that of non-ASD siblings born to the same mother. We calculated ORs and 95% CIs for women with treated and untreated depression, compared to unexposed.

Results

We identified 2,154 offspring with ASD among 194,494 mother–baby pairs. Compared to unexposed, the RR of ASD was 1.72 (95% CI 1.54–1.93) for treated depression and 1.50 (95% CI 1.28–1.75) for untreated depression, while the RR was not elevated in women who received antidepressants for other indications (RR =0.73, 95% CI 0.41–1.29). Additional analyses to assess the effects of severity of depression suggest that the risk of ASD in offspring increases with increasing severity, not with the antidepressant treatment. The results of the sibling analysis were similar to the main analysis.

Conclusion

Women with depression during pregnancy have an increased risk of having a child with ASD, regardless of antidepressant use.

Prenatal, perinatal, and neonatal risk factors of autism spectrum disorder

BACKGROUND

We explored the association of 29 previously reported neonatal, perinatal, and prenatal conditions, and exposures with later diagnosis of autism spectrum disorder (ASD) in a large sample of children followed over multiple years.

METHODS

A retrospective case-cohort study was formed using the Military Health System database. Cases were identified by International Classification of Diseases, Ninth Revision codes for ASD between 2000 and 2013, and were matched 3:1 with controls on sex, date of birth, and enrollment time frame. Exposures included 29 conditions previously associated with ASD; 17 prenatal conditions and their pharmaceutical treatment, 5 perinatal conditions, and 6 neonatal conditions.

RESULTS

A total of 8,760 children diagnosed with ASD between the ages of 2 and 18 years were matched with 26,280 controls. ASD is associated with maternal mental illness, epilepsy, obesity, hypertension, diabetes, polycystic ovary syndrome, infection, asthma, assisted fertility, hyperemesis, younger maternal age, labor complications, low birth weight, infant infection, epilepsy, birth asphyxia, and newborn complications. The greatest increased risk was associated with infant epilepsy (odds ratio (OR) 7.57 (5.68-10.07)), maternal mental health (OR 1.80 (1.65-1.96)), and epilepsy (OR 1.60 (1.02-2.50)) medications.

CONCLUSION

ASD is associated with a range of prenatal, perinatal, and neonatal factors, with the highest magnitude associations with maternal medication use and neonatal seizure.

Memantine rescues prenatal citalopram exposure-induced striatal and social abnormalities in mice

Prenatal exposure to citalopram (CTM), an antidepressant drug, has been associated with altered behavior, including autism-like symptoms in both human and rodent offspring. However, the neurological basis underlying these abnormal behaviors is not well understood. Here, we examined behavioral, morphological, and biochemical alterations in the male and female offspring of C57BL/6 mouse mothers that had been exposed to CTM during the last trimester of gestation. We observed abnormal behavior such as anxiety, altered locomotion and disordered social interactions in 2-5 months old offspring with prenatal CTM exposure. Using Golgi-Cox staining, we found that CTM caused significantly reduced dendritic length and number of dendritic branches in striatal neurons, as well as altered subunit levels of N-methyl-d-aspartate receptors (NMDARs) and calcium/calmodulin-dependent protein kinase II (CaMKII). Memantine, a selective NMDAR antagonist, improved prenatal CTM-induced abnormal protein levels and social interaction deficits. These results highlight potential mechanisms underlying the abnormal behavior observed in children who are prenatally exposed to CTM.

Interactive Effects of Prenatal Antidepressant Exposure and Likely Gene Disrupting Mutations on the Severity of Autism Spectrum Disorder

To examine the interactive effects of two proposed risk factors which may contribute to symptom severity of Autism Spectrum Disorder (ASD): prenatal antidepressant exposure and likely gene-disrupting (LGD) mutations. Participants included 2748 individuals with ASD from the Simons Simplex Collection. We examined the effects of prenatal antidepressant exposure, maternal depression, presence of an LGD mutation and their interaction on ASD severity. We found a significant interactive effect between antidepressant exposure and the presence of an LGD mutation on ASD severity in the ADOS and ADI-R verbal communication domains. We consider a "two-hit" model in which one variable lays the foundation for an initial risk which is compounded by a second variable.

Autism Spectrum Disorder: Classification, diagnosis and therapy

Autism Spectrum Disorder (ASD) refers to a group of neurodevelopmental disorders including autism, Asperger's syndrome (AS) and pervasive developmental disorder-not otherwise specified (PDD-NOS). The new diagnostic criteria of ASD focuses on two core domains: social communication impairment and restricted interests/repetitive behaviors. The prevalence of ASD has been steadily increasing over the past two decades, with current estimates reaching up to 1 in 36 children. Hereditary factors, parental history of psychiatric disorders, pre-term births, and fetal exposure to psychotropic drugs or insecticides have all been linked to higher risk of ASD. Several scales such as the Childhood Autism Rating Scale (CARS), The Autism Spectrum Disorder-Observation for Children (ASD-OC), The Developmental, Dimensional, and Diagnostic Interview (3di), are available to aid in better assessing the behaviors and symptoms associated with ASD. Nearly 75% of ASD patients suffer from comorbid psychiatric illnesses or conditions, which may include attention-deficit hyperactivity disorder (ADHD), anxiety, bipolar disorder, depression, Tourette syndrome, and others. Both pharmacological and non-pharmacological interventions are available for ASD. Pharmacological treatments include psychostimulants, atypical antipsychotics, antidepressants, and alpha-2 adrenergic receptor agonists. These medications provide partial symptomatic relief of core symptoms of ASD or manage the symptoms of comorbid conditions. Non-pharmacological interventions, which show promising evidence in improving social interaction and verbal communication of ASD patients, include music therapy, cognitive behavioral therapy and social behavioral therapy. Hormonal therapies with oxytocyin or vasopressin receptor antagonists have also shown some promise in improving core ASD symptoms. The use of vitamins, herbal remedies and nutritional supplements in conjunction with pharmacological and behavioral treatment appear to have some effect in symptomatic improvement in ASD, though additional studies are needed to confirm these benefits. Developing novel disease-modifying therapies may prove to be the ultimate intervention for sustained improvement of symptoms in ASD.

Association between maternal antidepressant use during pregnancy and autism spectrum disorder: an updated meta-analysis

Studies have investigated the risk of autism spectrum disorder (ASD) in children exposed in utero to antidepressant, with inconsistent results. Given the substantial public health implications on this topic, here, we presented an updated meta-analysis of the association between maternal antidepressant use during pregnancy and ASD. Cochrane Library, EMBASE, PsycINFO, and PubMed databases were systematically searched. A random effects model was used to pool the adjusted relative risk (RR) for cohort studies and the adjusted odds ratio (OR) for case-control studies as well as their corresponding 95% confidence intervals (CIs). Meta-analysis restricted to sibling studies was also conducted. Publication bias was systematically assessed. Fourteen studies were identified (eight cohort studies and six case-control studies). Pooled adjusted RR for cohort studies (n = 2,839,980) was 1.13 (0.93–1.39) showed a non-significant association; while two studies were potentially missing from the test of publication bias, filled estimates also showed a non-significant association (filled RR 0.97, 95% CI 0.79–1.19). Pooled OR was 1.51 (1.15–1.99) for case-control studies (n = 117,737) showed a significant association; two studies were potentially missing; however, the filled estimates suggested a non-significant association (filled OR 1.26, 95% CI 0.98–1.62). Analyses restricted to sibling studies also showed a non-significant association (RR 0.99, 95% CI 0.81–1.22). In summary, we did not evidence a significant association between maternal antidepressant use during pregnancy and ASD.

Antidepressant use during pregnancy and risk of autism spectrum disorder and attention deficit hyperactivity disorder: systematic review of observational studies and methodological considerations

BACKGROUND

Antidepressant exposure during pregnancy has been associated with an increased risk of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) in several observational studies. We performed a systematic review of these studies to highlight the effect that important methodological limitations have on such analyses and to consider approaches to the conduct, reporting and interpretation of future studies.

METHODS

A review of MEDLINE and EMBASE identified case-control, cohort and sibling studies assessing the risk of ASD and ADHD with antidepressant use during pregnancy. Approaches to confounding adjustment were described. Crude and adjusted effect estimates for comparisons between antidepressant exposure during pregnancy vs. all unexposed women were first meta-analysed using a generic inverse variance method of analysis, followed by effect estimates for alternative pre-selected comparison groups.

RESULTS

A total of 15 studies measuring ASD as an outcome (involving 3,585,686 children and 40,585 cases) and seven studies measuring ADHD as an outcome (involving 2,765,723 patients and 52,313 cases) were identified. Variation in confounding adjustment existed between studies. Updated effect estimates for the association between maternal antidepressant exposure during pregnancy vs. all unexposed women remained statistically significant for ASD (adjusted random-effects risk ratio [RaRR] 1.53, 95% confidence interval [CI] 1.31-1.78). Similar significant associations were observed using pre-pregnancy maternal antidepressant exposure (RaRR 1.48, 95% CI 1.29-1.71) and paternal antidepressant exposure during pregnancy (1.29, 95% CI 1.08-1.53), but analyses restricted to using women with a history of affective disorder (1.18, 95% CI 0.91-1.52) and sibling studies (0.96, 95% CI 0.65-1.42) were not statistically significant. Corresponding associations for risk of ADHD with exposure were: RaRR 1.38, 95% CI 1.13-1.69 (during pregnancy), RaRR 1.38, 95% CI 1.14-1.69 (during pre-pregnancy), RaRR 1.71, 95% CI 1.31-2.23 (paternal exposure), RaRR 0.98, 95% CI 0.77-1.24 (women with a history of affective disorder) and RaRR 0.88, 95% CI 0.70-1.11 (sibling studies).

CONCLUSIONS

Existing observational studies measuring the risk of ASD and ADHD with antidepressant exposure are heterogeneous in their design. Classical comparisons between exposed and unexposed women during pregnancy are at high risk of residual confounding. Alternative comparisons and sibling designs may aid the interpretation of causality and their utility requires further evaluation, including understanding potential limitations of undertaking meta-analyses with such data.

Risk of autism spectrum disorder in offspring following paternal use of selective serotonin reuptake inhibitors before conception: a population-based cohort study

OBJECTIVE

The present study aimed to examine the association between paternal selective serotonin reuptake inhibitor (SSRI) use before conception and the risk of autism spectrum disorder (ASD) in offspring.

DESIGN

A population-based cohort study.

METHODS

We conducted a cohort study of 669 922 children born from 1998 to 2008, with follow-up throughout 2013. Based on Danish national registers, we linked information on paternal use of SSRIs, ASD diagnosed in children and a range of potential confounders. The children whose fathers used SSRIs during the last 3 months prior to conception were identified as the exposed. Cox regression model was used to estimate the HR for ASD in children.

RESULTS

Compared with unexposed children, the exposed had a 1.62-fold higher risk of ASD (95% CI 1.33 to 1.96) and the risk attenuated after adjusting for potential confounders, especially fathers' psychiatric conditions (HR=1.43, 95% CI 1.18 to 1.74). When extending the exposure window to 1 year before conception, the increased risk persisted in children of fathers using SSRIs only from the last year until the last 3 months prior to conception (HR=1.54, 95% CI 1.21 to 1.94) but not in children of fathers using SSRIs only during the last 3 months prior to conception (HR=1.17, 95% CI 0.75 to 1.82). We also performed stratified analyses according to paternal history of affective disorders and observed no increased ASD risk among children whose father had affective disorders. Besides, the sibling analysis showed that the ASD risk did not increase among exposed children compared with their unexposed siblings.

CONCLUSIONS

The mildly increased risk of ASD in the offspring associated with paternal SSRI use before conception may be attributable to paternal underlying psychiatric indications related to SSRI use or other unmeasured confounding factors.

Autism risk following antidepressant medication during pregnancy

BACKGROUND

Previous studies have examined if maternal antidepressant medication during pregnancy increase the risk of autism spectrum disorder (ASD) in the offspring, but the results have been conflicting.

METHODS

In a population-based cohort of 179 007 children born in 2006 and 2007 and followed through 2014 when aged 7 and 8, we estimated relative risks (RRs) of ASD and 95% confidence intervals (CIs) from Cox regression in children exposed to any antidepressant medication during pregnancy, and nine specific antidepressant drugs. Analyses were adjusted for potential confounders and were conducted in the full population sample, and in a clinically relevant sub-sample of mothers with at least one diagnosis of depression or anxiety during life.

RESULTS

The adjusted RR of ASD in children of mothers who used antidepressant medication during pregnancy was estimated at 1.23 (95% CI 0.96-1.57), and at 1.07 (95% CI 0.80-1.43) in women with a history of depression or anxiety. Analyses of specific antidepressants initially revealed increased RRs of offspring ASD confined to citalopram and escitalopram (RR: 1.47; 95% CI 0.92-2.35) and clomipramine (RR: 2.86; 95% CI 1.04-7.82).

CONCLUSION

Medication with antidepressants during pregnancy does not appear to be causally associated with an increased risk of ASD in the offspring. Instead, the results suggest that the association is explained by factors related to the underlying susceptibility to psychiatric disorders. Based on these findings, the risk of ASD in the offspring should not be a consideration to withhold treatment with commonly used antidepressant drugs from pregnant women.

Association of Antidepressant Medication Use During Pregnancy With Intellectual Disability in Offspring

IMPORTANCE

Maternal antidepressant medication use during pregnancy has previously been associated with adverse outcomes in offspring, but to our knowledge, the association with intellectual disability (ID) has not been investigated.

OBJECTIVES

To examine the association of maternal antidepressant medication use during pregnancy with ID in offspring and investigate the importance of parental mental illness for such an association.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study of 179 007 children born from January 1, 2006, through December 31, 2007, with complete parental information from national registers who were followed up from birth throughout 2014.

MAIN OUTCOMES AND MEASURES

We estimated relative risks (RRs) and 95% CIs of ID in children exposed during pregnancy to any antidepressant medication or specifically to selective serotonin reuptake inhibitor (SSRI) antidepressants, all other non-SSRI antidepressants, or other nonantidepressant psychotropic medications. Analyses were adjusted for potential confounders. In addition to full population analyses, we used a subsample to compare mothers who used antidepressants during pregnancy with mothers who had at least one diagnosis of depression or anxiety before childbirth but did not use antidepressants during pregnancy.

RESULTS

Of the 179 007 children included in the study (mean [SD] age at end of follow-up, 7.9 [0.6] years; 92 133 [51.5%] male and 86 874 [48.5%] female), ID was diagnosed in 37 children (0.9%) exposed to antidepressants and in 819 children (0.5%) unexposed to antidepressants. With adjustment for potential confounders, the RR of ID after antidepressant exposure was estimated at 1.33 (95% CI, 0.90-1.98) in the full population sample and 1.64 (95% CI, 0.95-2.83) in the subsample of women with depression. Results from analyses of SSRI antidepressants, non-SSRI antidepressants, and nonantidepressant psychotropic medications and analyses in the clinically relevant subsample did not deviate from the full-sample results.

CONCLUSIONS AND RELEVANCE

The unadjusted RR of ID was increased in offspring born to mothers treated with antidepressants during pregnancy. After adjustment for confounding factors, however, the current study did not find evidence of an association between ID and maternal antidepressant medication use during pregnancy. Instead, the association may be attributable to a mechanism integral to other factors, such as parental age and mother's psychiatric disorder.

Neonatal and regressive forms of autism: Diseases with similar symptoms but a different etiology

Autistic Spectrum Disorder (ASD) can be a debilitating, life-long neurocognitive disease. ASD is caused by genetic and epigenetic factors and largely unknown and poorly understood environmental triggers. Signs and symptoms of ASD often appear in the first year of life while the disease strikes other infants who had previously been developing normally at around 2years of age. Ozonoff and her colleagues recently suggested that there are three different pathways or trajectories for the development of ASD in infants 6-24months of age. I hypothesize that pathway 1 is caused by in utero insult/injury, pathway 2 by obstetric complications at birth, and pathway 3 by environmental triggers of ASD affecting infants 0-3years of age. Faster progress can be made in elucidating the underlying causes of neonatal and regressive forms of ASD if the diseases are investigated separately, instead of being part of the same disorder.

Antidepressant use during pregnancy and psychiatric disorders in offspring: Danish nationwide register based cohort study

Objective To investigate the association between in utero exposure to antidepressants and risk of psychiatric disorders.Design Population based cohort study.Setting Danish national registers.Participants 905 383 liveborn singletons born during 1998-2012 in Denmark and followed from birth until July 2014, death, emigration, or date of first psychiatric diagnosis, whichever came first. The children were followed for a maximum of 16.5 years and contributed 8.1×10⁶ person years at risk.Exposures for observational studies Children were categorised into four groups according to maternal antidepressant use within two years before and during pregnancy: unexposed, antidepressant discontinuation (use before but not during pregnancy), antidepressant continuation (use both before and during pregnancy), and new user (use only during pregnancy).Main outcome measure First psychiatric diagnosis in children, defined as first day of inpatient or outpatient treatment for psychiatric disorders. Hazard ratios of psychiatric disorders were estimated using Cox regression models.Results Overall, psychiatric disorders were diagnosed in 32 400 children. The adjusted 15 year cumulative incidence of psychiatric disorders was 8.0% (95% confidence interval 7.9% to 8.2%) in the unexposed group, 11.5% (10.3% to 12.9%) in the antidepressant discontinuation group, 13.6% (11.3% to 16.3%) in the continuation group, and 14.5% (10.5% to 19.8%) in the new user group. The antidepressant continuation group had an increased risk of psychiatric disorders (hazard ratio 1.27, 1.17 to 1.38), compared with the discontinuation group.Conclusions In utero exposure to antidepressants was associated with increased risk of psychiatric disorders. The association may be attributable to the severity of underlying maternal disorders in combination with antidepressant exposure in utero. The findings suggest that focusing solely on a single psychiatric disorder among offspring in studies of in utero antidepressant exposure may be too restrictive.

Maternal SSRI discontinuation, use, psychiatric disorder and the risk of autism in children: a meta-analysis of cohort studies

We undertook an exclusive meta-analysis of cohort studies investigating the possible link between prenatal selective serotonin reuptake inhibitor (SSRI) exposure and autism spectrum disorders (ASD) in children to further investigate our previous suggestion of confounding by indication. The point estimates regarding the following cohorts were extracted and pooled: (1) pregnant women who discontinued SSRI until 3 months before pregnancy; (2) pregnant women who were exposed to SSRI during pregnancy; and (3) pregnant women with maternal psychiatric disorder but no exposure to SSRI during pregnancy. Although the pooled point estimate of the first cohort showed a trend for increase, it did not reach significance. The pooled point estimates of the latter cohorts showed a significant association with ASD which strengthens our previous suggestion of confounding by indication. Future studies should be adequately designed to differentiate whether the previously suggested association is a result of maternal psychiatric disorder or SSRI exposure or both.

Links between serotonin reuptake inhibition during pregnancy and neurodevelopmental delay/spectrum disorders: A systematic review of epidemiological and physiological evidence

OBJECTIVE

To investigate possible linkages between neurodevelopmental delay and neurodevelopmental spectrum disorders and exposure to medication with effects on serotonin reuptake inhibition during pregnancy.

METHODS

We systematically reviewed the epidemiological literature for studies bearing on this relationship in children born with neurodevelopmental spectrum disorder and related conditions, as well as animal studies giving serotonin reuptake inhibitors to pregnant animals and in addition reviewed the literature for proposals as to possible mechanisms that might link effects on serotonin reuptake with cognitive changes post-partum.The epidemiological studies were analysed to produce Forest plots to illustrate possible relations.

RESULTS

The odds ratio of Autistic Spectrum or related Disorders in children born to women taking serotonin reuptake inhibiting antidepressants during pregnancy in case control studies was 1.95 (95% C.I. 1.63, 2.34) and in prospective cohort studies was 1.96 (95% C.I. 1.33, 2.90).

CONCLUSIONS

There appears to be a link between serotonin reuptake inhibition in pregnancy and developmental delay and spectrum disorders in infancy leading to cognitive difficulties in childhood. More work needs to be done to establish more precisely the nature of the difficulties and possible mechanisms through which this link might be mediated.

Antidepressants during pregnancy and autism in offspring: population based cohort study

Objectives To study the association between maternal use of antidepressants during pregnancy and autism spectrum disorder (ASD) in offspring.Design Observational prospective cohort study with regression methods, propensity score matching, sibling controls, and negative control comparison.Setting Stockholm County, Sweden.Participants 254 610 individuals aged 4-17, including 5378 with autism, living in Stockholm County in 2001-11 who were born to mothers who did not take antidepressants and did not have any psychiatric disorder, mothers who took antidepressants during pregnancy, or mothers with psychiatric disorders who did not take antidepressants during pregnancy. Maternal antidepressant use was recorded during first antenatal interview or determined from prescription records.Main outcome measure Offspring diagnosis of autism spectrum disorder, with and without intellectual disability.Results Of the 3342 children exposed to antidepressants during pregnancy, 4.1% (n=136) had a diagnosis of autism compared with a 2.9% prevalence (n=353) in 12 325 children not exposed to antidepressants whose mothers had a history of a psychiatric disorder (adjusted odds ratio 1.45, 95% confidence interval 1.13 to 1.85). Propensity score analysis led to similar results. The results of a sibling control analysis were in the same direction, although with wider confidence intervals. In a negative control comparison, there was no evidence of any increased risk of autism in children whose fathers were prescribed antidepressants during the mothers' pregnancy (1.13, 0.68 to 1.88). In all analyses, the risk increase concerned only autism without intellectual disability.Conclusions The association between antidepressant use during pregnancy and autism, particularly autism without intellectual disability, might not solely be a byproduct of confounding. Study of the potential underlying biological mechanisms could help the understanding of modifiable mechanisms in the aetiology of autism. Importantly, the absolute risk of autism was small, and, hypothetically, if no pregnant women took antidepressants, the number of cases that could potentially be prevented would be small.