Psychiatric sequelae of low birth weight at 6 years of age

The association of serum levels of zinc and vitamin D with wasting among Iranian pre-school children

PURPOSE

Wasting is a main indicator of Child's undernutrition that is associated with several non-communicable diseases and child mortality. This is the first population-based study which evaluated the association of serum zinc and vitamin D levels with wasting in a Middle East region. We also reported the prevalence of vitamin D and zinc deficiencies among Iranian pre-school children aged 6 years.

METHODS

This was a multicenter cross-sectional study that included 425 children aged between 5 and 7 years (on average 6 years) with BMI-for-age Z-scores of < - 1 SD resident in urban and rural areas of Iran in the spring of 2012 as part of the National Integrated Micronutrient Survey 2 (NIMS-2). Anthropometric measurements and blood sampling were obtained. The prevalence of vitamin D and zinc deficiencies together with the correlations of these variables with the increase of BMI-for-age Z-scores were evaluated.

RESULTS

The prevalence of vitamin D and zinc deficiencies was 18.8% and 12.7%, respectively. In addition, 31.1% of children were wasted. Children in the second tertile of 25(OH)D levels were less likely to have wasting compared with those in the first tertile in both crude and adjusted models (OR 0.47, 95% CI 0.27-0.83). A significant inverse association was found between serum levels of zinc and wasting (OR 0.57, 95% CI 0.34-0.96); such that after adjusting for confounders, children in the highest tertile of serum zinc had 47% less odds of wasting compared with those in the first tertile (OR 0.53, 95% CI 0.31-0.91).

CONCLUSION

The prevalence of vitamin D and zinc deficiencies among Iranian pre-school children aged 6 years was 18.8 and 12.7%, respectively. Serum levels of vitamin D and zinc were inversely associated with wasting either before or after controlling for confounders.

LEVEL OF EVIDENCE

Level III, case-control analytic studies.

Prenatal and perinatal risk factors for anxiety disorders among children and adolescents: A systematic review

BACKGROUND

Prenatal and perinatal risk factors for anxiety disorders have rarely been studied, even though they are highly prevalent in children and adolescents. It is important to identify the common risk factors, so that targeted preventive care and early interventions can be provided.

METHODS

A systematic review of the PubMed and PsycInfo databases was conducted to 25 October 2019, according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses guidelines. The protocol was registered on the Prospective Register of Systematic Reviews and the quality assessment was carried out using the Joanna Briggs tools.

RESULTS

The review identified 31 studies from eight countries, including three register studies. Cohort sizes ranged from 69 to 89,404 and diagnoses cases ranged from 4 to 7867. Although various risk factors had been researched, only few of them had been repeatedly studied and the findings were highly inconsistent. The associations between the different risk factors and anxiety disorders seemed weak compared to many other psychiatric disorders, but preterm birth and maternal somatic illnesses may increase the risk for anxiety disorders in offspring.

LIMITATIONS

The studies varied considerably by study design, risk factors and anxiety disorders studied, sample sizes and follow up periods.

CONCLUSIONS

Prenatal and perinatal risk factors for anxiety disorders have been under-researched, compared to other psychiatric disorders. Our systematic review found weak links to prenatal events, but flagged up preterm birth and maternal somatic illnesses as possible avenues for future research.

Association of mental health problems in childhood with prenatal and postnatal physical growth

Aims

The present study was conducted to examine (i) prenatal and postnatal patterns of growth in relation to the risk of later mental health problems in children and (ii) the possible mediating effect of these patterns of growth in the association between parental socioeconomic status (SES) and children’s mental health.

Subjects and methods

The present study is part of a blinded, matched case control study, involving a retrospective analysis of prospectively collected data from routine examinations at community health services for children and adolescents. The sample comprised 80 patients, referred between the age of 6–13 years to the Community Mental Health Centre in Maastricht, and 320 matched population controls.

Results

Children coming from unemployed families weighed less at birth, but postnatal growth was not associated with this or other indicators of SES. Although children using mental health care were somewhat smaller at birth, there was no evidence that leanness during childhood was a risk factor for the development of mental health problems.

Conclusions

The present results showed some evidence for the impact of intrauterine development on children’s mental health problems. In addition, neither prenatal nor postnatal physical growth were on the pathway between parental SES and children’s mental health problems.

The role of birth weight on the causal pathway to child and adolescent ADHD symptomatology: a population-based twin differences longitudinal design

BACKGROUND

Available evidence points towards lower birth weight as a risk factor for the development of attention deficit/hyperactivity disorder (ADHD) symptoms. We probed the causal nature of this putative effect of birth weight on ADHD symptoms using the twin differences design, which accounts for genetic and shared environmental confounds.

METHOD

In a large population-based twin sample - 3,499 monozygotic (MZ) and 6,698 dizygotic (DZ) pairs - parents, teachers or twins rated the twins' ADHD symptoms at nine assessment waves (2-16 years). We implemented the twin differences design, which completely accounts for shared environmental and genetic confounding in MZ twins. We tested whether: (a) the lighter-born twins had elevated ADHD symptoms compared to the heavier-born twins, by regressing within-pair differences of ADHD symptoms on within-pair differences of birth weight among MZ twins; (b) the effect of birth weight on ADHD was moderated by gender, gestational age and low birth weight; (c) this effect changed with age at ADHD assessment using adapted latent growth curve models; and (d) results differed for inattention and hyperactivity/impulsivity.

RESULTS

Birth weight significantly predicted ADHD symptoms from early childhood to late adolescence. The lighter-born twin had more ADHD symptoms than the heavier-born cotwin among MZ twins across assessment waves and raters. No moderation effect was detected. The magnitude of the effect of birth weight decreased significantly across time for hyperactivity/impulsivity, but the decrease failed to reach significance for inattention. Estimates for inattention were significantly larger than for hyperactivity/impulsivity at each time point, implying stronger effect of birth weight on inattention symptoms.

CONCLUSIONS

Our findings provide stringent evidence for environmental effect of lower birth weight on the causal pathway to elevated ADHD symptoms. Effect of birth weight persists across a 14-year period from childhood into late adolescence, in particular for inattention symptoms.

A Meta-Analysis of the Association Between Birth Weight and Attention Deficit Hyperactivity Disorder

A large body of work has investigated the association between birth weight and ADHD and has resulted in mixed findings with regard to the direction and magnitude of this association. Despite the vast amount of research on this topic, a comprehensive and systematic quantification of the association between birth weight and ADHD has yet to be undertaken. A meta-analysis of 88 unique studies (N = 4,645,482) was conducted to quantify the overall effect size of birth weight on ADHD symptoms. Several variables were examined as moderators that may contribute to systematic variation in effect sizes. Overall, birth weight was found to have a small, but significant, association with ADHD symptoms such that individuals born at lower birth weights manifested greater symptoms of ADHD (r = -0.15). Sample type, mean birth weight of the sample, geographic region, the informant of ADHD symptoms, ADHD symptom measurement method, and race were all found to contribute significantly to heterogeneity in effect sizes. Notably, several early life risk factors previously found to be associated with both ADHD and birth weight, gestational age and prenatal smoking exposure, were not found to contribute to heterogeneity in effect sizes. The findings of the current analyses align with the growing recognition that early life adversity contributes to neurodevelopmental difficulties, and the findings highlight the importance of a better understanding of the mechanisms underlying the association between early life risk factors and adverse neurodevelopmental sequela, such as that observed in ADHD.

Research Review: The role of obstetric and neonatal complications in childhood attention deficit and hyperactivity disorder - a systematic review

BACKGROUND

Attention deficit and hyperactivity disorder (ADHD) is a developmental disorder characterized by an inability to sustain attention, activity levels and impulse control, and, according to the latest studies, the prevalence is about 8% and in some countries less than 1%. Currently, it is well-known that complications during the perinatal period have significant implications on child's physical and mental health. Purpose of the present paper is to review the literature about the association between perinatal complications and future risk of an ADHD diagnosis.

METHODS

A research in the main database sources has been conducted to obtain a systematic review on the perinatal risk factors of ADHD.

RESULTS

Among perinatal complications, available data indicate low birth weight (LBW) (Cohen's d effect size range: 0.31-1.64-small effect size) and preterm birth (PB) (range d: 0.41-0.68) as the most important factors associated with a future diagnosis of ADHD.

CONCLUSIONS

PB and LBW children should be carefully monitored for an early diagnosis of ADHD limiting the impact of the disease in life span. A systematic review focusing on these risk factors have not been published until now, in the next future preventive strategies should be developed in order to minimize ADHD onset.

Does the Environment Have an Enduring Effect on ADHD? A Longitudinal Study of Monozygotic Twin Differences in Children

Environmental factors play a key role in the development of Attention-Deficit/Hyperactivity Disorder (ADHD), but the long-term effects of these factors are still unclear. This study analyses data from 1024 monozygotic (identical) twins in Australia, the United States, and Scandinavia who were assessed for ADHD in Preschool, Kindergarten, Grade 1, and Grade 2. Differences within each twin pair were used as a direct measure of non-shared environmental effects. The Trait-State-Occasion (TSO) model developed by Cole et al. (Psychological Methods, 10, 3-20, 2005) was used to separate the non-shared environmental effects into stable factors, and transient factors that excluded measurement error. Stable factors explained, on average, 44 % and 39 % of the environmental variance in hyperactive-impulsive and inattentive symptoms, respectively. Transient effects explained the remaining 56 % and 60 % of variance. The proportion of stable variance was higher than expected based on previous research, suggesting promise for targeted interventions if future research identifies these stable risk factors.

Sex moderates the impact of birth weight on child externalizing psychopathology

Low birth weight (LBW) has consistently been associated with childhood attention deficit/hyperactivity disorder (ADHD), and a similar association has been found for childhood externalizing disorders, such as oppositional defiant disorder (ODD) and conduct disorder (CD), albeit to a lesser degree. Although the association between LBW and these disorders has been robustly replicated, few studies have adequately controlled for confounding variables, such as parental age at birth and prenatal tobacco use, examined the specificity of the risk of LBW for ADHD symptoms, or investigated potential nonlinear (i.e., quadratic) effects of birth weight (BW). Additionally, the extent to which LBW confers risk for these disorders depending on childhood sex has rarely been examined. The current study examined associations between BW and ADHD, ODD, and CD symptom dimensions as well as the extent to which such associations are moderated by child sex, while also controlling for confounding variables. Significant interactions between sex and BW emerged across all analyses predicting ADHD and externalizing psychopathology, such that associations were stronger in males relative to females. Results remained when controlling for a number of confounds, including parental age, prenatal tobacco use, comorbid psychopathology, as well as other indicators of maternal and child health during the pre- and perinatal period. Both linear and quadratic associations emerged between BW and both hyperactivity and CD symptoms, whereas BW predicted inattention and ODD symptoms in a linear fashion. Future research should continue to investigate the impact of BW on ADHD and externalizing psychopathology, in particular, the biological mechanisms underlying this association. (PsycINFO Database Record

Pre- and perinatal complications in relation to Tourette syndrome and co-occurring obsessive-compulsive disorder and attention-deficit/hyperactivity disorder

Pre- and perinatal complications have been implicated in the onset and clinical expression of Tourette syndrome albeit with considerable inconsistencies across studies. Also, little is known about their role in co-occurring obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD) in individuals with a tic disorder. Therefore, we aimed to investigate the role of pre- and perinatal complications in relation to the presence and symptom severity of chronic tic disorder and co-occurring OCD and ADHD using data of 1113 participants from the Tourette International Collaborative Genetics study. This study included 586 participants with a chronic tic disorder and 527 unaffected family controls. We controlled for age and sex differences by creating propensity score matched subsamples for both case-control and within-case analyses. We found that premature birth (OR = 1.72) and morning sickness requiring medical attention (OR = 2.57) were associated with the presence of a chronic tic disorder. Also, the total number of pre- and perinatal complications was higher in those with a tic disorder (OR = 1.07). Furthermore, neonatal complications were related to the presence (OR = 1.46) and severity (b = 2.27) of co-occurring OCD and also to ADHD severity (b = 1.09). Delivery complications were only related to co-occurring OCD (OR = 1.49). We conclude that early exposure to adverse situations during pregnancy is related to the presence of chronic tic disorders. Exposure at a later stage, at birth or during the first weeks of life, appears to be associated with co-occurring OCD and ADHD.

Links between motor control and classroom behaviors: Moderation by low birth weight

It is unclear from past research on effortful control whether one of its components, motor control, independently contributes to adaptive classroom behaviors. The goal of this study was to identify associations between early motor control, measured by the walk-a-line task at age 3, and teacher-reported learning-related behaviors (approaches to learning and attention problems) and behavior problems in kindergarten classrooms. Models tested whether children who were vulnerable to poorer learning behaviors and more behavior problems due to having been born low birth weight benefited more, less, or the same as other children from better motor control. Data were drawn from the national Fragile Families and Child-Wellbeing Study (n = 751). Regression models indicated that motor control was significantly associated with better approaches to learning and fewer behavior problems. Children who were low birth weight benefitted more than normal birth weight children from better motor control with respect to their approaches to learning, but equally with respect to behavior problems. Additionally, for low but not normal birth weight children, better motor control predicted fewer attention problems. These findings suggest that motor control follows a compensatory model of development for low birth weight children and classroom behaviors.

Estimating the Roles of Genetic Risk, Perinatal Risk, and Marital Hostility on Early Childhood Adjustment: Medical Records and Self-Reports

A wide variety of perinatal risk factors have been linked to later developmental outcomes in children. Much of this work has relied on either birth/medical records or mothers' self-reports collected after delivery, and there has been an ongoing debate about which strategy provides the most accurate and reliable data. This report uses a parent-offspring adoption design (N = 561 families) to (1) examine the correspondence between medical record data and self-report data, (2) examine how perinatal risk factors may influence child internalizing and externalizing behavior at age 4.5 years, and (3) explore interactions among genetic, perinatal risk, and rearing environment on child internalizing and externalizing behavior during early childhood. The agreement of self-reports and medical records data was relatively high (51-100 %), although there was some variation based on the construct. There were few main effects of perinatal risk on child outcomes; however, there were several 2- and 3-way interactions suggesting that the combined influences of genetic, perinatal, and rearing environmental risks are important, particularly for predicting whether children exhibit internalizing versus externalizing symptoms at age 4.5 years.

Eating disorder psychopathology, brain structure, neuropsychological correlates and risk mechanisms in very preterm young adults

This study investigates the prevalence of eating disorder (ED) psychopathology, neuropsychological function, structural brain correlates and risk mechanisms in a prospective cohort of very preterm (VPT) young adults. We assessed ED psychopathology and neuropsychological correlates in 143 cohort individuals born at <33 weeks of gestation. Structural brain correlates and risk factors at birth, in childhood and adolescence, were investigated using prospectively collected data throughout childhood/adolescence. VPT-born individuals had high levels of ED psychopathology at age 21 years. Executive function did not correlate with ED symptomatology. VPT adults presenting with ED psychopathology had smaller grey matter volume at age 14/15 years in the left posterior cerebellum and smaller white matter volume in the fusiform gyrus bilaterally, compared with VPT adults with no ED psychopathology. Caesarean delivery predicted engaging in compensatory behaviours, and severe eating difficulty at age 14 years predicted ED symptomatology in young adulthood. VPT individuals are at risk for ED symptomatology, with evidence of associated structural alterations in posterior brain regions. Further prospective studies are needed to clarify the pathways that lead from perinatal/obstetric complications to ED and relevant neurobiological mechanisms. © 2015 The Authors. European Eating Disorders Review published by John Wiley &Sons, Ltd.

Prenatal glucocorticoid exposure in rats: programming effects on stress reactivity and cognition in adult offspring

Human epidemiological studies have provided compelling evidence that prenatal exposure to stress is associated with significantly increased risks of developing psychiatric disorders in adulthood. Exposure to excessive maternal glucocorticoids may underlie this fetal programming effect. In the current study, we assessed how prenatal dexamethasone administration during the last week of gestation affects stress reactivity and cognition in adult offspring. Stress reactivity was assessed by evaluating anxiety-like behavior on an elevated plus maze and in an open field. In addition, to characterize the long-term cognitive outcomes of prenatal exposure to glucocorticoids, animals were assessed on two cognitive tasks, a spatial reference memory task with reversal learning and a delayed matching to position (DMTP) task. Our results suggest that prenatal exposure to dexamethasone had no observable effect on anxiety-like behavior, but affected cognition in the adult offspring. Prenatally dexamethasone-exposed animals showed a transient deficit in the spatial reference memory task and a trend to faster acquisition during the reversal-learning phase. Furthermore, prenatally dexamethasone-treated animals also showed faster learning of new platform positions in the DMTP task. These results suggest that fetal overexposure to glucocorticoids programs a phenotype characterized by cognitive flexibility and adaptability to frequent changes in environmental circumstances. This can be viewed as an attempt to increase the fitness of survival in a potentially hazardous postnatal environment, as predicted by intrauterine adversity. Collectively, our data suggest that prenatal exposure to dexamethasone in rats could be used as an animal model for studying some cognitive components of related psychiatric disorders.

Angiogenic, neurotrophic, and inflammatory system SNPs moderate the association between birth weight and ADHD symptom severity

Low birth weight is associated with increased risk for Attention-Deficit/Hyperactivity Disorder (ADHD); however, the etiological underpinnings of this relationship remain unclear. This study investigated if genetic variants in angiogenic, dopaminergic, neurotrophic, kynurenine, and cytokine-related biological pathways moderate the relationship between birth weight and ADHD symptom severity. A total of 398 youth from two multi-site, family-based studies of ADHD were included in the analysis. The sample consisted of 360 ADHD probands, 21 affected siblings, and 17 unaffected siblings. A set of 164 SNPs from 31 candidate genes, representing five biological pathways, were included in our analyses. Birth weight and gestational age data were collected from a state birth registry, medical records, and parent report. Generalized Estimating Equations tested for main effects and interactions between individual SNPs and birth weight centile in predicting ADHD symptom severity. SNPs within neurotrophic (NTRK3) and cytokine genes (CNTFR) were associated with ADHD inattentive symptom severity. There was no main effect of birth weight centile on ADHD symptom severity. SNPs within angiogenic (NRP1 & NRP2), neurotrophic (NTRK1 & NTRK3), cytokine (IL16 & S100B), and kynurenine (CCBL1 & CCBL2) genes moderate the association between birth weight centile and ADHD symptom severity. The SNP main effects and SNP × birth weight centile interactions remained significant after adjusting for multiple testing. Genetic variability in angiogenic, neurotrophic, and inflammatory systems may moderate the association between restricted prenatal growth, a proxy for an adverse prenatal environment, and risk to develop ADHD.

Neurodevelopmental outcomes of moderately preterm birth: precursors of attention deficit hyperactivity disorder at preschool age

Moderately preterm birth seems to be an evolutional risk condition at cognitive, behavioural and socio-relational levels. The study is aimed to investigate the likely occurrence of precursors of Attention Deficit Hyperactivity Disorder (ADHD) in moderately preterm children at preschool age. The research involved an experimental group made up of 50 moderately preterm children (mean: 34.6 weeks' gestational age, standard deviation [SD]: 2) without any medical and neurologic neonatal complications and low birth weight (mean:2100g., SD: 350g.) and a check group of 50 full term born children. Parents and teachers of children were administered specific questionnaires to detect ADHD. The outcomes show a risk of ADHD highlighting statically significant differences related to gender [F(2, 99) = 2.99, p = .04], birth [F(2, 99) = 9.6, p = .03] and interaction [F(2, 99) = 2.2, p = .01]. The moderately preterm children showed deficit in self-regulation [F(2, 99) = 1.14, p = .04] and attention deficit in daily life both in family [F(2, 99) = 7.8, p = .04] and school contexts [F(1, 99) = 3.3, p = .04]. The outcomes hint assessment paths aimed to monitor the aspects of cognitive, motor, behavioural development of moderately preterm children recognised as signs of problematic functioning profiles. Therefore, specific training will have been designed since preschool age in order to control the ADHD risk factors.

Assessing interchangeability at cluster levels with multiple-informant data

Studies examining the relationship between neighborhood social disorder and health often rely on multiple informants. Such studies assume interchangeability of the latent constructs derived from multiple-informant data. Existing methods examining this assumption do not clearly delineate the uncertainty at individual levels from that at neighborhood levels. We propose a multilevel variance component factor model that allows this delineation. Data come from a survey of a representative sample of children born between 1983 and 1985 in the inner city of Detroit and nearby middle-class suburbs. Results indicate that the informant-level models tend to exaggerate the effect of places because of differences between persons. Our evaluations of different methodologies lead to the recommendation of the multilevel variance component factor model whenever multiple-informant reports can be aggregated at a neighborhood level.

Disruptive behaviour disorders: a systematic review of environmental antenatal and early years risk factors

Disruptive behaviour disorders (DBDs), including attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD) and conduct disorder (CD) are chronic disorders with significant overlap in aetiology and presentation. An integrative examination of environmental risk factors is lacking. Six literature searches of web-based bibliographic databases were completed to identify literature on DBDs in general and five disorders in particular: CD, ODD, ADHD, deficits of attention, motor control and perception, and reactive attachment disorder. Searches were filtered to focus on studies including diagnostic assessment, focussing on environmental risk and protective factors in the first 4 years of life. The database searches generated 9806 papers of which 47 were reviewed after filters had been applied. The evidence suggests links between a number of early life risk factors and DBDs, including prenatal cigarette smoking and alcohol use, prenatal viral illness, maternal stress and anxiety, low birthweight, peri-partum and early neonatal complications, parental stress and parenting styles in infancy, early deprivation, adoption and separation. Despite the understanding that there is sharing of risk factors between the DBDs, there has been a disproportionate focus on the role of certain risk factors at the expense of others and the field is weakened by difficulties in controlling for all potential confounding variables.

Parental monitoring at age 11 and subsequent onset of cannabis use up to age 17: results from a prospective study

OBJECTIVE

Smoking cannabis before adulthood is associated with subsequent adverse psychiatric outcomes and might be prevented via parenting interventions such as programs to increase parents' effective monitoring of their children. The aim of this study was to estimate the influence of parental monitoring assessed at age 11 on the initiation of cannabis use before age 18.

METHOD

Data are from a longitudinal study of 823 children randomly selected from 1983 to 1985 newborn discharge lists from two major hospitals in southeast Michigan. Parental monitoring was assessed at age 11 via a standardized 10-item scale, and the parental monitoring-cannabis initiation relationship was estimated for the 638 children with complete data. Poisson regression with robust error variances was used to estimate the association that links levels of parental monitoring at age 11 with the risk of cannabis use up to age 17, adjusting for other important covariates.

RESULTS

Higher levels of parental monitoring at age 11 were associated with a reduced risk of cannabis initiation from ages 11 to 17 (adjusted estimated relative risk = 0.96; 95% CI [0.93, 0.98]).

CONCLUSIONS

This prospective investigation found that higher levels of parental monitoring were associated with a reduced occurrence of cannabis initiation from ages 11 to 17 years. Consistent with evidence reported elsewhere, these findings from prospective research lend further support to theories about parenting and familial characteristics that might exert long-lasting influences on a child's risk of starting to use drugs.

Executive functions of six-year-old boys with normal birth weight and gestational age

Impaired fetal development, reflected by low birth weight or prematurity, predicts an increased risk for psychopathology, especially attention deficit hyperactivity disorder (ADHD). Such effects cut across the normal range of birth weight and gestation. Despite the strength of existing epidemiological data, cognitive pathways that link fetal development to mental health are largely unknown. In this study we examined the relation of birth weight (>2500 g) and gestational age (37-41 weeks) within the normal range with specific executive functions in 195 Singaporean six-year-old boys of Chinese ethnicity. Birth weight adjusted for gestational age was used as indicator of fetal growth while gestational age was indicative of fetal maturity. Linear regression revealed that increased fetal growth within the normal range is associated with an improved ability to learn rules during the intra/extra-dimensional shift task and to retain visual information for short period of time during the delayed matching to sample task. Moreover, faster and consistent reaction times during the stop-signal task were observed among boys born at term, but with higher gestational age. Hence, even among boys born at term with normal birth weight, variations in fetal growth and maturity showed distinct effects on specific executive functions.

Atypical social development in neonatal intensive care unit survivors at 12 months

BACKGROUND

Owing to advances in neonatal intensive care, many infants who are hospitalized in neonatal intensive care units (NICU) can survive and grow, and are referred to as NICU survivors. However, social development in NICU survivors has not been fully explored.

METHODS

To examine the social development of NICU survivors, a questionnaire consisting of the Modified Checklist for Autism in Toddlers (M-CHAT) was used. The M-CHAT was completed by the parents of either NICU survivors (n= 117) or normally delivered children (control group, n= 112) during their regular medical checkups at a corrected age of 12 months.

RESULTS

Ninety percent of NICU survivors and 63% of control children did not pass the M-CHAT screen. As it was originally designed for children aged 18-30 months, failed M-CHAT items could have been due to developmental issues and not due to autistic spectrum disorders. However, there was a significant difference in the total number of items failed between the two groups. In particular, many NICU survivors did not pass on M-CHAT items, such as oversensitivity to noise, unusual finger movements, and attempts to attract attention. Concerning perinatal complications, infants with low birthweight and/or the need for respiratory support tended to have a higher number of failures on all M-CHAT items.

CONCLUSIONS

NICU survivors may have distinct developmental patterns of social communication, and should be followed up for assessment of social skills and neurological development.

Prevalence of psychiatric diagnoses in preterm and full-term children, adolescents and young adults: a meta-analysis

BACKGROUND

Preterm (PT) birth and low birth weight (LBW) are high-prevalence events that are associated with adverse outcomes in the longer term, with vulnerability increasing as maturity at birth decreases. Psychiatric symptomatology appears heightened in PT/LBW survivors, though there are some discordant findings from studies using questionnaire measures, particularly with respect to anxiety and depressive symptoms.

METHOD

This article synthesises findings from research using clinical psychiatric diagnostic criteria in PT/LBW individuals aged 10-25 years compared with term-born peers. Key outcomes of interest were the rates of individuals receiving any psychiatric diagnosis and the number of diagnoses of anxiety or depressive disorders.

RESULTS

A literature search for studies reporting prevalence of 'any diagnosis' yielded five studies that met inclusion criteria, with a total of 565 PT/LBW and 533 control individuals. Also, five studies were found that reported rates of anxiety/depression (692 PT/LBW and 605 control individuals). The risk of these outcomes was increased for PT/LBW individuals compared with controls [any diagnosis: odds ratio (OR) 3.66, 95% confidence interval (CI) 2.57-5.21; anxiety or depressive disorder: OR 2.86, 95% CI 1.73-4.73].

CONCLUSIONS

The studies reviewed here indicate that, in addition to monitoring and management of medical and cognitive sequelae, the psychological well-being of PT/LBW individuals should be a key part of ongoing care.

The role of imprinted genes in mediating susceptibility to neuropsychiatric disorders

Imprinted genes, which are thought to comprise <1% of the mammalian genome, are defined by their parent-of-origin specific monoallelic expression arising as a consequence of differential epigenetic marking of alleles in the paternal and maternal germlines. Such genes are highly represented in the brain and placental transcriptomes, and have been shown to exert significant influence on fundamental developmental processes in these organs. Converging evidence from work in man and animal models has shown that imprinted genes can influence a variety of brain and behavioral endophenotypes. In this article, we review the current evidence that imprinted gene dysfunction is associated with vulnerability to several common psychiatric disorders. We also discuss how studying imprinted gene (dys)function may provide mechanistic insights into two important areas in modern psychiatry: first, how environmental factors (especially in utero) interact with genetic liability via epigenetic mechanisms to predispose to later mental illness, and second, the molecular underpinnings of sex-specific vulnerability to psychiatric disorders.

Behavior problems at ages 6 and 11 and high school academic achievement: longitudinal latent variable modeling

Previous studies documented long-run effects of behavior problems at the start of school on academic achievement. However, these studies did not examine whether the observed effects of early behavior problems are explained by more proximate behavior problems, given the tendency of children's behavior problems to persist. Latent variable modeling was applied to estimate the effects of behavior problems at ages 6 and 11 on academic achievement at age 17, using data from a longitudinal study (n=823). Behavior problems at ages 6 and 11, each stage independently of the other, predicted lower math and reading test scores at age 17, controlling for intelligence quotient (IQ), birth weight, maternal characteristics, family and community environment, and taking into account behavior problems at age 17. Behavior problems at the start of school, independent of later behavior problems, exert lingering effects on achievement by impeding the acquisition of cognitive skills that are the foundation for later academic progress.

Prenatal growth, postnatal growth and trait anxiety in late adulthood - the Helsinki Birth Cohort Study

OBJECTIVE

Trait anxiety may predispose to anxiety disorders and cardiovascular events. We tested whether prenatal growth or postnatal growth from birth to 11 years of age and in adulthood predict trait anxiety in late adulthood.

METHOD

Women (n = 951) and men (n = 753) reported trait anxiety using the Spielberger Trait Anxiety Scale at an average age of 63.4 years and growth was estimated from records.

RESULTS

Higher trait anxiety was predicted by smaller body size at birth, in infancy and in adulthood. Moreover, faster growth particularly from seven to 11 years of age and slower growth between 11 and 63 years predicted higher trait anxiety.

CONCLUSION

We found a pattern of pre- and postnatal growth that predisposed to higher trait anxiety in late adulthood. This pattern resembles that found to increase the risk of cardiovascular events and, thus, points to a shared common origin in a suboptimal prenatal and childhood developmental milieu.

Predictors of specific phobia in young women: a prospective community study

Potential predictors of incidence of specific phobia were investigated within the conceptual framework of the vulnerability-stress model. At two time points separated by approximately 17 months, a community sample of 1261 German women (18-25 years of age) completed a structured interview. A broad range of potential stress- and vulnerability-related predictors was recorded at initial assessment. The strongest predictors of incidence were: high levels of preexisting psychopathology, a lack of coping skills, and a negative cognitive style. Assessing individual differences in stress and vulnerability thus seem to offer additional information about etiology of specific phobia beyond traditional learning theory. Incorporating the role of these risk factors may be useful for identifying individuals who are at increased risk and improving measures of prevention.

Parental monitoring at age 11 and smoking initiation up to age 17 among Blacks and Whites: a prospective investigation

INTRODUCTION

Parental monitoring has been identified as a predictor of adolescent smoking initiation. However, it is uncertain if the association is uniform across different racial groups.

METHODS

Random samples of low birth-weight and normal birth-weight children were drawn from newborn discharge lists (1983-1985) of two major hospitals in southeast Michigan, one serving an inner city and the other serving suburbs. Assessments occurred at ages 6, 11, and 17 years. Statistical analysis was conducted on children with data on parent monitoring at age 11 and tobacco use at age 17 who had never smoked a cigarette up to age 11 (n = 572). Multiple logistic regression was used to examine the association between parent monitoring and children's smoking initiation. Two-way interactions were tested.

RESULTS

The relationship between parent monitoring at age 11 and child smoking initiation from ages 11 to 17 varied by race. Among White children, an increase of 1 point on the parent monitoring scale signaled an 11% reduction in the odds of initiating smoking by age 17. In contrast, parent monitoring was not significantly associated with smoking initiation among Black children.

DISCUSSION

The results suggest a differential influence of parent monitoring on adolescent smoking between White and Black children. Future research would benefit from close attention to parental goals and concerns and to extra-familial factors that shape smoking behavior across racially and socially disparate communities.

Fetal origins of mental health: evidence and mechanisms

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

Behavioral problems and cognitive performance at 5 years of age after very preterm birth: the EPIPAGE Study

OBJECTIVES

We compared the frequency of behavioral problems in very preterm and term children at 5 years of age. We hypothesized that behavioral problems would be associated with cognitive impairment and environmental factors and that differences between the 2 groups would be reduced but persist after adjusting for cognitive performance and environmental factors.

PATIENTS AND METHODS

The Etude Epidémiologique sur les Petits Ages Gestationnels (EPIPAGE) study was a prospective population-based cohort study that included all births occurring between 22 and 32 weeks' gestation and a control group of infants born at 39 to 40 weeks' gestation in 1997 in 9 French regions. Neonatal and obstetrics data were collected at birth. At 5 years of age, sociodemographic status and neurodevelopmental and cognitive development of the children, as well as maternal mental well-being, were assessed. The behavioral problems of 1102 very preterm and 375 term singletons without major impairments were studied by using the parent-completed Strengths and Difficulties Questionnaire.

RESULTS

Parents of very preterm children reported significantly more behavioral problems, with a twofold higher prevalence compared with term children for hyperactivity/inattention, emotional symptoms, and peer problems. Behavioral problems were associated with low cognitive performance, developmental delay, hospitalizations of the child, young maternal age, and poor maternal mental well-being. Very preterm children were still at higher risk of behavioral problems compared with term children after adjustment for cognitive performance and all others factors.

CONCLUSIONS

Behavioral problems were strongly related to cognitive impairment, but very preterm children were still at higher risk even after adjusting for cognitive performance. Early screening for behavioral problems should be encouraged for all very preterm children, and maternal well-being should also be the focus of special attention.

Externalizing behaviors in preadolescents: familial risk to externalizing behaviors, prenatal and perinatal risks, and their interactions

BACKGROUND

Accumulating evidence indicates that there is a rich and varied interplay between persons and their environments, which strongly suggests that this involves gene-environment correlations and interactions. We investigated whether familial risk (FR) to externalizing behaviors and prenatal and perinatal risk factors, separately or in interaction with each other, predicted externalizing behaviors.

METHODS

The subjects were 10- to 12-year-old preadolescents who were taking part in TRAILS, a large prospective population-based cohort study (N = 2,230). Regression analyses were used to determine the relative contribution of FR and prenatal and perinatal risks to parent and teacher ratings of inattention, hyperactivity/impulsivity aggression, and delinquency.

RESULTS

Regression models explained between 6 and 11% of the variance of externalizing behaviors. We found main effects of FR (vs. no FR), macrosomia (birth weight > 4,500 g), maternal prenatal smoking (MPS), pregnancy and delivery complications (PDCs), and gender that were rather consistent across rater and outcome measures. For some outcome measures, the effect of MPS and PDCs depended on the presence of FR. These included both positive and negative interaction effects. Correlations between FR and prenatal and perinatal risks were significant but rather low.

CONCLUSIONS

Both main effects and interaction effects of FR and prenatal and perinatal risks contributed to externalizing behaviors in preadolescents, but all effects were of small size. Further research including use of candidate gene polymorphisms is necessary to identify the underlying neurobiological mechanisms of these main and interaction effects.

ADHD correlates, comorbidity, and impairment in community and treated samples of children and adolescents

Patterns of correlates, comorbidity and impairment associated with attention-deficit hyperactivity disorder (ADHD) in children and youth were examined in representative samples from the community and from treatment facilities serving medically indigent youth in Puerto Rico. Information from caretakers and youths was obtained using the Diagnostic Interview Schedule for Children, (version IV), measures of global impairment, and a battery of potential correlates. In the community (N = 1,896) and the treated samples (N = 763), 7.5 and 26.2% of the children, respectively, met criteria for DSM-IV ADHD in the previous year. Although the prevalence rates and degree of impairment differed, the general patterns of correlates, comorbidity and impairment were similar in both populations. The exceptions were associated with conduct disorder, anxiety, impairment in the ADHD comorbid group, and age factors that appeared to be related to selection into treatment.

No ecological effect modification of the association between negative life experiences and later psychopathology in adolescence: A longitudinal community study in adolescents

BACKGROUND

The aim of the study was to examine the potential contribution of exposure to bullying and adverse life events to the development of psychopathology in adolescents, and possible effect modification by neighbourhood social capital.

METHODS

Two waves of routine, longitudinal, standard health examinations at local community paediatric health services, pertaining to 749 adolescents living in Maastricht (The Netherlands) who were attending second grade of secondary school (age 13/14 years) and approximately 2 years later going to the fourth grade (age 15/16 years), were analysed. A self-report questionnaire was used, including measures of psychopathology and two measures of negative life experiences, exposure to bullying and adverse life events, that were available for both age groups and subjected to (multilevel) regression analysis.

RESULTS

Exposure to bullying in the past school-year as well as the experience of adverse life events over a 12 month period, at the age of 13/14 years, predicted an increase in psychopathology at follow-up. Exposure to bullying was associated with the development of hyperactivity and emotional problems, while the experience of adverse life events predicted the development of conduct problems. Family-related adverse events had greatest effect sizes. Effects of bullying and adverse life events were not moderated by neighbourhood social capital.

CONCLUSION

Negative life experiences impact on liability to psychopathology in adolescents independent of the wider social environment.

Prenatal smoking exposure, low birth weight, and disruptive behavior disorders

BACKGROUND

Prenatal problems are among theorized etiologies for child disruptive behavior problems. A key question concerns whether etiological contributors are shared across the broad range of disruptive psychopathology or are partially or largely distinct.

METHOD

We examined prenatal smoking exposure and low birth weight as risk factors for attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD) in a population-based longitudinal design from ages 6 to 17 years. Multiple informants were used, with emphasis on parent and teacher report for ADHD, parent- and self-report interview for ODD, and self-report interview for CD, in keeping with evidence about the most valid sources of information for these respective syndromes.

RESULTS

The association of prenatal smoking exposure with ADHD was highly confounded by family variables. In contrast, low birth weight independently predicted ADHD, even with family variables statistically controlled. The opposite pattern appeared for ODD and CD. Prenatal smoking exposure but not low birth weight predicted ODD independent of potential confounding variables. Prenatal smoking exposure also predicted CD. The effect on CD was via its effect on ODD.

CONCLUSION

Prenatal smoking exposure may contribute to ODD and via that route to later CD, but does not have a specific association with ADHD in this sample. Findings have implications for distinct etiological contributors to these often comorbid aspects of the disruptive behavior domain.

Sex Differences in the Pathway from Low Birth Weight to Inattention/hyperactivity

Inattention/hyperactivity is a childhood outcome of low birth weight. However, the mechanisms by which low birth weight leads to inattention/hyperactivity are unclear. This study examined arousal, activation, motor speed, and motor coordination as possible mechanisms, attending to sex differences. 823 children (400 males) from Detroit and surrounding suburbs were assessed with the Child Behavior Checklist and the Teacher Report Form and completed experimental tasks to assess vigilance and activation (Continuous Performance Test signal detection parameters) and motor output speed and control (Grooved Pegboard) at 6 years of age. The relationship between birth weight and inattention/hyperactivity was slightly, but not significantly, stronger for boys than for girls. Arousal, motor speed, and motor coordination significantly partially mediated the relationship between birth weight and inattention/hyperactivity for boys and girls. Moderated mediation was found for the pathway between motor coordination and inattention/hyperactivity such that this relationship was stronger for boys than for girls. Sex differences in the associated features of attention symptoms may reflect partially distinct etiological pathways.

Small body size at birth and behavioural symptoms of ADHD in children aged five to six years

BACKGROUND

Behavioural disorders with a neurodevelopmental background, such as attention deficit hyperactivity disorder (ADHD), have been associated with a non-optimal foetal environment, reflected in small body size at birth. However, the evidence stems from highly selected groups with birth outcomes biased towards the extreme low end of the distribution in birth weight. Whether a similar association exists among the normal range of term birth is unclear.

METHODS

The ADHD Rating Scale was filled in by the biological mothers and fathers of children aged five to six years who were born healthy at term. Information on weight (kg), height (cm), head circumference (cm), and gestational age at birth were obtained from hospital records, and the ponderal index (kg/m3), a commonly used measure of thinness, and head circumference-to-length ratio were calculated.

RESULTS

Behavioural symptoms of ADHD were predicted by a lower ponderal index, a smaller head circumference, and a smaller head circumference-to-length ratio (beta's: -.12 to -.14, p's < .05). Adjustments for length of gestation, mother's age, tobacco and alcohol use during pregnancy, pre-pregnancy body mass index (BMI), or parity, the monthly gross income of the family, child's BMI at the age of five to six years or gender did not change the associations.

CONCLUSION

These results suggest that physiological adaptation in utero, indicated by small body size at birth, within term gestational range may increase the susceptibility to behavioural symptoms of ADHD.

Reports of birthweight by adolescents and their mothers: comparing accuracy and identifying correlates

Birthweight is associated with health outcomes throughout the lifespan. Official birthweight records are not always available, and researchers must rely on self-reports for birthweight information. This study evaluates the accuracy of adolescent self-reports of birthweight, using medical records as a standard, and compares it with maternal reports. It also examines potential correlates of accuracy. Respondents are 17-year-old adolescents and their mothers, who participated in a follow-up study of randomly selected samples from newborn discharge lists (1983-85) of two major hospitals in south-east Michigan. Nearly one-quarter of the adolescents stated that they did not know their own birthweight, with males twice as likely as females to respond 'don't know'. In addition, self-reports of birthweight among the remaining adolescents were inaccurate, and accuracy was inversely related to birthweight. While maternal reports of offspring's birthweight are highly accurate across diverse subgroups of the population, adolescent self-reports of birthweight are unlikely to be useful in medical research.

Gestational age, birth weight, and the risk of hyperkinetic disorder

AIMS

To study the association between gestational age and birth weight and the risk of clinically verified hyperkinetic disorder.

METHODS

Nested case-control study of 834 cases and 20 100 controls with incidence density sampling.

RESULTS

Compared with children born at term, children born with gestational ages of 34-36 completed weeks had a 70% increased risk of hyperkinetic disorder (rate ratio (RR) 1.7, 95% confidence interval (CI) 1.2 to 2.5). Children with gestational ages below 34 completed weeks had an almost threefold increased risk (RR 2.7, 95% CI 1.8 to 4.1). Children born at term with birth weights of 1500-2499 g had a 90% increased risk of hyperkinetic disorder (RR 1.9, 95% CI 1.2 to 2.9), and children with birth weights of 2500-2999 g had a 50% increased risk (RR 1.5, 95% CI 1.2 to 1.8) compared with children born at term with birth weights above 2999 g. The results were adjusted for socioeconomic status of the parents, family history of psychiatric disorders, conduct disorders, comorbidity, and maternal smoking during pregnancy. Results related to birth weight were unchanged after adjusting for differences in gestational age.

CONCLUSIONS

Children born preterm, also close to term, and children born at term with low birth weights (1500-2499 g) have an increased risk of clinically verified hyperkinetic disorder. These findings have important public health perspectives because the majority of preterm babies are born close to term.

Behavioral outcome at 3 years of age in very preterm infants: the EPIPAGE study

OBJECTIVES

Our goal was to compare the prevalence of behavioral problems between very preterm children and term children at 3 years of age and examine the factors associated with behavioral problems in very preterm children.

METHODS

We conducted a prospective population-based cohort study: the EPIPAGE (Etude Epidémiologique sur les Petits Ages Gestationnels) study. All infants born between 22 and 32 weeks of gestation in 9 regions of France in 1997 were included and compared with a control group of infants born at term. Sociodemographic status, obstetric, and neonatal data were collected at birth and in the neonatal units. At 3 years of age, the behavioral problems of 1228 very preterm singleton children without major neurodisabilities, and 447 term children were studied using the Strengths and Difficulties Questionnaire completed by the parents.

RESULTS

Very preterm children were more likely than controls to have behavioral difficulties. Among very preterm children, several medical conditions were associated with a high total difficulty score: major neonatal cerebral lesions diagnosed by cranial ultrasonographic studies, hospitalization within the last year, poor health, and psychomotor delay. A high birth order and sociodemographic factors such as young maternal age and low educational level of the mother were also identified as risk factors for behavioral difficulties. The differences between very preterm children and controls remained significant after adjustment for sociodemographic characteristics, neonatal complications, and neurodevelopmental status, for a high total difficulties score, hyperactivity, conduct problems, and for peer problems. For emotional problems, the difference was at the limit of significance.

CONCLUSIONS

Very preterm children have a higher risk of behavioral problems at 3 years of age compared with term-born children. Health and neurodevelopmental status of the child were significantly associated with behavioral difficulties.

Outcomes in adulthood for children with foetal growth retardation. A linkage study from the Nord-Trøndelag Health Study (HUNT) and the Medical Birth Registry of Norway

OBJECTIVE

The aims were to examine the long-term functional outcome and risk of mood disorders in adulthood in individuals with foetal growth retardation.

METHOD

In a prospective cohort study of 7806 individuals aged 20-30 years, using linked data from the Health Survey of Nord-Trøndelag (HUNT-2) and the Medical Birth Registry of Norway, we studied the long-term effects of being born with a birth weight below the 10th percentile for gestational age (SGA).

RESULTS

SGA individuals had lower educational level (OR: 1.33), lower socioeconomic functioning level (OR: 1.77) and more frequent reported mood disorder in adulthood (OR: 1.26). Analyses of a substratum of infants born at term showed almost identical results.

CONCLUSION

Foetal growth retardation measured as SGA shows a moderate risk for lower education and socioeconomic level and for anxiety and/or depression in young adulthood. Issues concerning interventions for children at risk should be considered.

ADHD: strategies to unravel its genetic architecture

Attention deficit/hyperactivity disorder (ADHD) is a common and impairing neuropsychiatric disorder with onset at preschool age and strong persistence over time. Its validity as a psychiatric disorder has been established according to Robins and Guze criteria. Genetic factors predominate in the etiology of ADHD. This paper summarizes the current status of genetic research into ADHD, and describes eight factors that complicate research into genetically complex disorders as ADHD. These factors are that multiple genes of small main effects are involved rather than main genes, the relevant phenotype is unknown, presence of clinical heterogeneity, presence of genetic heterogeneity, gene-environment correlation, gene-environment interaction, importance of endophenotypes, and importance of developmental factors. The further unraveling of the genetic architecture of ADHD will depend to a large extent on how well these complicating factors are handled or even used.