Children exposed to cumulative environmental risk factors in early life are more likely to present to health services for treatment for mental disorder in later childhood. We examined associations between 16 environmental risk factors occurring in early life (i.e., between the prenatal period to <6 years of age) and later diagnoses of mental disorder recorded in health service data (from age 6 to 13 years), among 71 932 children. Each environmental risk factor was examined individually, and an individual score representing cumulative exposure to multiple risk factors was also examined (i.e., a summed environmental risk score). As a child’s environmental risk score increased, so did the likelihood that they would be diagnosed with a mental disorder between age 6 to 13 years. Thirteen of the 16 environmental factors measured were positively associated with at least one category of mental disorder (including prenatal factors, neighbourhood characteristics and more proximal experiences of trauma or neglect). These findings suggest that no single environmental factor is a necessary or sufficient cause of mental disorder; multifactorial and transdiagnostic approaches are needed to understand the impact of the environment on the development of mental disorders across the life course. In many instances, environmental risk factors are preventable or capable of mitigation by appropriate public policy settings.

Children exposed to domestic violence and abuse before the age of five years are more likely to exhibit vulnerability across a broad range of developmental domains at school entry than non-exposed children. The extent of vulnerability does not appear to differ substantially between children who were the victim or witness of domestic violence, or between boys and girls. These findings are based on analyses conducted for 82,501 children drawn from the NSW Child Development Study, with findings suggesting that early contact with police may present an opportunity to identify young children who experience domestic violence and abuse and refer them for appropriate interventions. This work extends prior research in this area which often relies on mother-reported involvement in domestic violence and abuse as a proxy indicator of child exposure; studies using direct measures of child exposure to domestic violence and abuse are scarce, especially among representative population-based samples. The use of police contact records in this study therefore provides a means to more reliably identify children who had been exposed to domestic violence and abuse. The finding that witnesses of domestic violence and abuse had comparable developmental vulnerabilities to victims highlights the importance of extending support services to all young children indirectly involved in domestic violence and abuse.

Thoughts of self-harm and related behaviours in childhood (<14 years) are relatively rare, they appear to be related to intergenerational risk factors including parental mental disorders and parental offending history. While little is known about risk factors for self-harm in the age group studied here, analysis of records for 74,479 children found that 0.2% had experienced self-harm and related behaviours between the age of 3-14 years. Unlike in adolescent samples, community risk factors such as socioeconomic deprivation, remote or regional location, and neighbourhood crime rates were not associated with self-harm thoughts of behaviours in childhood. This research suggests that there may be risk factors that are passed between generations that increase the risk of childhood self-harm.

The proportion of children (aged ~5-6 years) at risk of later childhood mental disorders is generally higher in regional and socioeconomically disadvantaged areas than metropolitan areas of New South Wales (NSW). This was evident in local government area-based mapping of the geographical distribution of early childhood risk for mental disorders across the state. We specifically mapped the percentage of children in each region who were identified with distinct classes of risk identified through patterns of early developmental vulnerabilities on the Australian Early Development Census, in a population sample of 82,891 children from the NSW Child Development Study. The identification of geographical areas with a higher proportion of children who are at risk of developing mental disorders has the potential to inform the provision of place-sensitive early intervention services. While spatial trends show a high proportion (≥10%) of the children at risk for mental disorders at age ~5-6 years were predominately located in regional areas, some metropolitan areas of Sydney showed similar high proportions of risk, and conversely some regional and remote areas showed the lowest levels of risk.  These findings suggest the capacity of policymakers to prioritise place-sensitive delivery of early intervention services for children at risk of mental disorders, through information available on an existing national triennial census of children on school entry.

This study establishes three distinct childhood profiles of risk for severe mental illness in adulthood, among 22,137 children who completed the Middle Childhood Survey (MCS) when they were aged 11-12 years. The study was based on the theory that risk for schizophrenia in the general population is reflected in patterns of individual characteristics (e.g., personality and thinking style, affect, and social behaviour) collectively referred to as ‘schizotypy’. However, certain combinations of these characteristics may also indicate risk for other types of adult mental disorders. The findings suggest that around 6% of the child population are at high risk for developing schizophrenia or a related psychotic disorder (showing a profile that we referred to as “True Schizotypy”), while another 20% of the population appear to show an attenuated version of the True Schizotypy profile; a different 20% of the child population showed a distinct schizotypy profile that may indicate risk for later affective (mood) or personality disorders. These three profiles of schizotypy emerged in individual patterns of functioning across 6 broad domains, spanning ‘Unusual (perceptual) experiences’, ‘Cognitive Disorganisation’, ‘Impulsive non-conformity’, ‘Introversion’, ‘Dysphoria’, ‘Self-Other Disturbance’. Prior exposure to perinatal and familial adversities including childhood maltreatment, as well as poor early childhood development and academic functioning, was variously associated with each of the schizotypy profiles. There was also a higher proportion of childhood mental disorders already diagnosed among children showing the True Schizotypy profile, relative to the other profiles. The predictive utility of these childhood risk profiles will be determined in follow up studies of these children as they reach adolescence and early adulthood.

Up to a quarter of children at risk of multiple adverse outcomes can be detected at birth. Using data for 72,059 Australian children and their parents, we were able to determine specific combinations of perinatal and familial risk exposures, known at the time of birth, that could accurately predict a range of adverse childhood outcomes up to age 13 years. The presence of five or more risk exposures characterised 12-25% of children with between one and four or more adverse outcomes; children who experienced multiple adverse outcomes were able to be predicted with high certainty from information known at birth. Individual outcomes such as sustained educational underachievement in middle childhood, substantiated childhood maltreatment, and coming to the attention of police were able to be predicted with excellent levels of accuracy from specific sets of risk indicators known at birth. Other individual outcomes such as mental disorder diagnoses and early childhood developmental vulnerability were less accurately predicted by information known at birth. Childbirth presents an optimal time for identifying high-risk families to commence intervention that could avert various childhood health and social adversities. However, cautious application of perinatal health screening for early intervention is warranted. 


Three-quarters of New South Wales primary school principals/leaders reported delivering mental health and wellbeing programs to students, but more than one third of the programs being delivered had not yet been evaluated to determine their effectiveness. As part of the NSW Child Development Study, this paper reports the results of an online survey of 597 NSW primary school principals conducted late in 2015. The study compiled information about the delivery of school-based programs in four health-promoting domains — creating a positive school community; teaching social and emotional skills; engaging the parent community; and supporting students experiencing mental health difficulties — and considered this information in relation to published ratings of the effectiveness of these programs. There was variability in the use of evidence-based programs across the four health-promotion domains, and limitations in the amount of evidence of effectiveness available to support the programs. All Australian schools are now required to deliver a mental health and wellbeing curriculum to students. Our findings indicate a need to provide educators with improved support to identify, implement, and evaluate effective evidenced-based programs that promote student mental health.

Children exposed to multiple birth and familial risk factors during the perinatal period are significantly more likely to experience adverse outcomes in childhood. These findings were evident in retrospective analyses of linked administrative records (between 2001-2016) for 72,059 children and their parents from the NSW Child Development Study (NSW-CDS). While many early-life risk factors for adverse outcomes in childhood have been identified, these risk factors rarely occur in isolation. The goal of this study was therefore to explore the impact of familial clustering of risk factors on subsequent adverse outcomes for the offspring in early and middle childhood. Four groups of children exposed to distinct combinations of risk factors (known at the time of birth) were identified – No risk, multipara+perinatal risk, young mother+perinatal risk, and pervasive familial risk. Children belonging to any of the three risk groups, particularly the pervasive familial risk group, were significantly more likely to experience developmental vulnerability, academic difficulties, mental disorders, child maltreatment, and contact with police as a victim or person of interest before the age of 13 years. These findings may help to refine the targeting of family-focused intervention strategies during the perinatal period.

A broad range of early childhood factors each make individual contributions to a student’s risk of suspension from primary school, including male gender, referral to child protection services, early externalising behaviours, a diagnosed emotional or behavioural problem, socioeconomic disadvantage, pregnancy and birth factors, academic underachievement, physical injury, and parental criminal offending and mental illness. This study analysed multi-agency linked data on 34,855 children from the NSW Child Development Study using multivariate logistic regression, to examine the associations between early childhood factors that were present by the end of 2nd grade (approximately 8 years of age) and suspension from primary school during the 3rd through 6th grades. The study provides information to help identify students at risk of early suspension, so that they can be supported to engage effectively with learning at school. A comprehensive multi-agency response is required, which could include school-based programs supplemented by support from health and social services agencies throughout the early childhood period, including in early childhood settings and during the initial years of school.  

A significant proportion (~65%) of children known to child protection services show profiles of socio-emotional and cognitive resilience from early to middle childhood. One group of children (54% of those known to child protection services) show a profile of stress-resistance, and a smaller group (13% of those known to child protection services) show a profile of emergent resilience. These findings emerged in latent profile analyses of a NSW cohort of 4,716 children known to child protection services by age 13 years, in which multi-dimensional profiles of resilience were evident in social, emotional and cognitive functioning when assessed at age 5-6 years (Time 1) and age 10-11 years (Time 2). Factors associated with both of the resilience profiles included being female, and personality characteristics of openness and extraversion; other factors associated with stress-resistance, specifically, included higher socioeconomic status, non-Indigenous background, higher perceived support at home and at school, and not having a parent with a history of criminal offending. These findings suggest that a complex interplay between individual, family, and community characteristics confer resilience at critical periods in the life course. Resilience processes have been less studied in this developmental period between early to middle childhood, relative to later periods of adolescence or adulthood.
Children who are hospitalised for an infectious condition in early childhood (birth to 4 years) are more likely to be diagnosed with a mental disorder between the ages of 5 and 13 years. This was revealed in a study of 71,841 children in which the effects of both prenatal and early childhood exposure to infection were examined in relation to later diagnosis of mental disorder in childhood. A total of 2,027 children were exposed to maternal infection during the pregnancy period (prenatal exposure) and 16,356 children were exposed to infection in early childhood. While the incidence of any mental health condition, as well as specific internalising, externalising and developmental disorders, were all crudely associated with both prenatal and early childhood infection, only the latter remained significantly associated with mental disorder diagnoses in childhood when other factors were considered (e.g., child’s sex, socioeconomic status, maternal age at child’s birth, maternal smoking during pregnancy). Exposure to infectious diseases during early childhood, but not prenatal infection exposure, appears to be associated with earlier diagnosis of mental disorders in childhood.

Children who have been in contact with child protection services before age 10 years are more likely to self-report mental health difficulties than their peers with no child protection contact, regardless of the type of child protection contact (i.e., whether the report results in the child being placed in out-of-home care, the report is substantiated but the child remains in home, the report is unsubstantiated, or the report is determined not to meet the threshold for risk-of-significant harm). This finding was revealed in a study of 26,290 children from the NSW-CDS who completed the online self-report Middle Childhood Survey when they were aged 11 years; the children answered questions about difficulties with emotional symptoms, peer relationships, conduct problems, hyperactivity-inattention, prosocial behaviours, and psychotic-like experiences. Relative to their peers, children with child protection were more likely to report difficulties in all these areas of mental health, with 48% of children in out-of-home care and 46% of children with substantiated reports reporting clinical levels of difficulties in at least one mental health domain. These findings highlight the need for mental health supports for all children in contact with child protection services.

Children with emotional or behavioral problems identified at school entry have twice the rate of subsequent police contact of children without such problems. These elevated rates of police contact were evident for all types of contact with police – as a person of interest, survivor of crime, or witness. Using data from the NSW Child Development Study, a cohort of almost 80,000 children were followed from their first year of full-time schooling to 13 years of age, with available linked police contact data and teacher-assessments of developmental vulnerabilities from the Australian Early Development Census. Individuals with mental health problems are well known to have higher rates of contact with the criminal justice system later in life, but this study confirms that the association emerges in early life. Early police contact, for any reason, may represent an opportunity to identify and intervene with vulnerable young people and their families to prevent later adversity. School entry also presents an opportunity to identify children who have emotional, behavioural and other developmental vulnerabilities that put them at increased risk of early justice system contact.

Young people with multiple types of contact with the police by age 13 years (e.g., as both a person of interest and a victim and/or witness) are more likely to be boys, live in a socioeconomically disadvantaged area, be born to younger mothers or be of Aboriginal and/or Torres Strait Islander background relative to young people who had no contact with the police. The most common first contact type was as a victim/witness but those children with a first contact as a person of interest were most likely to have at least one further contact. This evidence comes from linked NSW Police Force data for 91,631 young people included in Wave 2 of the NSW Child Development Study, in which one in ten young people (10.6%) have had contact with the police for a criminal incident by the age of 13 years as a person of interest, victim or a witness; among these children, 14.4% had been in contact with police as both a person of interest and a victim and/or witness. While there is a known overlap between perpetrators and victims of crime in adulthood, this research provides new evidence about the extent of this overlap early in life among children and young adolescents, and their sociodemographic characteristics. This research can inform targeted early identification and intervention programs that consider a wide range of risk factors to reduce the risk of future adversity, including early and multiple contact with police. 

Children reported to child protection services before the age of 5 years show higher rates of developmental vulnerability, academic under-achievement, self-reported psychopathology, and contact with the police (relative to children not subjected to such reports), in line with a greater level of child protection response. This report was commissioned by the NSW Department of Communities and Justice (DCJ) to improve their policies and practice around identifying and assessing child need, to ensure safety, wellbeing, and positive life outcomes for children in out-of-home care (OOHC). The brief received from DCJ requested information about a diverse array of developmental outcomes among children with substantiated ‘Risk of Significant Harm’ (ROSH) reports or those who had been placed in OOHC. Each developmental outcome in childhood was thus examined with respect to (a) the highest level of child protection response (non-ROSH, non-substantiated ROSH, substantiated ROSH, or OOHC placement); (b) the number of ROSH reports; (c) single or multiple (substantiated) maltreatment types (physical abuse, emotional abuse, sexual abuse, or neglect); (d) the type of substantiated maltreatment (physical abuse, emotional abuse, sexual abuse, or neglect) among those exposed to a single type of maltreatment only; (e) exposure to various other risk factors spanning individual, familial, and contextual factors. There were generally higher rates of adverse developmental outcomes among those with multiple child protection reports and exposed to more than one type of maltreatment. The adverse developmental outcomes of children with child protection reports were augmented by the child’s sex (males overrepresented in poor performing groups), socioeconomic disadvantage, Indigenous status, young maternal age at birth of child, maternal smoking during pregnancy, pre-term birth, parental mental illness, and parental criminal offending. These risk factors are known to be associated with child protection involvement as well as with many adverse health and social outcomes throughout childhood, adolescence, and adulthood. 

Having a mother with a mental disorder, or a mother or father with a prior criminal conviction are independently associated with earlier contact with the child protection system and placement in out-of-home care (OOHC). This paper presents findings from 71,661 children and their parents drawn from the NSW-CDS. This study examined the impact of maternal and paternal criminal convictions and mental disorders on the time to offspring’s first contact with the child protection system and/or OOHC placement. Around 20% of mothers and 50% of fathers had a criminal conviction prior to their child’s first contact with the child protection system. By contrast, 23% of mothers and 14.3% of fathers were previously diagnosed with a mental disorder. Having a mother or father with a prior criminal conviction, or a mother with a mental disorder, were each independently associated with earlier first contact with the child protection system and placement in OOHC. The largest effects were for paternal criminal conviction and time to first child protection contact (almost a two-and-a-half times greater incidence), and maternal criminal conviction and time to first OOHC placement (two-and-a-have times greater incidence). These findings demonstrate the potential benefits of coordinated government responses to identify vulnerable children and families who might benefit from inter-agency support services.


Child protection contacts prior to age 6 years were more prevalent among children with special healthcare needs (SHCN) compared to their peers without SHCN. This paper presents findings from 65,349 children using administrative data from the New South Wales Child Development Study. We examined the characteristics of contact with child protection services before age 6 years, among children identified with ‘special needs’ or other impairments of concern on the 2009 Australian Early Development Census, in their first year of formal schooling. While children with disabilities are known to have high rates of contact with child protection, little is known about the broader group of children with SHCN. In this study around 30% of children with broad SHCN had contact with child protection services prior to the age 6 years, compared to 16% of children without SHCN. Children with SHCN had higher odds of a history of exposure to neglect and physical abuse, and higher odds of being placed in out-of-home care, compared to their typically developing peers. Understanding the relationship between child protection contact among children with SHCN, will inform the development of appropriate policy initiatives to fulfil Australia’s obligations under the United Nations Convention on the Rights of the Child.

Children of parents with a history of criminal offending are more likely to demonstrate antisocial behaviour. However, few studies have examined whether this relationship is gender-specific. This study examined antisocial behaviour in children at three developmental stages: in early childhood, using the Australian Early Development Census administered at age ~5 years; in middle childhood, using the Middle Childhood Survey administered at age ~11 years; and in early adolescence, at ages 13 to 16 years using police contact data. Participants comprised three population samples from Wave 2 of the NSW-CDS, with 66 135, 21 630 and 71 661 children included in the early childhood, middle childhood and early adolescent groups, respectively. Using inter-agency linked data we found the patterns of intergenerational transmission varies for girls and boys, with stronger associations between parental offending and antisocial outcomes in daughters than sons. The largest effects were demonstrated in early adolescence, where sons and daughters of offending parents were approximately 3 and 4 times more likely to have been in contact with the police, respectively. This research indicates that daughters of offending parents are at particularly high risk of contact with police, and suggests that both boys and girls with offending parents would benefit from targeted intervention programs. 

Patterns of social-emotional and cognitive functioning assessed at age 5-6 years and age 10-11 years in a large population-based sample demonstrate that the majority of children (78%) who were developing as expected in early childhood continued to develop as expected in middle childhood. However, a substantial proportion of children who were developmentally vulnerable for social-emotional (42%) and cognitive (41%) functioning in early childhood remained vulnerable in middle childhood, and a smaller group of children (22%) showed decline in social-emotional and cognitive development over time. These findings were generated in a study of 19,087 children and their parents in the NSW-CDS who provided data to examine patterns of socio-emotional and cognitive development during early and middle childhood, and the influence of familial risk factors (child’s sex; socioeconomic disadvantage; child protection contact; parental mental illness and criminal offending) on transitions in these skills over time. Early socio-emotional and cognitive skills are linked to adult mental health and poor educational attainment, under-employment and criminal activity, so it is important to understand how children’s socio-emotional and cognitive vulnerabilities develop and identify factors that influence their development. Around 40% of vulnerable children in early childhood remained vulnerable in middle childhood. Male children, those been in contact with child protection services, or who had a parent with mental illness or involved in criminal offending, were more likely to be represented in the vulnerable group in middle childhood. The early detection of vulnerable children and the factors influencing this vulnerability are important steps in directing future health and social policy, and service planning.

Nearly one in six (15.6%) children have had contact with police by age 13 years – as either a victim, person of interest or witness – according to this Australian population-based study. This paper presents preliminary analyses of linked NSW Police Force data for 91,631 children from Wave 2 of the NSW-CDS. A total of 14,329 de-identified children were recorded as having any contact with the police in NSW as a victim, person of interest or witness. Data of this nature, specifically population estimates on police contacts, are crucial to begin to understand the developmental trajectories of criminal justice system involvement, and associated early-life risk factors. Interestingly, approximately half of the children with police contact as a person of interest (50.6%) or witness (46.6%), also had a separate contact as a victim. Preliminary analyses examining risk factors for police contact identified socioeconomic disadvantage, Aboriginal and Torres Strait Islander background, young maternal age at the child’s birth, and residential remoteness as increasing the risk of children coming into contact. This study provides the first epidemiological study of police contacts in a representative population-based sample of Australian children.

Children reported to child protection services are more likely than unreported children to attain below average reading and numeracy, and less likely to attain above average national standards. Data from 56,860 children and their parents in the New South Wales Child Development Study were used to examine the associations between different levels of child protection reports (children placed into out of home care, children with substantiated maltreatment who were not placed in to care, and two groups of children with unsubstantiated maltreatment reports, compared to children with no reports) and 3rd - and 5th -grade reading and numeracy attainment on the National Assessment Program-Literacy and Numeracy. We considered the role of multiple other individual, family, and neighbourhood adversities that may confound these relationships. Children with any type of child protection report experienced greater risk of poor reading and numeracy attainment. Maltreated children not placed into care demonstrated the worst reading and numeracy attainment, with some evidence of a potential beneficial effect of care placement for maltreated children. The findings endorse policies that promote collaboration, training, and information sharing between child protection and education systems, as well as other agencies, to support the academic achievement of all vulnerable children with child protection reports, and broader provision of universal and targeted interventions depending on the report level.

Children in contact with child protection services show higher rates and costs for physical and mental health hospitalisations in each of their first 13-years of life, with mental health hospitalisations for children with out-of-home-care (OOHC) placement 5-fold greater than children not known to child protection services. The analysis was based on hospital records for a cohort of 79,285 children from the NSW-CDS. Costs were estimated from birth (as available) using Round 17, National Hospital Cost Data Collection. Records of the NSW state child protection authority determined child protection contact status, and mental health hospitalisations comprised hospital separations with a primary mental disorder diagnosis recorded. The use of linked population data provides an effective means of examining health costs associated with childhood maltreatment, for which there is otherwise a limited knowledge base. Using multi-agency linked data analysis we found that mental health costs per child were always significantly higher for children with child protection contact, with critical periods for the onset and/or identification of mental disorders among children known to child protection services. Our findings should support the prioritization of mental health care for children known to child protection services, and provide the first evidence of age-related mental health costs for children placed in OOHC, at critical stages of development.

Children reported to child protection services before the age of 5-6 years are more than twice as likely to be diagnosed with a mental illness before age 13 years, than children not known to child protection services during early childhood. Among these children, those placed in out-of-home-care are at greatest risk of mental health problems, being more than 5 times more likely to be diagnosed with a mental illness by age 13 years. These findings arose from retrospective analysis of 74,462 children for whom linked administrative data was available from 2001–2016, from the NSW Child Development Study (NSW-CDS) Wave 2 data linkage. Among this population, 13,796 children (18.5%) had been the subjects of reports to child protection services before age 5-6 years, and 1,148 children (1.5%) had been placed in out-of-home care in early childhood. These findings follow considerable evidence showing that exposure to child maltreatment is a strong risk factor for adult-onset mental disorders. We provide the first detailed information about the type of mental disorders emerging in childhood following actual maltreatment, as well as children who have been notified to child protection services as being at high risk of future harm. All children who are reported to child protection services during early childhood require specific mental health support and care. 

Childhood experiences of hallucinations and delusions (psychotic-like experiences) increase risk for concurrent and future psychiatric disorders but are relatively common in the population. For most children, these experiences are benign and transitory, but strategies are needed to identify vulnerable children who may benefit from monitoring or targeted intervention. This study sought to identify patterns of childhood psychotic-like experiences in the general population, and the relationship of particular profiles of responses with other psychopathologies. Participants in the study were 27,000 Australian children from the NSW-CDS population cohort who completed the online self-report Middle Childhood Survey, including items assessing psychotic-like experiences and emotional, peer relationship, conduct, and hyperactivity-inattention psychopathology. Five classes of response patterns to psychotic-like experiences were identified, reflecting None (27.4% of children), Minor (29.7%), Moderate (11.8%), Hallucinatory (21.0%), and Strong (10.2%). The odds of multiple psychopathology were greater in the Hallucinatory and Strong groups.


This study sought to determine the minimum set of indicators available in cross-agency administrative data that could be used to accurately distinguish children placed in out-of-home-care from the wider group of children known to child protection services, and from the general population unknown to child protection services. Participants comprised a population sample of 72,079 children and their parents, including 1,239 children who had been placed in out-of-home-care, 15,367 children who had been reported to child protection services but had no record of out-of-home-care placement, and 55,473 children who had no previous contact with child protection services (up to age 13–14 years). A combination of six risk indicators was able to classify children placed in out-of-home-care with approximately 95% accuracy. These findings show that several key risk factors available in administrative records held by multiple government agencies may be used to identify vulnerable children, for whom targeted family support services may prevent future out-of-home-care placements.

This study examined the associations between chronic physical health conditions which are monitored and managed in NSW public schools under Individual Health Care Plans (namely asthma, allergies and anaphylaxis, type 1 diabetes, and epilepsy) and emotional, social, and behavioural difficulties assessed at age 5 years on the teacher-reported Australian Early Development Census, and at age 11 years using the self-report Middle Childhood Survey. Participants were 21,304 children from the NSW-CDS, of whom 7.5% had a hospital record of at least one of these conditions by early childhood (age 5 years), and 10.7% by middle childhood (age 11 years). Relative to peers who had no hospital records of these chronic health conditions, children with any of these health conditions experienced a small increase in selected emotional, behavioural, and social problems, as well as overall (total) problems at both assessment points (age 5 and age 11 years). Despite these difficulties, children identified with chronic health conditions were just as likely as their peers without such conditions to identify feeling supported or connected at home, school, in their community, and with their natural environment.

This paper examined the incidence of Emergency Department presentations among child offspring of parents with criminal offending records, in a population sample of 72,772 children and their parents drawn from the New South Wales Child Development Study. Rates of Emergency Department presentation, particularly for physical injury, were higher among children with parental history of criminal offending (and greatest for paternal criminal offending), after adjusting for the contribution of other risk factors such as parental mental illness, Aboriginal and/or Torres Strait Islander background, low socioeconomic status, maternal age at birth, and the child's sex. These findings suggest children of parents with a history of criminal offending have an increased risk of childhood presentations to the Emergency Department, including for potentially avoidable physical injury. 

This paper examined associations between early developmental vulnerabilities (at age 5 years) and (1) the highest level of child protection response (where out-of-home-care was deemed the highest response among other types of reports/responses), and (2) the timing of the first child protection report during early development. The sample included 67,027 children drawn from the New South Wales Child Development Study, of whom 10,944 were reported to child protection services up to age 5 years. The results indicated that children with substantiated maltreatment reports showed the strongest odds of vulnerability on three or more developmental domains relative to children with no child protection report (followed by children placed in out-of-home-care, then children with unsubstantiated child protection reports). Children placed in out-of-home-care showed slightly better physical, cognitive and communication competencies than those with substantiated reports that did not result in out-of-home-care placements (when each group was compared to children with no child protection reports). Children with first maltreatment reports occurring in the first 18 months of life showed the strongest likelihood of developmental vulnerabilities on three or more developmental domains relative to children with reports in later years of childhood, when each group was compared to children with no child protection reports. The findings show early reports of maltreatment may signal the need for targeted remediation of early developmental competencies to mitigate early developmental difficulties.

This paper examined associations between developmental vulnerability profiles determined at the age of 5 years, and subsequent childhood mental illness diagnosed between ages 6 and 13 years, in a population sample of 86,668 children from the New South Wales Child Development Study (NSW-CDS) cohort. Membership of putative risk classes in early childhood were delineated via latent class analysis of Australian Early Development Census subdomains, and children designated as those with established ‘special needs’ at school entry were examined as a separate group of interest. The results indicated that the crude odds of being diagnosed with any mental disorder between the ages of 6–13 years was increased approximately threefold in children showing ‘pervasive' risk or ‘misconduct' risk profiles according to their AEDC vulnerability patterns at age 5 years, relative to children showing no AEDC vulnerabilities. The odds of mental illness among children with special needs was increased approximately sevenfold, relative to children showing no AEDC vulnerabilities, before adjusting for other contributing factors (e.g., parental mental illness history, child protection records, socioeconomic status, child’s sex). These findings show that distinct patterns of early childhood developmental vulnerability are associated with subsequent onset of mental disorders, and that AEDC risk profiles have the potential to inform interventions to mitigate the risk for mental disorders in later childhood and adolescence.

This study examined the relationship between parental offending and the continuity and discontinuity of children’s conduct, attentional, and emotional difficulties from early to middle childhood while also considering the role of timing of the parental offending exposure. We specifically tested associations between mother’s and father’s history and timing of any and violent offending, and patterns of continuity or discontinuity in offspring emotional, conduct, and attentional difficulties between ages 5 and 11 years, in a population sample of 19,208 children and their parents drawn from the New South Wales Child Development Study (NSW-CDS) cohort. Maternal and paternal offending each conferred increased risk of all patterns of developmental difficulties, including those limited to age 5 only (remitting problems), to age 11 only (incident problems), and difficulties present at both ages 5 and 11 years (persisting problems), with the greatest associations observed between parental offending history and persisting conduct problems. Paternal offending that continued through early and middle childhood had the greatest association with child developmental difficulties, while the timing of maternal offending had a less prominent effect on child developmental difficulties.

This study examined the the link between parental criminal offending history and offspring behaviour in middle childhood, in a population sample of 21,956 children drawn from the NSW Child Development Study (NSW-CDS). Specifically, the prevalence of offending among mothers and fathers was examined in relation to the children’s conduct problems at age 11 years. The findings showed that parental offending history increased the likelihood of conduct problems among offspring, and that maternal violent offending was most strongly associated with conduct problems in middle childhood. The findings suggest that the intergenerational transmission of antisocial behaviour begins early, highlighting the importance of intervention for at-risk children and programs targeted at mothers as well as fathers.

This paper describes the development of a brief school-based instrument designed for use in research and in educational practice. The Survey of School Promotion of Emotional and Social Health (SSPESH) measures the extent to which a school has implemented policies and practices in four health-promoting domains: (a) creating a positive school community, (b) teaching social and emotional skills, (c) engaging the parent community, and (d) supporting students experiencing mental health difficulties. The questionnaire can be used to differentiate high, moderate, and low implementation of whole-school policies and practices that promote the emotional and social health of students. To develop the instrument, responses were gathered via an online survey of Principals in almost 600 Australian primary schools in New South Wales during 2015. The paper describes the preliminary psychometric properties of the instrument (reliability, validity), and the development of the implementation index using Latent Class Analysis methods. This brief 13-item survey can be used by researchers and evaluators for comparative and multivariate analyses. School leadership may find it useful as a brief tool to guide the identification of target areas for whole-school improvement across the four important health-promoting domains.


This report provides a description of the NSW Child Development Study cohort, and what has been measured in the cohort, following the second record linkage (Wave 2) in 2016. The child cohort is comprised of 91,635 children, defined by inclusion in the NSW Australian Early Development Census (AEDC) of 2009 at school entry (n=87,037) and/or the investigator-led Middle Childhood Survey (MCS)conducted in 2015 (n=27,792). The MCS captured 26.6% of the original 2009 AEDC cohort, and also brought 4598 new children into the cohort; 23,194 children contributed records to both the AEDC and MCS assessments. Wave 2 brings together each child’s birth, mortality, health, academic achievement, school enrolment, school suspensions and expulsions, child protection and criminal records, linked with their mothers’ perinatal records, and with both parents’ mortality, health and criminal records, where available. This report describes the linkage rates for each of these record sets, as well detailed information about each record set, and characteristics for the child and their parents. Published findings from the study to date, its strengths and limitations and future directions, are also discussed. 

This study examined the associations between quantity of prenatal smoking and frequency of maternal offending and offspring behavioural and cognitive outcomes at age 5 years, while accounting for other prenatal and family risk factors. Prenatal smoking and frequent maternal offending (comprising two or more offences) were associated with all developmental vulnerabilities examined, even after adjusting for other familial and prenatal risk factors. Population attributable fractions (PAFs) for prenatal smoking ranged from 5.3% to 15.8% and PAFs for maternal offending ranged from 3.4% to 11.8% across the offspring outcomes. These findings suggest prevention and intervention efforts during prenatal periods for vulnerable families may have benefits for both behavioural and cognitive problems in early childhood. 

This study examined connection to the natural environment in relation to well-being in childhood, in the context of other factors known to influence wellbeing such as social supports, attention, and empathic skills. We used a representative sample of 26,848 children from the NSW Child Development Study (NSW-CDS) who completed the Middle Childhood Survey (a self-report survey of mental health and well-being) that was undertaken when the children were aged approximately 11 years. The results indicated that connection to nature was positively, albeit weakly, associated with two indicators of well-being: self-satisfaction and prosocial behaviour, while other factors had stronger effects on wellbeing. For example, social supports had the strongest relationship with self-satisfaction, while empathy had the strongest relationship with prosocial behaviour. These findings suggest that developing a connection to nature can slightly improve well-being, and may augment education-based programs to improve wellbeing in childhood.

Brief self-report questionnaire measures of the Big Five personality dimensions in children are needed for use in large population studies, for which longer instruments are not suited. The Big Five traits describe individual differences in personality within the population, with the expression of each trait in an individual varying along a dimension. These Big Five traits include: Agreeableness (generous, honest, modest vs. selfish, aggressive, arrogant), Conscientiousness (dependable, achievement-driven, constrained vs. disorderly, laid-back, unambitious), Neuroticism (worried, anxious, sad, vs. emotionally stable, calm), Extraversion (warm, outgoing, cheerful vs. introverted, reserved, solitary, sombre), and Openness to experience (curious, exploratory vs. rigid, practical, traditional). This study established the psychometric properties (reliability, validity) of a brief self-report measure of the Big Five personality dimensions in children, using data from 27,415 children in the NSW Child Development Study cohort. The psychometric properties were examined using Item Response Theory methods, exploratory and confirmatory factor analyses. The findings demonstrate the suitability of the brief, 20-item short-form measure of the Big Five personality dimensions in children for administration online in large population-based studies. The questionnaire could be useful in research examining how personality traits in childhood might act as risk or protective factors for later adolescent and adult health and well-being outcomes, and thereby inform public health policy and practices that promote mental health and prevent mental illness.

 This study investigated the effects of in utero exposure to maternal infection and noninfectious diseases during pregnancy on offspring developmental vulnerabilities at age 5 years, in a population sample of 66,045 children drawn from the NSW Child Development Study (NSW-CDS) cohort. Maternal infectious diseases during pregnancy and early childhood infection conferred the largest associations with developmental vulnerabilities at age 5 years; maternal noninfectious illness during pregnancy also retained small but significant associations with developmental vulnerabilities even when adjusted for other physical and mental illness exposures and covariates known to be associated with early childhood development. Among all exposures examined, maternal mental illness first diagnosed prior to childbirth conferred the greatest odds of developmental vulnerability at age 5 years. Prenatal exposure to infectious or noninfectious diseases appear to influence early childhood physical, social, emotional and cognitive developmental vulnerabilities that may represent intermediate phenotypes for subsequent mental disorders.

 This study examined patterns of association between externalising and internalising vulnerabilities in early childhood and parental mental disorder, in a population sample of 69,116 children drawn from the NSW Child Development Study (NSW-CDS) cohort. Measures of externalising and internalising vulnerability, obtained via the Australian Early Development Census, were linked to administrative health datasets to determine parental psychiatric diagnostic status. Parental mental illness, across diagnostic categories, was associated with all child externalising and internalising domains of vulnerability. These findings have important implications for informing early identification and intervention strategies in high-risk offspring and for research into the causes of mental illness.

This study determined classes of children among the general population who may be at risk for later mental disorder on the basis of early patterns of developmental functioning, and the associations of each risk-class with exposure to childhood maltreatment, parental mental illness, parental offending, and perinatal adversities, and other demographic factors. Data from 16 subdomains of the Australian Early Development Census (AEDC) were used to determine classes of children with shared patterns of developmental vulnerabilities in a population sample of 67,353 children drawn from the New South Wales Child Development Study (NSW-CDS) cohort. Four classes were identified, reflecting putative risk states for mental disorders: (1) disrespectful and aggressive/hyperactive behaviour, labelled ‘misconduct risk’ (6.5%); (2) ‘pervasive risk’ (4.0%); (3) ‘mild generalised risk’ (11.6%); and (4) ‘no risk’ (77.9%). The odds of membership in putative risk groups (relative to the no risk group) were greater among children from backgrounds of child maltreatment, parental history of mental illness, parental history of criminal offending, socioeconomic disadvantage, and perinatal adversities. 

This study examined the structure of the Best Start Kindergarten Assessment (Best Start) of literacy and numeracy, in a general population sample of 37,734 children drawn from the NSW Child Development Study (NSW-CDS) cohort. Analyses conducted on the 11 Best Start scales supported a two-factor structure underpinning literacy and numeracy attainment. This two-factor measure of attainment at school entry is comparable in structure to standardised measures of literacy and numeracy administered in later school years, and may thus facilitate research examining pathways of academic performance over time.

 The study focused on the effects of early life maltreatment on early childhood developmental outcomes, including examination of the effects of multiple maltreatment types and the timing of maltreatment in a large population sample. We specifically examined associations between the type, and timing of childhood maltreatment and early developmental vulnerabilities in a population sample of 68,459 children (34,562 males) drawn from the New South Wales Child Development Study (NSW-CDS) cohort, using linked administrative data for children and their parents (collected from 2001-2009). The mean age of the child sample was 5.62 years (SD=0.37), and 2,135 children had already been exposed to (substantiated) maltreatment according to child protection records. Exposure to any type of childhood maltreatment was associated with pervasive developmental vulnerability at age 5 years. Children exposed to two or more maltreatment types, and with first maltreatment reported after 3 years of age, showed greater likelihood of vulnerability on multiple developmental domains relative to non-maltreated children. These patterns of association were found in the context of other important risk factors for early childhood developmental vulnerabilities that have been implicated in previous studies (e.g., male sex, maternal smoking during pregnancy).


This study examined the impact of parental criminal offending, both paternal and maternal, on offspring aggression at age 5 years. Parental mental illness, child’s sex, and socioeconomic disadvantage were also accounted for in the analyses. Offspring aggression was assessed using the Aggressive Behaviour subdomain of the Australian Early Development Census (AEDC), a teacher-reported cross-sectional survey on child development. Parental criminal offending was obtained from NSW Bureau of Crime Statistics data and parental mental health was obtained from NSW Admitted Patients and Mental Health Ambulatory data. Parental history of violent and frequent offending increased the risk of high levels of aggression in offspring during early childhood, highlighting the need for intervention with affected families during this key developmental period.

This report examined the impact of parental criminal offending on developmental outcomes at age 5 years. Data from the Australian Early Development Census, a teacher-reported assessment of childhood development across five key domains, was linked with maternal and paternal offending histories obtained from official records. Children whose parents had a history of criminal offending were at significantly greater risk of developmental vulnerability on each of the five domains. The risk of vulnerability increased further when both parents offended, when mothers rather than fathers offended, and when the offending was of a violent nature. For all types of offending, children were more likely to be vulnerable on multiple domains than on a single domain. These findings indicate a widespread impact of parental offending on early childhood development and highlight the need to support affected families in order to improve outcomes.


This report provides a description of the characteristics of children who make up the NSW Child Development Study cohort. This group comprises 87,000 children who commenced their formal school education in 2009, and for whom class teachers completed the Australian Early Development Census (AEDC). Rates for the successful linkage of the AEDC records with other administrative data for the children and their parents are provided within this publication, and information about the demographic characteristics (e.g., sex, geographic and socioeconomic distributions), as well as the representativeness of this group to a comparable national population. The strengths and limitations of the study are also discussed.

This report provides a description of responses to the Middle Childhood Survey (MCS), a computerised self-report assessment of children’s mental health and well-being completed by 27 808 children aged 11-12 years in New South Wales (NSW) schools in 2015. The MCS sample includes 85.9% of students enrolled at the 829 schools who participated in the MCS (35% of eligible schools in NSW), and these participating schools and children are representative of the NSW population. The MCS measured Social Integration, Prosocial Behaviour, Peer Relationship Problems, Supportive Relationships (at Home, School and in the Community), Empathy, Emotional Symptoms, Conduct Problems, Aggression, Attention, Inhibitory Control, Hyperactivity-Inattention, Total Difficulties (internalising and externalising psychopathology), Perceptual Sensitivity, Psychotic-Like Experiences, Personality, Self-esteem, Daytime Sleepiness and Connection to Nature. This report presents response distributions on each of these indices, indicating the range of competencies and vulnerabilities in the population. 

This study examined the relationship between early childhood infections requiring hospitalisation and developmental vulnerability at age 5 years, as assessed using the Australian Early Development Census (AEDC). The AEDC provides an index of each child’s level of function on five domains, including Physical Health and Wellbeing, Social Competence, Emotional Maturity, Language and Cognitive Skills, Communication Skills and General Knowledge. Hospital admissions for infections were associated with vulnerability on all five developmental domains. This suggests that severe infections during early childhood may pose a risk to development by school-age.

This study examined the associations between early childhood maltreatment (age 0-5 years) and childhood social and emotional functioning at approximately age 5 years. This was achieved by linking Family and Community Services Data, parental Mental Health Ambulatory and Admitted Patients Data and Australian Early Development Census Data. Medium-sized associations were found between maltreatment and poor social competency, aggressive behaviour, and hyperactive/inattentive behaviour, and small associations were found between maltreatment and poor prosocial/helping and anxious/fearful behaviour. These associations overshadowed the impact of having a parent with schizophrenia spectrum disorders. The results suggest childhood maltreatment may adversely impact on early childhood social and emotional functioning to a greater extent than parental schizophrenia and related disorders. 


This scientific review provides a summary of the available evidence relating to risk factors for the development of schizophrenia spectrum disorders (e.g., schizophrenia, schizoaffective disorder), and affective psychoses (e.g., bipolar disorder). A total of 127 papers were reviewed for the purpose of evaluating the evidence for various risk factors as potentially conferring risk for psychoses, and to highlight gaps in the evidence base. Factors which conferred the greatest risk, or were observed most consistently to confer risk to both affective and non-affective (schizophrenia spectrum) psychoses, included: obstetric complications, maternal illness during pregnancy (especially infections), other maternal physical factors, negative family emotional environment, psychopathology and psychotic symptoms, and cognitive and motor dysfunctions. 


This study describes a method that we have tested to determine the performance of four different methods for assigning a single diagnosis (for a psychotic disorder) from health records in which multiple diagnoses can be recorded for a single individual over time. Administrative health records are valuable research tools but the methods to extract accurate mental health diagnoses can be challenging because of the number of admissions for any given individual. The methods tested in this report include testing the validity of using: ‘any’ diagnosis, ‘most recent’ diagnosis, ‘most frequent’ (modal) diagnosis or ‘hierarchy’ (where a diagnostic hierarchy was applied). Overall agreement between administrative and reference diagnoses was modest with different methods producing results of varying accuracy. This illustrates that the choice of methods used to summarise health records can impact the accuracy of diagnosis and hence is an important consideration for study methods. 

This scientific report examined the association between early life risk factors and academic achievement at Kindergarten (approx. age 5) and in Grade 3 (approx. age 8). This was achieved by linking the NSW Midwives data collection with the Best Start Kindergarten Assessment. Increasing maternal age and lack of maternal prenatal smoking were associated with improved academic performance. The results suggest that programs that target children with less developed academic skills during the first year of school may improve subsequent results.