Felicity Harris

Common or distinct pathways to psychosis? A systematic review of evidence from prospective studies for developmental risk factors and antecedents of the schizophrenia spectrum disorders and affective psychoses

BackgroundIdentifying the unique and shared premorbid indicators of risk for the schizophrenia spectrum disorders (SSD) and affective psychoses (AP) may refine aetiological hypotheses and inform the delivery of universal versus targeted preventive interventions. This systematic review synthesises the available evidence concerning developmental risk factors and antecedents of SSD and AP to identify those with the most robust support, and to highlight remaining evidence gaps.MethodsA systematic search of prospective birth, population, high-risk, and case-control cohorts was conducted in Medline and supplemented by hand searching, incorporating published studies in English with full text available. Inclusion/exclusion decisions and data extraction were completed in duplicate. Exposures included three categories of risk factors and four categories of antecedents, with case and comparison groups defined by adult psychiatric diagnosis. Effect sizes and prevalence rates were extracted, where available, and the strength of evidence synthesised and evaluated qualitatively across the study designs.ResultsOf 1775 studies identified by the search, 127 provided data to the review. Individuals who develop SSD experience a diversity of subtle premorbid developmental deficits and risk exposures, spanning the prenatal period through early adolescence. Those of greatest magnitude (or observed most consistently) 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. Relatively less evidence has accumulated to implicate this diversity of exposures in AP, and many yet remain unexamined, with the most consistent or strongest evidence to date being for obstetric complications, psychopathology, cognitive indicators and motor dysfunction. Among the few investigations affording direct comparison between SSD and AP, larger effect sizes and a greater number of significant associations are commonly reported for SSD relative to AP.ConclusionsShared risk factors for SSD and AP may include obstetric complications, childhood psychopathology, cognitive markers and motor dysfunction, but the capacity to distinguish common versus distinct risk factors/antecedents for SSD and AP is limited by the scant availability of prospective data for AP, and inconsistency in replication. Further studies considering both diagnoses concurrently are needed. Nonetheless, the prevalence of the risk factors/antecedents observed in cases and controls helps demarcate potential targets for preventative interventions for these disorders.

New South Wales Child Development Study (NSW-CDS): an Australian multiagency, multigenerational, longitudinal record linkage study

Purpose The initial aim of this multiagency, multigenerational record linkage study is to identify childhood profiles of developmental vulnerability and resilience, and to identify the determinants of these profiles. The eventual aim is to identify risk and protective factors for later childhood-onset and adolescent-onset mental health problems, and other adverse social outcomes, using subsequent waves of record linkage. The research will assist in informing the development of public policy and intervention guidelines to help prevent or mitigate adverse long-term health and social outcomes. Participants The study comprises a population cohort of 87 026 children in the Australian State of New South Wales (NSW). The cohort was defined by entry into the first year of full-time schooling in NSW in 2009, at which time class teachers completed the Australian Early Development Census (AEDC) on each child (with 99.7% coverage in NSW). The AEDC data have been linked to the childrens birth, health, school and child protection records for the period from birth to school entry, and to the health and criminal records of their parents, as well as mortality databases. Findings to date Descriptive data summarising sex, geographic and socioeconomic distributions, and linkage rates for the various administrative databases are presented. Child data are summarised, and the mental health and criminal records data of the childrens parents are provided. Future plans In 2015, at age 11 years, a self-report mental health survey was administered to the cohort in collaboration with government, independent and Catholic primary school sectors. A second record linkage, spanning birth to age 11 years, will be undertaken to link this survey data with the aforementioned administrative databases. This will enable a further identification of putative risk and protective factors for adverse mental health and other outcomes in adolescence, which can then be tested in subsequent record linkages.

Birth outcomes and academic achievement in childhood: A population record linkage study

Poor academic performance during childhood predicts later adverse outcomes, and could be targeted for improvement if detected early. This study used population-based record linkage to examine the association between early life risk factors and academic achievement at two different stages of development using two different cohorts: a kindergarten (~age 5 years) and a grade 3 cohort (~age 8 years). Similar factors were predictive of academic performance in both age groups, including positive effects of increasing maternal age and lack of maternal prenatal smoking. Female sex was associated with higher scores for literacy. The results suggest that children with less developed academic skills can be identified earlier, with effective programmes to enhance academic skills needed during the first year of school to enhance subsequent results.

The impact of parental offending on offspring aggression in early childhood: A population-based record linkage study

PurposeTo examine the impact of parental criminal offending, both paternal and maternal, on offspring aggression at age 5 years, while also considering key risk factors, including parental mental illness, child’s sex, and socioeconomic disadvantage.MethodsThe sample comprised 69,116 children, with linked parental information, from the New South Wales Child Development Study, a population-based multi-agency, multi-generational record linkage study that combines information from a teacher-reported cross-sectional survey of early childhood development at age 5 years (the 2009 Australian Early Development Census; AEDC) with data obtained via administrative records from multiple sources (e.g., health, crime, education, and welfare). Hierarchical logistic regression analyses were conducted to determine the effects of maternal and paternal criminal court appearances (frequency and type of offending), and mental health service contacts, on offspring aggression measured in the AEDC.ResultsHaving a parent with a history of offending was significantly associated with high levels of offspring aggression in early childhood. The strength of association was greatest when parents were involved in frequent (≥6 offences: adjusted odds ratio [aOR] range = 1.55–1.73) and violent (aOR range = 1.49–1.63) offending. Both maternal and paternal offending remained significant predictors of offspring aggression after accounting for parental mental illness, and associations were similar in magnitude for maternal and paternal offending histories.ConclusionsParental history of severe criminal offending increased the risk of high levels of aggression in offspring during early childhood, highlighting the need for intervention with families during this key developmental period.

Pervasive influence of maternal and paternal criminal offending on early childhood development: A population data linkage study

Background Parental criminal offending is an established risk factor for offending among offspring, but little evidence is available indicating the impact of offending on early childhood functioning. We used data from a large Australian population cohort to determine associations between exposure to parental offending and a range of developmental outcomes at age 5 years. Method Multi-generation data in 66 477 children and their parents from the New South Wales Child Development Study were combined using data linkage. Logistic and multinomial regressions tested associations between any and violent offending histories of parents (fathers, mothers, or both parents) obtained from official records, and multiple measures of early childhood developmental functioning (social, emotional–behavioural, cognitive, communication and physical domains) obtained from the teacher-reported 2009 Australian Early Development Census. Results Parental offending conferred significantly increased risk of vulnerability on all domains, particularly the cognitive domain. Greater risk magnitudes were observed for offending by both parents and by mothers than by fathers, and for violent than for any offending. For all parental offending exposures, vulnerability on multiple domains (where medium to large effects were observed) was more likely than on a single domain (small to medium effects). Relationships remained significant and of comparable magnitude following adjustment for sociodemographic covariates. Conclusions The effect of parental offending on early childhood developmental outcomes is pervasive, with the strongest effects on functioning apparent when both parents engage in violent offending. Supporting affected families in early childhood might mitigate both early developmental vulnerability and the propensity for later delinquency among these offspring.

The 2015 Middle Childhood Survey (MCS) of mental health and well-being at age 11 years in an Australian population cohort

Purpose The Middle Childhood Survey (MCS) was designed as a computerised self-report assessment of children’s mental health and well-being at approximately 11 years of age, conducted with a population cohort of 87 026 children being studied longitudinally within the New South Wales (NSW) Child Development Study. Participants School Principals provided written consent for teachers to administer the MCS in class to year 6 students at 829 NSW schools (35.0% of eligible schools). Parent or child opt-outs from participation were received for 4.3% of children, and MCS data obtained from 27 808 children (mean age 11.5 years, SD 0.5; 49.5% female), representing 85.9% of students at participating schools. Findings to date Demographic characteristics of participating schools and children are representative of the NSW population. Children completed items measuring 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. Distributions of responses on each item and construct demarcate competencies and vulnerabilities within the population: most children report mental health and well-being, but the population distribution spanned the full range of possible scores on every construct. Future plans Multiagency, intergenerational linkage of the MCS data with health, education, child protection, justice and early childhood development records took place late in 2016. Linked data were used to elucidate patterns of risk and protection across early and middle child development, and these data will provide a foundation for future record linkages in the cohort that will track mental and physical health, social and educational/occupational outcomes into adolescence and early adulthood.

Hospital admission for infection during early childhood influences developmental vulnerabilities at age 5 years

Childhood infectious diseases can be associated with later physical and psychological ill health, and the effects of this association may be evident during early childhood development. This study aimed to examine the effects of hospitalisation for early life infection on early childhood development.

Latent profiles of early developmental vulnerabilities in a New South Wales child population at age 5 years

Objective: Detecting the early emergence of childhood risk for adult mental disorders may lead to interventions for reducing subsequent burden of these disorders. We set out to determine classes of children who may be at risk for later mental disorder on the basis of early patterns of development in a population cohort, and associated exposures gleaned from linked administrative records obtained within the New South Wales Child Development Study. Methods: Intergenerational records from government departments of health, education, justice and child protection were linked with the Australian Early Development Census for a state population cohort of 67,353 children approximately 5 years of age. We used binary data from 16 subdomains of the Australian Early Development Census to determine classes of children with shared patterns of Australian Early Development Census–defined vulnerability using latent class analysis. Covariates, which included demographic features (sex, socioeconomic status) and exposure to child maltreatment, parental mental illness, parental criminal offending and perinatal adversities (i.e. birth complications, smoking during pregnancy, low birth weight), were examined hierarchically within latent class analysis models. Results: Four classes were identified, reflecting putative risk states for mental disorders: (1) disrespectful and aggressive/hyperactive behaviour, labelled ‘misconduct risk’ (N = 4368; 6.5%); (2) ‘pervasive risk’ (N = 2668; 4.0%); (3) ‘mild generalised risk’ (N = 7822; 11.6%); and (4) ‘no risk’ (N = 52,495; 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, with distinguishable patterns of association for some covariates. Conclusion: Patterns of early childhood developmental vulnerabilities may provide useful indicators for particular mental disorder outcomes in later life, although their predictive utility in this respect remains to be established in longitudinal follow-up of the cohort.

Effects of maltreatment and parental schizophrenia spectrum disorders on early childhood social-emotional functioning: a population record linkage study

Aims. Childhood maltreatment and a family history of a schizophrenia spectrum disorder (SSD) are each associated with social-emotional dysfunction in childhood. Both are also strong risk factors for adult SSDs, and social-emotional dysfunction in childhood may be an antecedent of these disorders. We used data from a large Australian population cohort to determine the independent and moderating effects of maltreatment and parental SSDs on early childhood social-emotional functioning. Methods. The New South Wales Child Development Study combines intergenerational multi-agency data using record linkage methods. Multiple measures of social-emotional functioning (social competency, prosocial/helping behaviour, anxious/fearful behaviour; aggressive behaviour, and hyperactivity/inattention) on 69 116 kindergarten children (age ~5 years) were linked with government records of child maltreatment and parental presentations to health services for SSD. Multivariable analyses investigated the association between maltreatment and social-emotional functioning, adjusting for demographic variables and parental SSD history, in the population sample and in sub-cohorts exposed and not exposed to parental SSD history. We also examined the association of parental SSD history and social-emotional functioning, adjusting for demographic variables and maltreatment. Results. Medium-sized associations were identified between maltreatment and poor social competency, aggressive behaviour and hyperactivity/inattention; small associations were revealed between maltreatment and poor prosocial/helping and anxious/fearful behaviours. These associations did not differ greatly when adjusted for parental SSD, and were greater in magnitude among children with no history of parental SSD. Small associations between parental SSD and poor social-emotional functioning remained after adjusting for demographic variables and maltreatment. Conclusions. Childhood maltreatment and history of parental SSD are associated independently with poor early childhood social-emotional functioning, with the impact of exposure to maltreatment on social-emotional functioning in early childhood of greater magnitude than that observed for parental SSDs. The impact of maltreatment was reduced in the context of parental SSDs. The influence of parental SSDs on later outcomes of maltreated children may become more apparent during adolescence and young adulthood when overt symptoms of SSD are likely to emerge. Early intervention to strengthen childhood social-emotional functioning might mitigate the impact of maltreatment, and potentially also avert future psychopathology.

Cohort Profile: The New South Wales Child Development Study (NSW-CDS)—Wave 2 (child age 13 years)

The New South Wales Child Development Study (NSW-CDS) was established to enable a life course epidemiological approach to identifying risk and protective factors for childhood and adolescent-onset mental health problems, and other adverse outcomes (e.g. educational underachievement, welfare dependence, criminality). The study methodology entails repeated waves of record linkage for a population of Australian children in the state of NSW, funded by competitive funding awards (see Funding), and conducted in partnership with multiple NSW government departments. Table 1 summarizes the study phases (waves of record linkage) and measurements...