Optimal early cognitive and emotional development are vital to reaching one’s full potential and represent our best chance to improve the mental health of the population. The developmental origins of health and disease (DOHaD) hypothesis posits that adverse perinatal exposures can alter physiology and increase disease risk. As physiological plasticity decreases with age, interventions applied during gestation may hold the most promise for reducing the impact of mental disorders across the lifespan. However, this vast clinical potential remains largely unrealized as the majority of human DOHaD research is observational in nature. The application of more rigorous experimental designs [e.g. Randomized Controlled Trials (RCTs)] not only represents a major step toward unlocking this potential, but are required to fully test the scientific validity of the DOHaD hypothesis as it pertains to mental illness. Here, we argue that the optimization of maternal diet and exercise during pregnancy represents our best chance to improve offspring neurodevelopment and reduce the burden of mental disorders. Follow-up studies of the offspring of pregnant women enrolled in new and existing RCTs of maternal gestational nutrition+exercise interventions are required to determine if acting during pregnancy can prevent and/or meaningfully reduce the prevalence and severity of mental disorders in the population.

In general population samples, better childhood cognitive functioning is associated with decreased risk of depression in adulthood. However, this link has not been examined in extremely low birth weight survivors (ELBW, <1000 g), a group known to have poorer cognition and greater depression risk. This study assessed associations between cognition at age 8 and lifetime risk of major depressive disorder in 84 ELBW survivors and 90 normal birth weight (NBW, ⩾2500 g) individuals up to 29–36 years of age. The Wechsler Intelligence Scale for Children, Revised (WISC-R), Raven’s Coloured Progressive Matrices and the Token Test assessed general, fluid, and verbal intelligence, respectively, at 8 years of age. Lifetime major depressive disorder was assessed using the Mini International Neuropsychiatric Interview at age 29–36 years. Associations were examined using logistic regression adjusted for childhood socioeconomic status, educational attainment, age, sex, and marital status. Neither overall intelligence quotient (IQ) [WISC-R Full-Scale IQ, odds ratios (OR)=0.87, 95% confidence interval (CI)=0.43–1.77], fluid intelligence (WISC-R Performance IQ, OR=0.98, 95% CI=0.48–2.00), nor verbal intelligence (WISC-R Verbal IQ, OR=0.81, 95% CI=0.40–1.63) predicted lifetime major depression in ELBW survivors. However, every standard deviation increase in WISC-R Full-Scale IQ (OR=0.43, 95% CI=0.20–0.92) and Performance IQ (OR=0.46, 95% CI=0.21–0.97), and each one point increase on the Token Test (OR=0.80, 95% CI=0.67–0.94) at age 8 was associated with a reduced risk of lifetime depression in NBW participants. Higher childhood IQ, better fluid intelligence, and greater verbal comprehension in childhood predicted reduced depression risk in NBW adults. Our findings suggest that ELBW survivors may be less protected by superior cognition than NBW individuals.

Preterm birth and exposure to childhood sexual abuse (CSA) are early physiological and psychological adversities that have been linked to reduced social functioning across the lifespan. However, the joint effects of being born preterm and being exposed to CSA on adult social outcomes remains unclear. We sought to determine the impact of exposure to both preterm birth and CSA on adult social functioning in a group of 179 extremely low birth weight (ELBW; <1000 g) survivors and 145 matched normal birth weight (>2500 g) participants in the fourth decade of life. Social outcome data from a prospective, longitudinal, population-based Canadian birth cohort initiated between the years of 1977 and 1982 were examined. At age 29–36 years, ELBW survivors who experienced CSA reported poorer relationships with their partner, worse family functioning, greater loneliness, lower self-esteem and had higher rates of avoidant personality problems than those who had not experienced CSA. Birth weight status was also found to moderate associations between CSA and self-esteem (P=0.032), loneliness (P=0.021) and family functioning (P=0.060), such that the adverse effects of CSA were amplified in ELBW survivors. Exposure to CSA appears to augment the adult social risks associated with perinatal adversity. Individuals born preterm and exposed to CSA appear to be a group at particularly high risk for adverse social outcomes in adulthood.

Transgenerational transmission refers to positive and negative adaptations in brain function and behavior that affect following generations. In this paper, empirical findings regarding the transgenerational transmission of maternal adversity during three critical periods – childhood, pregestational adulthood and pregnancy – will be reviewed in terms of pregnancy outcomes, maternal care, offspring behavior and development, and physiological functioning. Research on the transgenerational transmission of enrichment and the implications for interventions to ameliorate the consequences of adversity will also be presented. In the final section, underlying epigenetic and environmental mechanisms that have been proposed to explain how experience is transferred across generations through transgenerational transmission will be reviewed. Directions for future research are suggested throughout.

Studies of the role of the early environment in shaping children’s risk for anxiety problems have produced mixed results. It is possible that inconsistencies in previous findings result from a lack of consideration of a putative role for inherited influences moderators on the impact of early experiences. Early inherited influences not only contribute to vulnerabilities for anxiety problems throughout the lifespan, but can also modulate the ways that the early environment impacts child outcomes. In the current study, we tested the effects of child-centered parenting behaviors on putative anxiety risk in young children who differed in levels of inherited vulnerability. We tested this using a parent–offspring adoption design and a sample in which risk for anxiety problems and parenting behaviors were assessed in both mothers and fathers. Inherited influences on anxiety problems were assessed as anxiety symptoms in biological parents. Child-centered parenting was observed in adoptive mothers and fathers when children were 9 months old. Social inhibition, an early temperament marker of anxiety risk, was observed at child ages 9 and 18 months. Inherited influences on anxiety problems moderated the link between paternal child-centered parenting during infancy and social inhibition in toddlerhood. For children whose birth parents reported high levels of anxiety symptoms, greater child-centered parenting in adoptive fathers was related to greater social inhibition 9 months later. For children whose birth parents reported low levels of anxiety symptoms, greater child-centered parenting in adoptive fathers was related to less social inhibition across the same period.

Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a complex developmental disorder with serious medical, cognitive and emotional symptoms across the lifespan. This genetic deletion also imparts a lifetime risk for developing schizophrenia that is 25–30 times that of the general population. The origin of this risk is multifactorial and may include dysregulation of the stress response and immunological systems in relation to brain development. Vitamin D is involved in brain development and neuroprotection, gene transcription, immunological regulation and influences neuronal signal transduction. Low levels of vitamin D are associated with schizophrenia, depression and anxiety in the general population. Yet, little is known about how vitamin D levels in children with 22q11.2DS could mediate risk of psychosis in adulthood. Blood plasma levels of vitamin D were measured in children aged 7–16 years with (n=11) and without (n=16) 22q11.2DS in relation to parent reports of children’s anxiety and atypicality. Anxiety and atypicality in childhood are risk indicators for the development of schizophrenia in those with 22q11.2DS and the general population. Children with 22q11.2DS had lower vitamin D levels, as well as elevated anxiety and atypicality compared with typical peers. Higher levels of anxiety, depression and internalizing problems but not atypicality were associated with lower levels of vitamin D. Vitamin D insufficiency may relate to higher levels of anxiety and depression, in turn contributing to the elevated risk of psychosis in this population. Further study is required to determine casual linkages between anxiety, stress, mood and vitamin D in children with 22q11.2DS.