Prenatal famine exposure and mental health in later midlife

Bridging the gap: Prenatal nutrition, myelination, and schizophrenia etiopathogenesis

Schizophrenia (SZ) is a complex mental illness characterized by disturbances in thinking, emotionality, and behavior, significantly impacting the quality of life for individuals affected and those around them. The etiology of SZ involves intricate interactions between genetic and environmental factors, although the precise mechanisms remain incompletely understood. Genetic predisposition, neurotransmitter dysregulation (particularly involving dopamine and serotonin), and structural brain abnormalities, including impaired prefrontal cortex function, have been implicated in SZ development. However, increasing evidence reveals the role of environmental factors, such as nutrition, during critical periods like pregnancy and lactation. Epidemiological studies suggest that early malnutrition significantly increases the risk of SZ symptoms manifesting in late adolescence, a crucial period coinciding with peak myelination and brain maturation. Prenatal undernutrition may disrupt myelin formation, rendering individuals more susceptible to SZ pathology. This review explores the potential relationship between prenatal undernutrition, myelin alterations, and susceptibility to SZ. By delineating the etiopathogenesis, examining genetic and environmental factors associated with SZ, and reviewing the relationship between SZ and myelination disorders, alongside the impact of malnutrition on myelination, we aim to examine how malnutrition might be linked to SZ by altering myelination processes, which contribute to increasing the understanding of SZ etiology and help identify targets for intervention and management.

Association between gestational weight gain and behavioral problems of the offspring aged 6-7 years: A population-based study in Japan

OBJECTIVE

To identify the optimal gestational weight gain (GWG) thresholds for behavioral problems and prosocial behavior in 6- to 7-year-old children.

METHODS

A retrospective cohort study was conducted using data from the Adachi Child Health Impact of Living Difficulty study, including all first-graders in public schools in Adachi, Tokyo, in 2017, 2019, and 2021 (n = 11 048, response rate = 80.1%). GWG was based on clinical records in the Mother and Child Health Handbook. Total difficulties and prosocial behavior were assessed using the Strength and Difficulties Questionnaire. Logistic regression models with restricted cubic splines, and quintile categories were employed to examine the association of GWG with the clinical range of total difficulties and prosocial behavior, controlling for covariates.

RESULTS

The association between GWG and total difficulties exhibited a reverse J-shaped pattern, with low GWG, but not high GWG, increasing the risk (odds ratio [OR] 1.20, 95% confidence interval [CI] 1.01-1.42, P = 0.039 for GWG < 7 kg; OR 1.03, 95% CI 0.85-1.24, P = 0.786 for GWG > 14 kg), referencing the median (10 kg). High GWG was associated with a lower risk of problems in prosocial behavior (OR = 0.77, 95% CI 0.62-0.95, P = 0.017 for GWG > 14 kg; OR 1.06, 95% CI 0.88-1.27, P = 0.532 for GWG <7 kg).

CONCLUSION

GWG less than 7 kg may increase the risk of total difficulties, whereas GWG over 14 kg may serve as a protective factor for prosocial behavior in 6- to 7-year-old children.

The social determinants of mental health and disorder: evidence, prevention and recommendations

People exposed to more unfavourable social circumstances are more vulnerable to poor mental health over their life course, in ways that are often determined by structural factors which generate and perpetuate intergenerational cycles of disadvantage and poor health. Addressing these challenges is an imperative matter of social justice. In this paper we provide a roadmap to address the social determinants that cause mental ill health. Relying as far as possible on high-quality evidence, we first map out the literature that supports a causal link between social determinants and later mental health outcomes. Given the breadth of this topic, we focus on the most pervasive social determinants across the life course, and those that are common across major mental disorders. We draw primarily on the available evidence from the Global North, acknowledging that other global contexts will face both similar and unique sets of social determinants that will require equitable attention. Much of our evidence focuses on mental health in groups who are marginalized, and thus often exposed to a multitude of intersecting social risk factors. These groups include refugees, asylum seekers and displaced persons, as well as ethnoracial minoritized groups; lesbian, gay, bisexual, transgender and queer (LGBTQ+) groups; and those living in poverty. We then introduce a preventive framework for conceptualizing the link between social determinants and mental health and disorder, which can guide much needed primary prevention strategies capable of reducing inequalities and improving population mental health. Following this, we provide a review of the evidence concerning candidate preventive strategies to intervene on social determinants of mental health. These interventions fall broadly within the scope of universal, selected and indicated primary prevention strategies, but we also briefly review important secondary and tertiary strategies to promote recovery in those with existing mental disorders. Finally, we provide seven key recommendations, framed around social justice, which constitute a roadmap for action in research, policy and public health. Adoption of these recommendations would provide an opportunity to advance efforts to intervene on modifiable social determinants that affect population mental health.

The early life exposome and autism risk: a role for the maternal microbiome?

Autism spectrum disorders (ASD) are highly heritable, heterogeneous neurodevelopmental disorders characterized by clinical presentation of atypical social, communicative, and repetitive behaviors. Over the past 25 years, hundreds of ASD risk genes have been identified. Many converge on key molecular pathways, from translational control to those regulating synaptic structure and function. Despite these advances, therapeutic approaches remain elusive. Emerging data unearthing the relationship between genetics, microbes, and immunity in ASD suggest an integrative physiology approach could be paramount to delivering therapeutic breakthroughs. Indeed, the advent of large-scale multi-OMIC data acquisition, analysis, and interpretation is yielding an increasingly mechanistic understanding of ASD and underlying risk factors, revealing how genetic susceptibility interacts with microbial genetics, metabolism, epigenetic (re)programming, and immunity to influence neurodevelopment and behavioral outcomes. It is now possible to foresee exciting advancements in the treatment of some forms of ASD that could markedly improve quality of life and productivity for autistic individuals. Here, we highlight recent work revealing how gene X maternal exposome interactions influence risk for ASD, with emphasis on the intrauterine environment and fetal neurodevelopment, host-microbe interactions, and the evolving therapeutic landscape for ASD.

A Link between Prenatal Stage of Life during the Great Chinese Famine and Subsequent Depressive Symptoms among Middle-Aged and Older Adults

Prenatal malnutrition may increase the risk of depressive symptoms in adulthood. This study investigated the association between prenatal exposure to malnutrition with risk of depressive symptoms in middle-aged and older adults using the Chinese Great Famine of 1959-1961 as a natural experiment. Data were obtained from the China Health and Retirement Longitudinal Study baseline survey (2011). A total of 5391 individuals born from 1956 to 1965 were included in the study. Depressive symptoms were ascertained via the Center for Epidemiological Studies Depression Scale short form. Famine severity was measured using the cohort size shrinkage index. Difference-in-differences models were used to explore the association between prenatal famine exposure and later-life depressive symptoms. Compared with the post-famine cohort (1963-1965), famine cohorts (1959-1962) were 4.74 times (95% CI = 1.28-8.20) as likely to develop depressive symptoms. The stratified analysis found that prenatal exposure to famine was associated with depressive symptoms in rural residents but not those living in urban areas. In rural females, prenatal malnutrition was associated with a higher risk of depressive symptoms. However, there was no significant association between prenatal malnutrition and depressive symptoms in rural males. Our results indicated that prenatal malnutrition may contribute to a higher risk for depressive symptoms in later life among female rural residents.

The association between prenatal famine, DNA methylation and mental disorders: a systematic review and meta-analysis

BACKGROUND

Undernutrition in pregnant women is an unfavorable environmental condition that can affect the intrauterine development via epigenetic mechanisms and thus have long-lasting detrimental consequences for the mental health of the offspring later in life. One epigenetic mechanism that has been associated with mental disorders and undernutrition is alterations in DNA methylation. The effect of prenatal undernutrition on the mental health of adult offspring can be analyzed through quasi-experimental studies such as famine studies. The present systematic review and meta-analysis aims to analyze the association between prenatal famine exposure, DNA methylation, and mental disorders in adult offspring. We further investigate whether altered DNA methylation as a result of prenatal famine exposure is prospectively linked to mental disorders.

METHODS

We conducted a systematic search of the databases PubMed and PsycINFO to identify relevant records up to September 2022 on offspring whose mothers experienced famine directly before and/or during pregnancy, examining the impact of prenatal famine exposure on the offspring's DNA methylation and/or mental disorders or symptoms.

RESULTS

The systematic review showed that adults who were prenatally exposed to famine had an increased risk of schizophrenia and depression. Several studies reported an association between prenatal famine exposure and hyper- or hypomethylation of specific genes. The largest number of studies reported differences in DNA methylation of the IGF2 gene. Altered DNA methylation of the DUSP22 gene mediated the association between prenatal famine exposure and schizophrenia in adult offspring. Meta-analysis confirmed the increased risk of schizophrenia following prenatal famine exposure. For DNA methylation, meta-analysis was not suitable due to different microarrays/data processing approaches and/or unavailable data.

CONCLUSION

Prenatal famine exposure is associated with an increased risk of mental disorders and DNA methylation changes. The findings suggest that changes in DNA methylation of genes involved in neuronal, neuroendocrine, and immune processes may be a mechanism that promotes the development of mental disorders such as schizophrenia and depression in adult offspring. Such findings are crucial given that undernutrition has risen worldwide, increasing the risk of famine and thus also of negative effects on mental health.

The impact of adversities across the lifespan on psychological symptom profiles in late adulthood: a latent profile analysis

People commonly face adverse circumstances throughout life, which increases risk for psychiatric disorders, such as anxiety, depression, psychosis, and posttraumatic stress disorder (PTSD). Adversities may occur during different periods in life. Especially adversity during early periods has been suggested to put individuals at risk for adverse mental health outcomes. Here, we investigated whether timing of adversity during the prenatal period, childhood, or mid-to-late adulthood differentially impacted classification into late adulthood symptom profiles. We performed sex-stratified Latent Profile Analysis to identify latent profiles regarding anxious, depressive, psychotic, and PTSD symptoms in n = 568 Dutch famine birth cohort members (n = 294 women, n = 274 men, mean age(SD) = 72.9(0.8)). Cross-sectional late adulthood symptomatology, childhood traumatic maltreatment, and adulthood trauma were based on self-report questionnaires. Prenatal adversity was considered present when individuals were prenatally exposed to the 1944-45 Dutch famine. In both men and women we identified one anxious/depressive profile and three profiles with approximately equal severity of all symptom types within each profile, yet differentiating in overall severity (low, mild, high) between profiles. We additionally found a PTSD symptom profile in women. In men, logistic regression models showed significant associations between prenatal, childhood and adulthood adversity, and profile classification, with differential effects depending on timing and most profound effects of child maltreatment. In women, childhood and adulthood adversity significantly increased classification probability into almost all profiles, with no significant effect of prenatal adversity. These findings support a time-dependent and sex-specific impact of adversity during different periods across the lifespan on psychological health, with consequences into late adulthood.

Lessons learned from 25 Years of Research into Long term Consequences of Prenatal Exposure to the Dutch famine 1944-45: The Dutch famine Birth Cohort

This paper describes the findings of a historical cohort study of men and women born around the time of the Dutch famine 1944-45. It provided the first direct evidence in humans of the lasting consequences of prenatal undernutrition. The effects of undernutrition depended on its timing during gestation, and the organs and tissues undergoing periods of rapid development at that time. Early gestation appeared to be particularly critical, with the effects of undernutrition being most apparent, even without reductions in size at birth. Undernutrition during gestation affected the structure and function of organs and tissues, altered behaviour and increased risks of chronic degenerative diseases. This demonstrates the fundamental importance of maternal nutrition during gestation as the building blocks for future health.

Undernutrition when young and the risk of poor renal function in adulthood in women with diabetes in Shanghai, China

Objective

To evaluate the effect of undernutrition when young on the risk of poor renal function in adulthood in women with diabetes mellitus.

Methods

We studied diabetic women born between 1921 and 1958 who were exposed to the 1959-to-1962 Chinese famine when they were 0 to 37 years old. Exposure age was classified as young adulthood (18 to 37 years), adolescence (10 to 17 years), or childhood (0 to 9 years). The Adolescence group, which was provided with the largest amount of food during the famine, was used as the control group, and variance and binary logistic regression analyses were performed.

Results

The prevalences of low estimated glomerular filtration rate (eGFR) in the Childhood, Adolescence, and Young adulthood groups were 5.26%, 22.39%, and 79.24%, respectively. The risk of low eGFR for the Young adulthood group (odds ratio [OR] 1.65, 95% confidence interval [CI] 1.10, 2.48), but not for the Childhood group (OR 1.10, 95% CI 0.68, 1.78), was higher than that for the Adolescence group after adjustment for potential confounders.

Conclusions

Undernutrition during young adulthood significantly increases the risk of renal dysfunction in adult women with diabetes. Therefore, the nutrition of less affluent young women should be improved.

The Importance of Childhood for Adult Health and Development-Study Protocol of the Zurich Longitudinal Studies

Evidence is accumulating that individual and environmental factors in childhood and adolescence should be considered when investigating adult health and aging-related processes. The data required for this is gathered by comprehensive long-term longitudinal studies. This article describes the protocol of the Zurich Longitudinal Studies (ZLS), a set of three comprehensive cohort studies on child growth, health, and development that are currently expanding into adulthood. Between 1954 and 1961, 445 healthy infants were enrolled in the first ZLS cohort. Their physical, motor, cognitive, and social development and their environment were assessed comprehensively across childhood, adolescence, and into young adulthood. In the 1970s, two further cohorts were added to the ZLS and assessed with largely matched study protocols: Between 1974 and 1979, the second ZLS cohort included 265 infants (103 term-born and 162 preterm infants), and between 1970 and 2002, the third ZLS cohort included 327 children of participants of the first ZLS cohort. Since 2019, the participants of the three ZLS cohorts have been traced and invited to participate in a first wave of assessments in adulthood to investigate their current health and development. This article describes the ZLS study protocol and discusses opportunities, methodological and conceptual challenges, and limitations arising from a long-term longitudinal cohort recruited from a study about development in early life. In the future, the ZLS will provide data to investigate childhood antecedents of adult health outcomes and, ultimately, will help respond to the frequent call of scientists to shift the focus of aging research into the first decades of life and, thus, to take a lifespan perspective on aging.

Early-life exposure to famine and late-life depression: Does leukocyte telomere length mediate the association?

BACKGROUND

A positive association between early-life famine exposure and depression has been demonstrated. However, the mechanisms by which famine exposure in early life leads to late-life depression remains unclear. The present study examines the impact of leukocyte telomere length (LTL) and/or religiosity on the relationship between early-life famine exposure and late-life depression in a Chinese minority sample.

METHODS

A cross-sectional study of community-dwelling adults aged 55 or older was conducted in the Ningxia province of western China from 2013 to 2016. Multivariate ordinal logistic regression was used to examine the association between famine exposure and depression status, and a series mediation model was constructed to identify the mediation role of LTL and religiosity.

RESULTS

Compared with famine exposure during adulthood, fetal famine exposure was associated with a higher risk of late-life depression (adjusted odds ratio of 3.17, 95% CI: 1.36-7.38). A cumulative effect of fetal famine exposure on the risk of late-life depression was observed. Participants born in 1961 (the third year of the famine) had the strongest association with late-life depression. LTL played a mediating role in the association between famine exposure and depression which accounted for 21% of the total effect.

LIMITATIONS

The cross-sectional design prevents causal inferences regarding the relationships between famine and depression.

CONCLUSIONS

Fetal famine exposure was associated with an increased risk of late-life depression in a Chinese minority community-dwelling population. Telomere shortening partially mediated this association.

Epigenetic variations due to nutritional status in early-life and its later impact on aging and disease

Epigenetics refers to changes in gene function, not resulting from the primary DNA sequence, influenced by the environment. It provides a link between the molecular regulation of the genome and the environmental signals exposed during the life of individuals (including lifestyle, social behavior, development, and nutrition). Notably, early development (intrauterine or postnatal) is highly influenced by the adverse socioeconomic status that leads to malnutrition or obesity; these conditions induce changes over the fetal epigenetic programming and can be transferred by transgenerational inheritance, inducing alterations of the transcription of genes related to several metabolic and neurological processes. Moreover, obesity during pregnancy, and excessive gestational weight gain are associated with an increased risk of fatal pregnancy complications, and adverse cardio-metabolic, respiratory and cognitive-related outcomes of the future child. However, most of our knowledge in this field comes from experimental animal models, that partially resemble the nutritional effects of humans. In this context, nutritional effects implicated in historical famines represent valuable information about the transgenerational effects of undernutrition and stress. In the present review, we attempt to describe the most outstanding results from the most studied famines about the impact of malnutrition on the epigenome.

Using Openly Accessible Resources to Strengthen Causal Inference in Epigenetic Epidemiology of Neurodevelopment and Mental Health

The recent focus on the role of epigenetic mechanisms in mental health has led to several studies examining the association of epigenetic processes with psychiatric conditions and neurodevelopmental traits. Some studies suggest that epigenetic changes might be causal in the development of the psychiatric condition under investigation. However, other scenarios are possible, e.g., statistical confounding or reverse causation, making it particularly challenging to derive conclusions on causality. In the present review, we examine the evidence from human population studies for a possible role of epigenetic mechanisms in neurodevelopment and mental health and discuss methodological approaches on how to strengthen causal inference, including the need for replication, (quasi-)experimental approaches and Mendelian randomization. We signpost openly accessible resources (e.g., "MR-Base" "EWAS catalog" as well as tissue-specific methylation and gene expression databases) to aid the application of these approaches.