Youth genetic vulnerability to maternal depressive symptoms: 5-HTTLPR as moderator of intergenerational transmission effects in a multiwave prospective study

Perinatal maternal depressive symptoms and risk of behavioral problems at five years

BACKGROUND

Evidence on the association between perinatal maternal depression and children's behavioral development is limited. We investigated the association between maternal depressive symptoms during pregnancy and postpartum and the risk of childhood behavioral problems using data from a birth cohort study.

METHODS

Study subjects were 1199 mother-child pairs. Maternal depressive symptoms were assessed with the Center for Epidemiologic Studies Depression Scale during pregnancy and the Edinburgh Postnatal Depression Scale at 4 months postpartum. Children's behavioral development at 5 years of age was assessed with the Strengths and Difficulties Questionnaire.

RESULTS

Compared with children whose mothers did not experience depressive symptoms during pregnancy, those whose mothers did experience depressive symptoms during pregnancy had increased risk of emotional symptoms, conduct problems, hyperactivity, peer problems, and low prosocial behavior. Maternal depressive symptoms at around 4 months postpartum were associated with increased risk of childhood emotional problems. Compared with children whose mothers did not experience depressive symptoms during the perinatal period, those whose mothers did experience depressive symptoms both during pregnancy and postpartum had a fivefold increased risk of childhood emotional symptoms and a threefold increased risk of peer problems.

CONCLUSIONS

Our findings suggest that perinatal maternal depression is associated with behavioral problems in children.

IMPACT

Several epidemiological studies in Western countries have examined the association between perinatal maternal depression and children's behavioral development, yet the results are conflicting and inconclusive. There is limited evidence on this topic in Asia. In our study using data from a prospective pregnancy birth cohort, maternal depressive symptoms around 4 months postpartum were associated with an increased risk of emotional symptoms in children aged 5 years. Children whose mothers had exhibited depressive symptoms both during pregnancy and postpartum had a fivefold increased risk of childhood emotional symptoms and a threefold increased risk of peer problems.

Longitudinal Coupling of Depression in Parent-Adolescent Dyads: Within- and Between-Dyad Effects Over Time

The present work evaluated reciprocal, within-dyad associations between parent-adolescent depressive symptoms across two independent samples (N=327 and N=435 dyads, respectively; approximately 85% biological mothers) assessed every three months for two (Study 1) to three (Study 2) years. Results of random intercept cross-lagged panel models converged to support positive contemporaneous patterns of co-fluctuation in parent and adolescent depression, such that within-person deviations in parental depression were associated with same direction within-person deviations in adolescent depression at the same timepoint. In contrast, within-person fluctuations in parent depression did not predict prospective within-person fluctuations in adolescent depression, or vice versa, across the follow-up period. Results held across boys and girls, as well as dyads with and without a parental history of depressive disorder. Overall, findings advance knowledge by demonstrating that, after accounting for between-person/dyad variance, parent and adolescent depression demonstrate contemporaneous co-fluctuations, but do not demonstrate within-dyad reciprocity over time.

Metabolomic evidence for the therapeutic effect of gentiopicroside in a corticosterone-induced model of depression

BACKGROUND

Depression is a disease that seriously threatens the quality of human life. To explore the effect of gentiopicroside on depression, this study investigated the therapeutic effect of gentiopicroside on corticosterone-induced depressionin vivo and in vitro by using metabolomic methods.

METHODS

A total of 36 rats were randomly assigned to three groups: a normal group, model group (depression), and treatment group (depression + gentiopicroside). Corticosterone was administrated to induce depression-like model rats. Morris water maze test was used to validated the behavior performance. The hippocampus of rats was obtained for metabolomic detection. Metabolites that were differentially expressed between the groups were extracted for Heatmap, Go, and pathway enrichment analyses. Finally, neuronal cells were cultured and examined to validated the effect of gentiopicroside.

RESULTS

Corticosterone injured rats learning capacity, and decreased the levels of 5-HT, and reversed by gentiopicroside delivery. Metabolites obtained from the hippocampus of rats in the three groups were subjected to a principal component analysis (PCA). Go and pathway enrichment analyses revealed the involvement of sphingolipid metabolism et al. Gentiopicroside could inhibit apoptosis caused by corticosterone, and also decrease neuronal cell proliferation and BDNF levels in vitro. Arachidonic acid (ARA) reversed the protective effect of gentiopicroside on neuronal cells.

CONCLUSION

These findings suggest that gentiopicroside reduces apoptosis and increases the proliferation of hippocampus cells in depressed animals by regulating metabolites. Moreover, our study provides a new basis for the clinical treatment of depression and demonstrates the potential efficacy of gentiopicroside in this area of pathology.

Epigenetic variation at the SLC6A4 gene promoter in mother-child pairs with major depressive disorder

BACKGROUND

Genetic and epigenetic variations of the serotonin transporter gene (SLC6A4) have been related to the etiology of depression. The 5-HTTLPR polymorphism at the SLC6A4 promoter region has two variants, a short allele (S) and a long allele (L), in which the S allele results in lower gene transcription and has been associated with depression. The short S-allele of 5-HTTLPR polymorphism of this gene has been associated with depression. In addition to molecular mechanisms, exposure to early life risk factors such as maternal depression seems to affect the development of depression in postnatal life. The present study investigated the association of 5-HTTLPR polymorphism and CpG DNA methylation (5mC) levels of an AluJb repeat element at the SLC6A4 promoter region in mother-child pairs exposed to maternal depression.

METHODS

We analyzed DNA samples from 60 subjects (30 mother-child pairs) split into three groups, with and without major depression disorder (DSM-IV) among children and mothers. The genotyping of 5-HTTLPR polymorphism and quantification of 5mC levels was performed by qualitative PCR and methylation-sensitive restriction enzyme digestion, and real-time quantitative PCR (MSRED-qPCR), respectively.

RESULTS

The sample analyzed presented a higher frequency of S allele of 5-HTTLPR (67.5%). Despite the high frequency of this allele, we did not find statistically significant differences between individuals carrying at least one S allele between the depression and healthy control subjects, or among the mother-child pair groups with different patterns of occurrence of depression. In the group where the mother and child were both diagnosed with depression, we found a statistically significant decrease of the 5mC level at the SLC6A4 promoter region.

LIMITATIONS

The limitations are the relatively small sample size and lack of gene expression data available for comparison with methylation data.

CONCLUSION

In this study, we demonstrated a repeat element specific 5mC level reduction in mother-child pairs, concordant for the diagnosis of depression.

The serotonin transporter promoter polymorphism moderates the continuity of behavioral inhibition in early childhood

Persistently elevated behavioral inhibition (BI) in children is a marker of vulnerability to psychopathology. However, little research has considered the joint influences of caregiver and child factors that may moderate the continuity of BI in early childhood, particularly genetic variants that may serve as markers of biological plasticity, such as the serotonin transporter linked polymorphic region (5-HTTLPR). We explored this issue in 371 preschoolers and their caregivers, examining whether parent characteristics (i.e., overinvolvement or anxiety disorder) and child 5-HTTLPR influenced the continuity of BI between ages 3 and 5. Measures were observational ratings of child BI, observational and questionnaire measures of parenting, and parent interviews for anxiety disorder history, and children were genotyped for the 5-HTTLPR. Parent factors did not moderate the association between age 3 and age 5 BI; however, child BI at age 3 interacted with children's 5-HTTLPR variants to predict age 5 BI, such that children with at least one copy of the short allele exhibited less continuity of BI over time relative to children without this putative plasticity variant. Findings are consistent with previous work indicating the 5-HTTLPR short variant increases plasticity to contextual influences, thereby serving to decrease the continuity of BI in early childhood.

Cortisol reactivity to stress among youth: stability over time and genetic variants for stress sensitivity

Stress sensitivity may be one process that can explain why some genetically at-risk individuals are more susceptible to some types of stress-reactive psychopathologies. Dysregulation of the limbic-hypothalamic-pituitary-adrenal (LHPA) axis, including cortisol reactivity to challenge, represents a key aspect of stress sensitivity. However, the degree of stability over time among youth, especially differential stability as a function of particular genetic variants, has not been investigated. A general community sample of children and adolescents (mean age = 11.4; 56% girls) provided a DNA sample and completed 2 separate laboratory stress challenges, across an 18-month follow-up (N = 224 at Time 1; N = 194 at Time 2), with repeated measures of salivary cortisol. Results showed that test-retest stability for several indices of cortisol reactivity across the laboratory challenge visits were significant and of moderate magnitude for the whole sample. Moreover, gene variants of several biologically plausible systems relevant for stress sensitivity (especially 5-HTTLPR and CRHR1) demonstrated differential stability of cortisol reactivity over 18-months, such that carriers of genotypes conferring enhanced environmental susceptibility exhibited greater stability of cortisol levels over time for some LHPA axis indices. Findings suggest that LHPA axis dysregulation may exhibit some trait-like aspects underlying stress sensitivity in youth, especially for those who carry genes related to greater genetic susceptibility to environmental stress.

The Involvement of Genes in Adolescent Depression: A Systematic Review

Numerous studies have reported on the roles of genetic factors in the development of depression in adolescents and young adults. However, there are few systematic reviews that update our understanding of adolescent depression with the biological findings identifying the roles of gene expression and/or polymorphism(s). This review systematically summarized the findings that clearly identified the contribution of a gene to the risk of depression in adolescents between the ages of 10 and 19 years old and young adults between the ages of 20 and 25 years old. Data were obtained through searching PubMed, Embase, and Web of Science. A total of 47 studies on early adolescence and three studies on young adults were included in the current review. Most articles studied genes in the serotonergic system (n = 26), dopaminergic system (n = 3), and the Brain-derived neurotropic factor (BDNF) gene (n = 12). 92.3% of studies (24/26) identified positive associations of 5-HTTLPR polymorphism with depressive illness or depressive symptoms. 83.3% of studies (10/12) found positive association between BDNF Val66Met genotype and adolescent depressive symptoms. More studies should be conducted on the 18 genes reported in a few studies to clarify their roles in the risk for adolescent depression.

Depression from childhood into late adolescence: Influence of gender, development, genetic susceptibility, and peer stress

Depression is a debilitating mental illness with clear developmental patterns from childhood through late adolescence. Here, we present data from the Gene Environment Mood (GEM) study, which used an accelerated longitudinal cohort design with youth (N = 665) starting in 3rd, 6th, and 9th grades, and a caretaker, who were recruited from the general community, and were then assessed repeatedly through semistructured diagnostic interviews every 6 months over 3 years (7 waves of data) to establish and then predict trajectories of depression from age 8 to 18. First, we demonstrated that overall prevalence rates of depression over time, by age, gender, and pubertal status, in the GEM study closely match those trajectories previously obtained in past developmental epidemiological research. Second, we tested whether a genetic vulnerability-stress model involving 5-HTTLPR and chronic peer stress was moderated by developmental factors. Results showed that older aged adolescents with SS/SL genotype, who experienced higher peer chronic stress over 3 years, were the most likely to be diagnosed with a depressive episode over time. Girls experiencing greater peer chronic stress were the most likely to develop depression. This study used repeated assessments of diagnostic interviewing in a moderately large sample of youth over 3 years to show that depression rates increase in middle to late adolescence, or postpubertally, and that the gender difference in depression emerges earlier in adolescence (age 12.5), or postpubertally. Additionally, genetically susceptible older adolescents who experience chronic peer stress were the most likely to become depressed over time.

Maternal Depression Trajectories and Children's Behavior at Age 5 Years

OBJECTIVE

To assess the relationship between trajectories of maternal depression from pregnancy to the child's age of 5 years and children's emotional and behavioral difficulties at age 5 years.

STUDY DESIGN

Mother-child pairs (n = 1183) from the EDEN mother-child birth cohort study based in France were followed from 24 to 28 weeks of pregnancy to the child's fifth birthday. Children's behavior at age 5 years was assessed with the Strengths and Difficulties Questionnaire. Maternal depression was assessed repeatedly with the Center for Epidemiological Studies Depression questionnaire (pregnancy, 3, and 5 years of age) and the Edinburgh Postnatal Depression Scale (4, 8, and 12 months postpartum). Homogeneous latent trajectory groups of maternal depression were identified within the study population and correlated with Strengths and Difficulties Questionnaire scores by the use of multivariate linear regression analyzes.

RESULTS

Five trajectories of maternal symptoms of depression were identified: no symptoms (62.0%); persistent intermediate-level depressive symptoms (25.3%); persistent high depressive symptoms (4.6%); high symptoms in pregnancy only (3.6%); and high symptoms in the child's preschool period only (4.6%). Children whose mothers had persistent depressive symptoms--either intermediate or high--had the greatest levels of emotional and behavioral difficulties at age 5 years. In addition, compared with children whose mothers were never depressed, those whose mothers had high symptoms in the preschool period also had increased levels of emotional symptoms, conduct problems, and peer problems.

CONCLUSIONS

Maternal depression symptoms are related to children's emotional and behavioral problems, particularly if they are persistent (29.9%) or occur during early childhood (4.6%).

5-HTTLPR × interpersonal stress interaction and nonsuicidal self-injury in general community sample of youth

No research with youth has investigated whether measured genetic risk interacts with stressful environment (G⁎E) to explain engagement in non-suicidal self-injury (NSSI). Two independent samples of youth were used to test the a priori hypothesis that the Transporter-Linked Polymorphic Region (5-HTTLPR) would interact with chronic interpersonal stress to predict NSSI. We tested this hypothesis with children and adolescents from United States public schools in two independent samples (N׳s=300 and 271) using identical procedures and methods. They were interviewed in person with the Self-Injurious Thoughts and Behaviors Interview to assess NSSI engagement and with the UCLA Chronic Stress Interview to assess interpersonal stress. Buccal cells were collected for genotyping of 5-HTTLPR. For both samples, ANOVAs revealed the hypothesized G*E. Specifically, short carriers who experienced severe interpersonal stress exhibited the highest level of NSSI engagement. Replicated across two independent samples, results provide the first demonstration that youth at high genetic susceptibility (5-HTTLPR) and high environmental exposure (chronic interpersonal stress) are at heightened risk for NSSI.

Oxytocin receptor gene polymorphism (rs53576) moderates the intergenerational transmission of depression

Maternal depression serves as a potent source of stress among offspring, greatly enhancing the risk of numerous adverse outcomes including youth depression. Several factors moderate the transmission of depression from mothers to offspring. However, the role of genetic characteristics in this process merits further exploration. Consistent with an interpersonal perspective on depression, the present study focused on a genetic polymorphism that has been shown to be relevant to social functioning, the rs53576 polymorphism of the oxytocin receptor gene (OXTR). In a community sample of 441 youth, OXTR genotype moderated the association between maternal depression in early childhood and youth depressive symptoms in adolescence, such that youth possessing at least one A allele of OXTR who also had a history of maternal depression exhibited the highest levels of depressive symptoms at age 15. In order to explore possible interpersonal mediators of this effect, conditional process analyses examined the role of youth social functioning in adolescence. Results suggest that OXTR genotype may partially account for the transmission of maternal depression to youth and support the role of dysfunctional social processes as a mechanism through which OXTR influences the development of depressive symptoms.