The predictive capacity of psychiatric and psychological polygenic risk scores for distinguishing cases in a child and adolescent psychiatric sample from controls

Research Review: A review of the past decade of family and genomic studies on adolescent mental health

BACKGROUND

Mental health problems and traits capturing psychopathology are common and often begin during adolescence. Decades of twin studies indicate that genetic factors explain around 50% of individual differences in adolescent psychopathology. In recent years, significant advances, particularly in genomics, have moved this work towards more translational findings.

METHODS

This review provides an overview of the past decade of genetically sensitive studies on adolescent development, covering both family and genomic studies in adolescents aged 10-24 years. We focus on five research themes: (1) co-occurrence or comorbidity between psychopathologies, (2) stability and change over time, (3) intergenerational transmission, (4) gene-environment interplay, and (5) psychological treatment outcomes.

RESULTS

First, research shows that much of the co-occurrence of psychopathologies in adolescence is explained by genetic factors, with widespread pleiotropic influences on many traits. Second, stability in psychopathology across adolescence is largely explained by persistent genetic influences, whereas change is explained by emerging genetic and environmental influences. Third, contemporary twin-family studies suggest that different co-occurring genetic and environmental mechanisms may account for the intergenerational transmission of psychopathology, with some differences across psychopathologies. Fourth, genetic influences on adolescent psychopathology are correlated with a wide range of environmental exposures. However, the extent to which genetic factors interact with the environment remains unclear, as findings from both twin and genomic studies are inconsistent. Finally, a few studies suggest that genetic factors may play a role in psychological treatment response, but these findings have not yet been replicated.

CONCLUSIONS

Genetically sensitive research on adolescent psychopathology has progressed significantly in the past decade, with family and twin findings starting to be replicated at the genomic level. However, important gaps remain in the literature, and we conclude by providing suggestions of research questions that still need to be addressed.

Associations between polygenic risk score and covid-19 susceptibility and severity across ethnic groups: UK Biobank analysis

BACKGROUND

COVID-19 manifests with huge heterogeneity in susceptibility and severity outcomes. UK Black Asian and Minority Ethnic (BAME) groups have demonstrated disproportionate burdens. Some variability remains unexplained, suggesting potential genetic contribution. Polygenic Risk Scores (PRS) can determine genetic predisposition to disease based on Single Nucleotide Polymorphisms (SNPs) within the genome. COVID-19 PRS analyses within non-European samples are extremely limited. We applied a multi-ethnic PRS to a UK-based cohort to understand genetic contribution to COVID-19 variability.

METHODS

We constructed two PRS for susceptibility and severity outcomes based on leading risk-variants from the COVID-19 Host Genetics Initiative. Scores were applied to 447,382 participants from the UK-Biobank. Associations with COVID-19 outcomes were assessed using binary logistic regression and discriminative power was validated using incremental area under receiver operating curve (ΔAUC). Variance explained was compared between ethnic groups via incremental pseudo-R2 (ΔR2).

RESULTS

Compared to those at low genetic risk, those at high risk had a significantly greater risk of severe COVID-19 for White (odds ratio [OR] 1.57, 95% confidence interval [CI] 1.42-1.74), Asian (OR 2.88, 95% CI 1.63-5.09) and Black (OR 1.98, 95% CI 1.11-3.53) ethnic groups. Severity PRS performed best within Asian (ΔAUC 0.9%, ΔR2 0.98%) and Black (ΔAUC 0.6%, ΔR2 0.61%) cohorts. For susceptibility, higher genetic risk was significantly associated with COVID-19 infection risk for the White cohort (OR 1.31, 95% CI 1.26-1.36), but not for Black or Asian groups.

CONCLUSIONS

Significant associations between PRS and COVID-19 outcomes were elicited, establishing a genetic basis for variability in COVID-19. PRS showed utility in identifying high-risk individuals. The multi-ethnic approach allowed applicability of PRS to diverse populations, with the severity model performing well within Black and Asian cohorts. Further studies with larger sample sizes of non-White samples are required to increase statistical power and better assess impacts within BAME populations.

Polygenic risk for neuroticism is associated with externalizing symptoms in 2-year-old boys

Recent advances in genome-wide association studies have enabled the estimation of genetic risk of complex traits, including neuroticism, with polygenic risk scores (PRS). Neuroticism PRS has been associated with psychiatric disorders and symptoms in adults, but studies in children are scarce. We studied whether neuroticism PRS, and its subscales, worry PRS and depressive affect PRS, were associated with externalizing and internalizing symptoms in 2-year-olds. We also examined parental neuroticism PRSs' association with children's externalizing and internalizing symptoms and whether parental depressive symptoms mediated the effect. Participants from two Finnish birth cohorts, CHILD-SLEEP and FinnBrain Birth Cohort Study, who had DNA and data on Brief Infant-Toddler Social and Emotional Assessment (BITSEA) available were included in the study (N = 806 and N = 987, respectively). PRSs were calculated based on GWAS data from UK Biobank. Child's neuroticism PRS, and its subscale worry PRS, were positively associated with externalizing symptoms in 2-year-old boys, but not in girls. Mother's depressive symptoms mediated the association between maternal neuroticism PRS and externalizing and internalizing symptoms in boys, but not in girls. Our results suggest that neuroticism PRS, and its subscale worry PRS, are associated with externalizing symptoms in already as young as 2-year-old boys, and, that subclinical symptoms of maternal depression that are based on genetic disposition, have an effect on boy's internalizing and externalizing symptoms. As we did not find any associations in girls, our study supports the suggestion that girls and boys may differ in how genetic and environmental factors contribute to their development.

Genetic risk of AUDs and childhood impulsivity: Examining the role of parenting and family environment

This study examined the independent and interactive effects of genetic risk for alcohol use disorder (AUD), parenting behaviors, and family environment on childhood impulsivity. Data were drawn from White (n = 5,991), Black/African American (n = 1,693), and Hispanic/Latino (n = 2,118) youth who completed the baseline assessment (age 9-10) and had genotypic data available from the Adolescent Brain Cognitive Development Study. Participants completed questionnaires and provided saliva or blood samples for genotyping. Results indicated no significant main effects of AUD genome-wide polygenic scores (AUD-PRS) on childhood impulsivity as measured by the UPPS-P scale across racial/ethnic groups. In general, parental monitoring and parental acceptance were associated with lower impulsivity; family conflict was associated with higher impulsivity. There was an interaction effect between AUD-PRS and family conflict, such that family conflict exacerbated the association between AUD-PRS and positive urgency, only among Black/African American youth. This was the only significant interaction effect detected from a total of 45 tests (five impulsivity dimensions, three subsamples, and three family factors), and thus may be a false positive and needs to be replicated. These findings highlight the important role of parenting behaviors and family conflict in relation to impulsivity among children.

1H-NMR-Based Metabolomics in Autism Spectrum Disorder and Pediatric Acute-Onset Neuropsychiatric Syndrome

We recently described a unique plasma metabolite profile in subjects with pediatric acute-onset neuropsychiatric syndrome (PANS), suggesting pathogenic models involving specific patterns of neurotransmission, neuroinflammation, and oxidative stress. Here, we extend the analysis to a group of patients with autism spectrum disorder (ASD), as a consensus has recently emerged around its immune-mediated pathophysiology with a widespread involvement of brain networks. This observational case-control study enrolled patients referred for PANS and ASD from June 2019 to May 2020, as well as neurotypical age and gender-matched control subjects. Thirty-four PANS outpatients, fifteen ASD outpatients, and twenty-five neurotypical subjects underwent physical and neuropsychiatric evaluations, alongside serum metabolomic analysis with 1H-NMR. In supervised models, the metabolomic profile of ASD was significantly different from controls (p = 0.0001), with skewed concentrations of asparagine, aspartate, betaine, glycine, lactate, glucose, and pyruvate. Metabolomic separation was also observed between PANS and ASD subjects (p = 0.02), with differences in the concentrations of arginine, aspartate, betaine, choline, creatine phosphate, glycine, pyruvate, and tryptophan. We confirmed a unique serum metabolomic profile of PANS compared with both ASD and neurotypical subjects, distinguishing PANS as a pathophysiological entity per se. Tryptophan and glycine appear as neuroinflammatory fingerprints of PANS and ASD, respectively. In particular, a reduction in glycine would primarily affect NMDA-R excitatory tone, overall impairing downstream glutamatergic, dopaminergic, and GABAergic transmissions. Nonetheless, we found metabolomic similarities between PANS and ASD that suggest a putative role of N-methyl-D-aspartate receptor (NMDA-R) dysfunction in both disorders. Metabolomics-based approaches could contribute to the identification of novel ASD and PANS biomarkers.

The Role of Antenatal and Postnatal Maternal Bonding in Infant Development

OBJECTIVE

The affectional bond experienced by a mother toward her developing fetus/infant has been theorized to be a critical factor in determining infant developmental outcomes; yet there remains a paucity of research in this area, and a lack of high-quality longitudinal studies. This study aimed to examine the extent to which mother-to-infant bonding predicted infant development in a multi-wave longitudinal pregnancy cohort study (N = 1,347).

METHOD

Self-reported bonding was assessed using the Maternal Antenatal Attachment Scale at each trimester, and the Maternal Postnatal Attachment Scale at 8 weeks and 12 months postpartum. Infant development was assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) at 12 months.

RESULTS

Bonding predicted indicators of infant social-affective development, including social-emotional, behavioral, and temperamental outcomes. Effect sizes ranged from small to moderate, increasing over the perinatal period (β = 0.11-0.27). Very small effects were also identified in the relationship between bonding and cognitive, language, and motor development (β = 0.06-0.08).

CONCLUSION

Findings suggest that a mother's perceived emotional connection with her child plays a role in predicting social-affective outcomes; prediction may not extend to other domains of infant development. Maternal bonding may therefore be a potentially modifiable predictor of infant social-affective outcomes, offering important considerations for preventive intervention.