@article {367, title = {Developmental co-occurrence of psychopathology dimensions in childhood}, journal = {JCPP Advances}, volume = {2}, year = {2022}, pages = {e12100}, abstract = {

Background: Comorbidity between psychopathologies may be attributed to genetic and environmental differences between people as well as causal processes within individuals, where one pathology increases risk for another. Disentangling between-person (co)variance from within-person processes of psychopathology dimensions across childhood may shed light on developmental causes of comorbid mental health problems. Here, we aim to determine whether and to what extent directional relationships between psychopathology dimensions within-person, and between individuals within families, play a role in comorbidity. Methods: We conducted random intercepts cross-lagged panel model (RI-CLPM) analyses to unravel the longitudinal co-occurrence of child psychopathology dimensions, jointly estimating between-person and within-person processes from childhood to early adolescence (age 7-12). We further developed an extension of the model to estimate sibling effects within-family (wf-RI-CLPM). Analyses were separately conducted in two large population-based cohorts, TEDS and NTR, including parent-rated measures of child problem behaviours based on the SDQ and CBCL scales respectively. Results: We found evidence for strong between-person effects underlying the positive intercorrelation between problem behaviours across time. Beyond these time-varying within-person processes accounted for an increasing amount of trait variance, within- and cross-trait, overtime in both cohorts. Lastly, by accommodating family level data, we found evidence for reciprocal directional influences within sib-pairs longitudinally. Conclusions: Our results indicate that within-person processes partly explain the co-occurrence of psychopathology dimensions across childhood, and within sib-pairs. Analyses provided substantive results on developmental processes underlying comorbidity in behavioural problems. Future studies should consider different developmental timeframes to shed more light on the processes contributing to developmental comorbidity.

}, keywords = {comorbidity, development, genetic and environmental effects, psychopathology, sibling effects}, doi = {10.1002/jcv2.12100}, author = {Allegrini, Andrea G and van Beijsterveldt, Toos and Boomsma, Dorret I and Rimfeld, Kaili and Pingault, Jean-Baptiste and Plomin, Robert and Bartels, Meike and Nivard, Michel G} } @article {259, title = {Differences in exam performance between pupils attending selective and non-selective schools mirror the genetic differences between them}, volume = {3}, year = {2018}, month = {2018/03/23}, pages = {3}, abstract = {

On average, students attending selective schools outperform their non-selective counterparts in national exams. These differences are often attributed to value added by the school, as well as factors schools use to select pupils, including ability, achievement and, in cases where schools charge tuition fees or are located in affluent areas, socioeconomic status. However, the possible role of DNA differences between students of different schools types has not yet been considered. We used a UK-representative sample of 4814 genotyped students to investigate exam performance at age 16 and genetic differences between students in three school types: state-funded, non-selective schools (\‘non-selective\’), state-funded, selective schools (\‘grammar\’) and private schools, which are selective (\‘private\’). We created a genome-wide polygenic score (GPS) derived from a genome-wide association study of years of education (EduYears). We found substantial mean genetic differences between students of different school types: students in non-selective schools had lower EduYears GPS compared to those in grammar (d\ =\ 0.41) and private schools (d\ =\ 0.37). Three times as many students in the top EduYears GPS decile went to a selective school compared to the bottom decile. These results were mirrored in the exam differences between school types. However, once we controlled for factors involved in pupil selection, there were no significant genetic differences between school types, and the variance in exam scores at age 16 explained by school type dropped from 7\% to \<1\%. These results show that genetic and exam differences between school types are primarily due to the heritable characteristics involved in pupil admission.

}, isbn = {2056-7936}, url = {https://doi.org/10.1038/s41539-018-0019-8}, author = {Emily Smith-Woolley and Pingault, Jean-Baptiste and Saskia Selzam and Kaili Rimfeld and Eva Krapohl and Sophie von Stumm and Asbury, Kathryn and Philip S. Dale and Young, Toby and Allen, Rebecca and Yulia Kovas and Robert Plomin} } @article {260, title = {Extracting stability increases the SNP heritability of emotional problems in young people}, volume = {8}, year = {2018}, month = {2018/10/17}, pages = {223}, abstract = {

Twin studies have shown that emotional problems (anxiety and depression) in childhood and adolescence are moderately heritable (~20\–50\%). In contrast, DNA-based \‘SNP heritability\’ estimates are generally \<15\% and non-significant. One notable feature of emotional problems is that they can be somewhat transient, but the moderate stability seen across time and across raters is predominantly influenced by stable genetic influences. This suggests that by capturing what is in common across time and across raters, we might be more likely to tap into any underlying genetic vulnerability. We therefore hypothesised that a phenotype capturing the pervasive stability of emotional problems would show higher heritability. We fitted single-factor latent trait models using 12 emotional problems measures across ages 7, 12 and 16, rated by parents, teachers and children themselves in the Twins Early Development Study sample. Twin and SNP heritability estimates for stable emotional problems (N\ =\ 6110 pairs and 6110 unrelated individuals, respectively) were compared to those for individual measures. Twin heritability increased from 45\% on average for individual measures to 76\% (se\ =\ 0.023) by focusing on stable trait variance. SNP heritability rose from 5\% on average (n.s.) to 14\% (se\ =\ 0.049; p\ =\ 0.002). Heritability was also higher for stable within-rater composites. Polygenic scores for both adult anxiety and depression significantly explained variance in stable emotional problems (0.4\%; p\ =\ 0.0001). The variance explained was more than in most individual measures. Stable emotional problems also showed significant genetic correlation with adult depression and anxiety (average\ =\ 52\%). These results demonstrate the value of examining stable emotional problems in gene-finding and prediction studies.

}, isbn = {2158-3188}, url = {https://doi.org/10.1038/s41398-018-0269-5}, author = {Cheesman, Rosa and Purves, Kirstin L. and Pingault, Jean-Baptiste and Breen, Gerome and Rijsdij k, Fruhling and Robert Plomin and Thalia C. Eley and Major Depressive Disorder Working Group of the Psychiatric Genomics Consortium} }