This work was funded by the Economic and Social Research Council (grant no. ES/P000592/1 to A. Hollowell) and the Simons Foundation for Autism Research Initiative (grant no. 724306 to A.R.). L.J.H. was supported by grants from the South-Eastern Norway Regional Health Authority (Helse Sor-& Oslash;st; nos 2022083 and 2019097). E.C.C. was supported by grants from Helse Sor-& Oslash;st (no. 2021045) and the Research Council of Norway (no. 274611). E.C.C. is a member of the MRC Integrative Epidemiology Unit at the University of Bristol, which is supported by the Medical Research Council and the University of Bristol (MC_UU_00032/1). S.B. was supported by the Consortium on Individual Differences, funded by the Netherlands Organization for Scientific Research (NWO) Gravitation programme (grant no. 0240-001-003). B.S.P. is supported by the Max Planck Society and the R2D2-MH project, which has been funded by Horizon Europe (grant no. 101057385), and by UK Research and Innovation under the UK government's Horizon Europe funding guarantee (grant no. 10039383) and by the Swiss State Secretariat for Education, Research and Innovation (contract no. 22.00277). M.B. is supported by an NWO VICI grant (no. VI.C.211.054). D.I.B. acknowledges the Royal Netherlands Academy of Arts and Science Professor Award (no. PAH/6635). M.T.L. was supported by the Harry Crossley Clinical Research Fellowship. D.J.S. and H.J.Z. were supported by the South African Medical Research Council. The Autism Spectrum Disorder Working Group of the Psychiatric Genomics Consortium was supported by the National Institute for Mental Health (NIMH) (NIH/NIMH grant no. 1R01MH124851-01). X.Z. and V.W. were supported by the Simons Foundation for Autism Research Initiative, the Wellcome Trust (grant nos 214322/Z/18/Z and 226392/Z/22/Z), Horizon-Europe R2D2-MH (grant agreement no. 101057385) and UK Research and Innovation (grant no. 10063472). T.A. was supported by the following grants: MRC Senior Clinical Fellowship (no. MR/Y009665/1) and MRC Centre for Neurodevelopmental Disorders (no. MR/N026063/1). M.H.J. was supported by the UK Medical Research Council (grant nos G0701484, MR/K021389/1 and MR/T003057/1). S.J.S. was supported by the NIMH (grant nos R01MH129751 and U01MH122681) and the HDR UK QQ2 Molecules to Health Records Driver Programme. A. Havdahl was supported by the Research Council of Norway (grant no. 336085), Helse Sor-& Oslash;st (grant no. 2020022) and the European Union's Horizon Europe Research and Innovation programme (FAMILY no. 101057529). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. This is a summary of independent research carried out at the National Institute for Health and Care Research Leicester Biomedical Research Centre. The views expressed are those of the authors and not necessarily those of the National Institute for Health and Care Research or the Department of Health and Social Care. For the purpose of open access, the authors have applied a Creative Commons attribution licence (CC BY) to any Author Accepted Manuscript version arising from this submission. The iPSYCH team was supported by grants from the Lundbeck Foundation (R102-A9118, R155-2014-1724, and R248-2017-2003), NIH/NIMH (1R01MH124851-01 to A.D.B.), EU's Horizon Europe program under grant agreement no. 101057385 (R2D2-MH; to A.D.B.) and the Universities and University Hospitals of Aarhus and Copenhagen. High-performance computer capacity for handling and statistical analysis of iPSYCH data on the GenomeDK HPC facility was provided by the Center for Genomics and Personalized Medicine and the Centre for Integrative Sequencing, iSEQ, Aarhus University, Denmark (grant to A.D.B.). MoBa is supported by the Norwegian Ministry of Health and Care Services and the Ministry of Education and Research. We are grateful to all the participating families in Norway who take part in this ongoing cohort study. For generating high-quality genomic data, we thank the Norwegian Institute of Public Health, the HARVEST collaboration, the NORMENT Centre at the University of Oslo, the Center for Diabetes Research at the University of Bergen, deCODE Genetics, the Research Council of Norway, the South-Eastern and Western Norway Regional Health Authorities, the ERC AdG, Stiftelsen KG Jebsen, the Trond Mohn Foundation and the Novo Nordisk Foundation. This work was performed on the Tjeneste for Sensitive Data facilities, owned by the University of Oslo, operated and developed by the Tjeneste for Sensitive Data service group at the University of Oslo, IT-Department (tsd-drift@usit.uio.no). The computations were performed on resources provided by Sigma2-the National Infrastructure for High Performance Computing and Data Storage in Norway. We are extremely grateful to all the families who took part in this study, the midwives for their help in recruiting them and the whole ALSPAC team, which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists and nurses. Genome-wide genotyping data were generated by Sample Logistics and Genotyping Facilities at Wellcome Sanger Institute and LabCorp (Laboratory Corporation of America) using support from 23andMe. The UK Medical Research Council and Wellcome (grant no. 217065/Z/19/Z) and the University of Bristol provide core support for ALSPAC. This publication is the work of the authors, and A. Hollowell and A.R. will serve as guarantors for the contents of this paper. The Lifelines initiative has been made possible by subsidies from the Dutch Ministry of Health, Welfare and Sport; the Dutch Ministry of Economic Affairs; the University Medical Center Groningen; Groningen University; and the Provinces in the North of the Netherlands (Drenthe, Friesland and Groningen). The authors wish to acknowledge the services of the Lifelines Cohort Study, the contributing research centres delivering data to Lifelines and all the study participants. NTR acknowledges funding from the NWO, including NWO-Grants NWO/SPI 56-464-14192 and 480-15-001/674: Netherlands Twin Registry Repository and the Biobanking and Biomolecular Resources Research Infrastructure (grant nos 184.021.007 and 184.033.111); Amsterdam Public Health and Neuroscience Campus Amsterdam; the European Community 7th Framework Program (FP7/2007-2013): ENGAGE (grant no. HEALTH-F4-2007-201413) and ACTION (grant no. 9602768); and the European Research Council (grant no. ERC-230374). We also acknowledge the Rutgers University Cell and DNA Repository cooperative agreement (NIMH U24 MH068457-06); the Collaborative Study of the Genetics of DZ Twinning (NIH R01D0042157-01A1); the Developmental Study of Attention Problems in Young Twins (NIMH, RO1 MH58799-03); Major Depression: Stage 1 Genome-Wide Association in Population-Based Samples (MH081802); Determinants of Adolescent Exercise Behavior (NIDDK R01 DK092127-04); Grand Opportunity grants Integration of Genomics and Transcriptomics (NIMH 1RC2MH089951-01) and Developmental Trajectories of Psychopathology (NIMH 1RC2 MH089995); and the Avera Institute for Human Genetics, Sioux Falls, South Dakota (USA). We also thank the participants and parents for their voluntary participation in the research project of NTR. TEDS is supported by the UK Medical Research Council (grant nos MR/V012878/1 and previously MR/M021475/1). We gratefully acknowledge the ongoing contribution of the participants in TEDS and their families. TEDS was granted ethical approval by the Kings College London Ethics Committee (HR/DP-20/21-22060). Consent was obtained from participants for every wave of data collection. The TMM BirThree Cohort Study was supported by the Japan Agency for Medical Research and Development (AMED), Japan (grant nos JP17km0105001 and JP21tm0124005). This study used a supercomputer system provided by the Tohoku Medical Megabank Project, funded by AMED (grant no. JP21tm0424601). We are sincerely grateful to the people of Japan and of the world for providing their valuable support to the individuals and areas affected by the Great East Japan Earthquake disaster. We thank the members of Tohoku Medical Megabank Organization, including the genome medical research coordinators, office and administrative personnel and software engineers, for their assistance with the projects. The full lists of members are available at https://www.megabank.tohoku.ac.jp/english/a250901/ for the Tohoku Medical Megabank Organization. We thank the mothers and their children in the South African Drakenstein Child Health study (DCHS) and the study staff, as well as the clinical and administrative staff of the Western Cape Government Health Department at Paarl Hospital and at the clinics for support of the study. The DCHS study is funded by the Gates Foundation (grant nos. OPP1017641 and OPP1017579), NIH and the Wellcome Trust (221372/Z/20/Z).