Lack of univariate, clinically-relevant biomarkers of autism in resting state EEG: a study of 776 participants

Mental health conditions are difficult to diagnose, requiring expert clinicians and subjective judgements. There has been interest in finding quantitative biomarkers using resting state electroencephalogram (EEG) data. Here, we focus on resting state EEG biomarkers of autism. Although many previous reports have pointed to differences between autistic and neurotypical participants, results have often failed to replicate and sample sizes have typically been small. Taking a big-data, open-science approach, we combined data from 5 studies to create a large sample of autistic and neurotypical individuals (n=776) and used high-power computing to extract 942 variables from each participant's data. Using a systematic, preregistered analysis pipeline, we failed to identify even a single EEG-based variable that could serve as a practically useful biomarker of autism clinical diagnosis. Our results highlight that a biomarker for autism drawn from EEG data is an elusive construct that may not exist. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: National Institute of Mental Health Data Archive (NDA) data repository 10.15154/1528473 was used for this study. This repository was created by the first author using the NDA data selection tool. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All EEG variables extracted from the raw data are available at the individual participant level at https://github.com/adede1988/SheffieldAutismBiomarkers.git. All raw data are available on the National Insitute of Mental Health Data Archive website in repository 10.15154/1528473.