A study was conducted to evaluate and catalog response biomarkers linked to autism spectrum disorder (ASD) symptoms. The goal of the study was to help improve clinical trials.

In April 2020, a methodical review of MEDLINE, Embase, and Scopus was conducted. The focus was on original research on quantitative response biomarkers tested alongside ASD symptoms. The research was done using seven criteria. Included were interventional studies or human studies that examined the relationship between biomarkers and behavioral assessments associated with ASD.

A total of 280 articles reporting on 940 biomarkers, 755 of which were exclusive to one publication, were found in 5,799 independent records. In addition to cytokines, growth factors, indicators of oxidative stress, neurotransmitters, and hormones, neurophysiology (such as EEG and eye tracking), neuroimaging (such as functional MRI), and other physiological measurements were also often used as molecular biomarkers. Studies were very diverse in terms of phenotypes, demographics, tissues analyzed, and techniques for finding biomarkers. Nearly all of the studies that were assessed, with a median total sample size of 64, were only powered to find biomarkers with substantial effect sizes. Mega- and meta-analyses were made more difficult by the uneven reporting of individual-level values and summary statistics. A “replication crisis” was revealed as the biomarkers assayed in multiple studies showed inconsistent results.

There is presently no response biomarker supported by adequate data to guide clinical trials for ASD. This review identified key methodological requirements for ASD biomarker research that must be met in order to make significant advancements. These requirements include consistent experimental design, multiple comparison correction, formal replication, sharing of sample-level data, and preregistration of study designs. In addition, multiple possible biomarkers could be subjected to systematic “big data” analyses to speed up discovery.

Reference: ajp.psychiatryonline.org/doi/10.1176/appi.ajp.21100992