Emotion Reactivity and Regulation in Autistic Adults: A Systematic Review Across <scp>RDoC</scp> Units of Analysis

Emotion reactivity and regulation are implicated in the experience of anxiety and depression by autistic adults, but their measurement has been hindered by reliance on subjective judgment. Biological measurement methods may improve insight by offering a perspective beyond self/other-report. Using PRISMA guidelines, this systematic review aimed to (1) clarify current emotion reactivity and regulation measurement practices used with autistic adults, and (2) summarize conclusions on the autistic adult experience, organized across Research Domain Criteria (RDoC) units of analysis (circuits, physiology, behavior, self-/caregiver-report). Of the 31 original peer-reviewed studies that met inclusion criteria, there were 41 different reports: 15 circuitry, 13 physiological, one behavioral, and 14 self-/caregiver-reports of emotion reactivity and/or regulation. Findings generally indicated reduced emotion reactivity and emotion regulation processes for autistic adults compared to non-autistic groups, but inconsistencies emerged depending upon the emotional paradigms, social stimuli, laboratory versus naturalistic setting, sample characteristics, or RDoC measurement tools used. Overall, study design heterogeneity has limited the ability to infer how emotion reactivity and regulation are measured and, therefore, impacted in autistic adults. Future studies should establish standard methods across multiple measurements, assess both positive and negative emotions, and include diverse racial/cultural backgrounds and ability levels. In conclusion, there remains a dearth of evidence using circuitry, physiological, and behavioral measures of emotion reactivity and regulation in autistic adults, thus limiting our understanding of these critical internal experiences and processes.