“…This contrasts with the traditional categorical approach to conceptualizing NDDs in which each diagnosis is considered a discrete and separate entity, and intervention occurs when impairment exceeds diagnostic thresholds. A transdiagnostic, dimensional approach to developmental risk aligns with the National Institute of Mental Health Research Domain Criteria framework (Casey, Oliveri, & Insel, ), and is supported by findings of high prevalence of co‐occurrence between NDDs (Weyrauch, Schwartz, Hart, Klug, & Burd, ); overlap among core symptoms of NDDs (Craig et al., ; Dajani, Llabre, Nebel, Mostofsky, & Uddin, ); and marked heterogeneity in behavioral presentation within diagnostic groups, including within monogenic disorders (e.g., Dajani et al., ). This transdiagnostic or cross‐syndrome approach to identifying NDDs lends itself to a model for early intervention in which intervention is targeted at a specific phenotype or a hypothesized shared underlying mechanism, rather than at a diagnostic group.…”