“…For example, while it is well established that depression and anxiety are among the most frequent psychiatric disorders associated with ASD (Bakken et al, 2010; Helverschou et al, 2011; Hollocks et al, 2018; Moss, Howlin, Savage, Bolton, & Rutter, 2015; Lugo‐Marin et al, 2019; Simonoff et al, 2012; Skokauskas & Gallagher, 2010; Steensel, Bögels, & Perrin, 2011) most data on mental health problems are derived from cohorts of individuals with ASD without co‐occurring ID (Hollocks et al, 2018; Lugo‐Marin et al, 2019; Matson & Cervantes, 2014). Furthermore, there is no consensus about how to adapt standard diagnostic criteria for identifying mental illness in people with ASD and ID, and few specialist diagnostic instruments are available (Helverschou, Kildahl, & Bakken, 2020; Lugo‐Marin et al, 2019; Underwood, McCarthy, & Tsakanikos, 2011).…”