... These interventions, grounded in principles of nonjudgmental awareness, acceptance, defusion, and self-compassion, aim to address an individual's relationship with, and response to, certain cognitive and affective processes, rather than directly trying to modify them or their content (Hayes, Villatte, Levin, & Hildebrandt, 2011;Hofmann & Asmundson, 2008). Importantly, several previous metaanalyses of randomized controlled trials (RCT) have documented the efficacy of acceptance-and mindfulness-based interventions delivered in either face-to-face or online formats for several mental health problems, including symptoms of depression (Hofmann, Sawyer, Witt, & Oh, 2010), anxiety (Vøllestad, Nielsen, & Nielsen, 2012), eating disorders (Linardon, Fairburn, Fitzsimmons-Craft, Wilfley, & Brennan, 2017;Linardon, Gleeson, Yap, Murphy, & Brennan, 2018), psychosis (Louise, Fitzpatrick, Strauss, Rossell, & Thomas, 2018), and general distress (Spijkerman, Pots, & Bohlmeijer, 2016). ...