“…These characteristics include habitual overuse which may render it problematic (Kwon et al, 2013; van Deursen, Bolle, Hegner, & Kommers, 2015); functional impairment including impaired driving (Violanti, 1998), difficulties in real-life social engagement (Kuss & Griffiths, 2011), sleep difficulties, depression, and anxiety (Demirci et al, 2015; Elhai et al, 2017); withdrawal following cessation of use (Kwon et al, 2013) such as elevated heart rate (Clayton, Leshner, & Almond, 2015); and a reinforcement element embedded in smartphone use such as pleasurable experiences (Kwon et al, 2013; Song, Larose, Eastin, & Lin, 2004). This conceptualization of PSU is similar to the defining features of other addictive behaviors such as substance use (Fisher, Elias, & Ritz, 1998; Marlatt, Baer, Donovan, & Kivlahan, 1988; Shaffer, 1996), hence we draw from relevant PTSD-addictive behaviors literature as elaborated below.…”