“…Reasons for this include issues such as lack of staff awareness, ability, or willingness or the lack of clinical resources where clinics are understaffed and staff are overburdened (Flynn & Brown, 2008;Levin et al, 2008). In addition, ADHD is characterized by impulsivity, restless, inattentive, and hyperactive behaviors-symptoms that often mimic those of substance use disorder (SUD; Barkley, 1998;Davidson, 2008;Levin et al, 2008). For these and other reasons, ADHD is frequently unidentified in adulthood, especially in substance abuse treatment (Biederman, Wilens, Mick, Spencer, & Faraone, 1999;Katusic et al, 2005;Mueser, Noordsy, Drake, & Fox, 2003).…”