Article Exploring Personality and Readiness to Change in Patients With Substance Use Disorders With and Without ADHD L. Flores-García 1 ,2, E. Ytterstad 2 , M. B. Lensing 3 , and M. Eisemann 2 Abstract Objective: To explore personality and readiness to change among substance use disorders (SUD) patients with and without ADHD. Method: SUD + ADHD versus SUD  ADHD patients consecutively entering treatment between 2010 and 2012 were compared concerning personality (Temperament and Character Inventory) and readiness to change (Stages of Change Readiness and Treatment Eagerness Scale). Results: Among 103 SUD patients (76 men, age M = 43.3, SD = 11.1), 16 (15.5%) were diagnosed with ADHD. SUD + ADHD patients reported significantly elevated eagerness to effort (p = .008) compared with SUD  ADHD patients, who reported significantly elevated fear of uncertainty (p < .000). SUD + ADHD patients reported higher ambition (p = .025), self-forgetfulness (p = .029), and lower recognition (p = .022). They were younger (p = .019) and showed more often amphetamine addiction (p = .022) compared with SUD  ADHD patients. Conclusion: The distinct characteristics found in SUD + ADHD and SUD  ADHD patients underline the need for differentiated treatment interventions. (J. of Att. Dis. XXXX; XX(X) XX-XX) Keywords substance use disorders, ADHD, personality, change readiness ADHD is a neurodevelopmental disorder (American Psychiatric Association [APA], 2013), prevalent in around 5% of the adult population (Willcutt, 2012). The core symptoms of ADHD, inattention, impulsivity and hyperactivity (Biederman et al., 2012) often manifest in adults as forgetting important appointments, having difficulties in planning and organizing everyday life tasks (Miranda, Berenguer, Colomer, & Rosello, 2014). Adults with ADHD may also seek immediate rewards without considering the consequences of their behavior (Sonuga- Barke, 2003). Other challenges such as over-talkativeness, inner restlessness (Kooij et al., 2010) or emotional dysregulation (Asherson, Buitelaar, Faraone, & Rohde, 2016) are often present in adults with ADHD. Substance use disorders (SUD) are characterized by a compulsive substance use, tolerance, withdrawal, and craving of addictive substances in spite of negative consequences and by unsuccessfully trying to stop using (APA, 2000, 2013). ADHD is frequently comorbid with SUD (Wilens et al., 2005). Among SUD treatment seekers prevalence rates between 5% and 31% of ADHD have been reported (van de Glind et al., 2014). In clinical settings, SUD + ADHD adults are found to be younger (Johann, Bobbe, Putzhammer, & Wodarz, 2003) and to have substantially higher rates of other psychiatric comorbidity (van Emmerik-van Oortmerssen et al., 2014) compared with SUD  ADHD adults. SUD + ADHD adults exhibit more severe and earlier onset of substance use, which develops faster into addiction (Ohlmeier et al., 2007) and have been found to have higher rates of SUD treatment drop out than SUD  ADHD adults (Levin et al., 2004). Both SUD and ADHD are impairing brain disorders (APA, 2013; Volkow & Baler, 2014) with similar cognitive, emotional, reward, and motivational deficits (Asherson et al., 2016; Volkow & Baler, 2014). Moreover, individuals with SUD + ADHD often experience a lack of control over own lives (Løvaas & Dahl, 2013). Personality Cloninger, Przybeck, Svrakic, and Wetzel (1994) describe personality in light of temperament (mainly biologically determined and stable over time) and character (susceptible to environmental influences). Four traits comprise temperament: novelty seeking, harm avoidance, reward dependence, and persistence. Three domains comprise character: self-directedness, cooperativeness, and self-transcendence (for a detailed description, see 1 University Hospital of Northern Norway, Tromsø, Norway 2 UiT—The Arctic University of Norway, Norway 3 Oslo University Hospital, Norway Corresponding Author:[AQ1] L. Flores-García, University Hospital of Northern Norway, Postbox 6124, Tromsø 9291, Norway. Email: lizbett.flores@unn.no Journal of Attention Disorders 1–11 © The Author(s) 2016 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1087054716677819 jad.sagepub.com