Neurocognitive impairment affects quality of life, occupational functioning, and the ability to benefit from therapy. Neurocognitive assessment is thus of importance, but it is expensive and not widely accessible. Therefore, in a hectic clinical setting, a procedure that includes measures that target core cognitive deficits would be beneficial. Paper I investigate the utility of psychometric tests, and a questionnaire-based inventory to assess “hot” and “cold” neurocognitive measures of executive functioning (EF) in adults with substance use disorder (SUD) (Hagen et al., 2016) Patients with polysubstance use disorder (PSUD) and healthy controls were compared on hot (Iowa Gambling Task) and cold (Stroop and the Trail Making Test) measures of EF, and participants completed a questionnaire assessing everyday EF-related problems (the Behavior Rating Inventory of Executive Function–Adult self-report version (BRIEF-A). To our surprise, the psychometric measure of hot EF (the Iowa Gambling Task) did not differentiate the patients with PSUD from controls and was not associated with any of the social adjustment indicators. The psychometric measures of cold EF differentiated somewhat between the groups and were associated with one indicator of social adjustment. However, the BRIEF-A differentiated between groups on all the clinical scales and was associated with three out of five social adjustment indicators. We concluded that the BRIEF-A was the most sensitive measure of EF in patients with SUD and should, therefore, be considered as a fundamental part of the clinical routine when assessing patients with SUD. PSUD is the most common diagnosis among patients seeking treatment for substance use. Compared with single-drug users, polydrug users have an earlier debut of drug use, a higher rate of dropout from treatment, and they report higher levels of general psychological distress; this psychiatric comorbidity increases the risk of relapse. Studies have shown that impaired psychiatric and cognitive functioning also greatly diminishes patients’ subjective perception of satisfaction with life. Even though satisfaction with life is reduced among SUD patients, it has not been thoroughly investigated in patients with PSUD. As satisfaction with life is described as an essential motivator for and predictor of successful treatment, it should be included as a key outcome indicator when evaluating the success of SUD treatment. Thus, paper II investigates whether individuals with PSUD who achieve at least one year of abstinence show greater improvement in satisfaction with life, executive functioning, and psychological distress compared with those who relapse and controls. Results indicated that participants who successfully abstained from substance use for one year showed improved satisfaction with life, executive functioning, and psychological distress compared with participants who relapsed and controls. Our findings suggest that a gradual and careful increase of learning requirements should be implemented, and SUD treatment should initially concentrate on stabilizing the patient and achieving abstinence, while interventions for comorbid problems and more cognitively challenging treatment components are more likely to succeed later in the treatment sequence (Hagen et al., 2017). Attention-deficit/hyperactivity disorder (ADHD) is a common comorbid disorder among patients suffering from SUD. Compared with SUD patients without ADHD, SUD patients with ADHD are more likely to have developed SUD at a younger age, become polysubstance users, and need inpatient treatment more often. It is well established that the prefrontal cortex is involved in reward mechanisms, emotional processing, and behavioral inhibition, as well as drug use susceptibility. These functional areas have also been associated with the development of ADHD, and thus these two disorders could share a preexisting neurobiological vulnerability. Hence, the possible overlap and interconnections between these disorders are relevant to both research and clinical practice. Paper III investigates whether individuals with PSUD with one year of abstinence show a reduction in ADHD symptoms compared with those who relapse and controls. ADHD symptoms were measured using the adult ADHD Self- Report Scale (ASRS). Substance use was evaluated by self-reports on the Alcohol Use Disorders Identification Test (AUDIT) and the Drug Use Disorders Identification Test (DUDIT). Results indicate that patients who remained abstinent for one year reported a substantial reduction in ADHD symptoms compared with patients who relapsed and controls. We concluded that confirmation of an ADHD diagnosis should follow a period of abstinence to avoid identification of false-positive cases (Hagen et al., 2017)