Carolien Zeetsen

65 CHAPTER Prevalence of cognitive i mpairments in patients with SUD 4 used to determine severity of the addiction, with a maximum score of 9. Finally, section Q2 the Depression, Anxiety and Stress Scale (DASS–21; Lovibond & Lovibond, 1995; de Beurs, 2010), is a self–report questionnaire that measures symptoms of depression, anxiety and stress by answering 21 questions on a four–point scale (anchored with 0 = ‘Did not apply to me at all’ and 3 = ‘Applied to me very much, or most of the time’), and is used to identify psychiatric comorbidity. The sum of all 21 questions multiplied by two, gives the DASS–21 total score, with a maximum of 126. Montreal Cognitive Assessment The MoCA (Nasreddine et al., 2005) consists of 12 items measuring seven cognitive domains: executive functioning; visuospatial abilities; attention, concentration and working memory (referred to as ‘attention’ from now on); language; abstract reasoning; memory; and orientation. The authorised Dutch translation of MoCA version 7.1 was used in this study. Administration of the MoCA takes approximately 15 minutes and scoring can mostly be done during administration. A total score is calculated by summing scores on all items, with a maximum of 30 points, where higher scores represent better cognitive performance. An adjustment for level of education is applied in which participants with a low level of education are awarded two extra points and participants with an average level of education are awarded one extra point, maintaining the maximum score of 30 (Chertkow et al., 2011). In addiction care, an optimal cut–off score of 24 was found to be predictive of substance–induced cognitive impairments, with a sensitivity of 0.56 and a specificity of 0.62, using an extensive neuropsychological assessment as gold standard (Bruijnen, Jansen, et al., 2019). Procedure As part of the intake procedure, the MATE 2.1 was administered to each participant seeking treatment. After the intake, participants were informed about the study. Written informed consent was required for participation and for using information of the administered MATE 2.1. MoCA version 7.1 was administered by professionals (e.g. psychologists, social psychiatric nurses, social workers) immediately or in the following appointment. All professionals were trained in MoCA administration and scoring by the psychologist coordinating this study in accordance with the formal instructions and based on experience of the psychologist for ambiguities that are not clarified in these instructions. Patients provided demographic information, such as sex, age, level of education, marital status and employment. Also, self– reported use of the primary–problem substance in the week before MoCA administration, or abstinence duration (if > 7 days) was recorded.