Harmen Beurmanjer

52 Chapter 4 rates observed in patients with GUD. To our knowledge no studies on the relationship between cognitive impairment and relapse in patients with GUD have been published to date. This prospective cohort study aimed to investigate in patients with GUD 1) the association between cognitive impairment, the number of GHB-induced comas and severity of GHB use; and 2) the association between cognitive impairment and relapse in GHB use after detoxification. Methods Design This study is a prospective, observational, multicentre cohort study, of patients with GUD. Due to the observational design, the study was exempted from medical ethical review by the Medical Ethical Committee of the Medical Spectrum Twente. Part of the data of the monitor has already been published as an open label trial with baclofen(9). Participants A consecutive series of patients with GUD (according to DSM-IV criteria of substance dependence) who were admitted for detoxification at one of six participating addiction care facilities in the Netherlands (IrisZorg, Mondriaan, Novadic-Kentron, Tactus Verslav- ingszorg, Victas and Verslavingzorg Noord-Nederland) were recruited (n=137). Inclusion criteria were 18-65 years old, a need for inpatient GHB detoxification, and comprehension of the Dutch language. Exclusion criteria were the presence of acute psychiatric problems interfering with study participation, such as mania or acute psychosis. A physician screened patients on these criteria before detoxification. All patients signed informed consent, before they were included in the study. Measurements Demographic data Demographic data (sex, date of birth, ethnicity, housing situation, source of income and level of education) were collected through self-report. Measurements of Addictions for Triage and Evaluation (MATE) The MATE is a structured clinical interview that measures the history, frequency and consequences of drug use, including medical, social and psychological problems(Schip- pers, Broekman, Buchholz, Koeter, & Van Den Brink, 2010), based on the Composite International Diagnostic Interview (CIDI) (Andrews & Peters, 1998). For this study ‘Module 1: Drug Use’ was used to assess GHB and other substance use patterns. During this structured interview patients were asked about their drug use over the past 30 days (number of days and amount used) and lifetime (total years of use of at least 3 days per