Harmen Beurmanjer

11 General Introduction 1 (Dijkstra et al., 2017; Sumnall, Woolfall, Edwards, Cole, & Beynon, 2008). Other drivers of GHB use are the global availability via the internet, web marketing, easy at home to manufacture and low costs(J. G. C. van Amsterdam, van Laar, Brunt, & van den Brink, 2012). While the prevalence of GHB use is low, GHB is the fourth most common substance in emergency presentations in Europe (European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), 2018). In Europe up to 20% of all hospital admissions for drug use is GHB related (Addiction, 2019; Dines et al., 2015), in the Netherlands this is even one fifth. These numbers could suggest that GHB is used more often than reported in surveys, but could also be GHB specific, and related to the frequent overdosing of GHB due to narrow therapeutic window (Busardo & Jones, 2015). GHB use disorder In this thesis the term GUD is frequently used to address the substance use pattern commonly called addiction. Though GUD is not explicitly mentioned as a disorder in DSM-5 (American Psychiatric Association. & American Psychiatric Association. DSM-5 Task Force, 2013), it could be placed under the “Sedatives” category within the chapter “Substance Use Disorders”. Patients with GUD do adhere to key symptoms of substance use disorders, such as taking larger doses or longer periods of GHB than meant to, not managing to stop using GHB, spending a lot of time using GHB, experiencing craving towards GHB, not managing social/work obligations due to GHB use, continued GHB use even when it causes relationship problems, giving up important social activities due to GHB use, using GHB in situations that put one in danger, continuing GHB use even when one knows that it will worsen their physical or psychological condition, developing tolerance and experiencing withdrawal when GHB use is discontinued (Beurmanjer et al, 2016; Dijkstra et al., 2017; Galloway et al., 1997; Gonzalez & Nutt, 2005; K. Miotto et al., 2001; J. G. C. van Amsterdam et al., 2012). Tolerance to GHB can develop within weeks of the first use, with rapid dose escalation and shorter time intervals between dosages. Several other factors contribute to the highly addictive properties of GHB. From a pharmacology perspective, GHB takes effect within a very short period of time after ingestion, but the high is relatively short due to short half-life. This reinforces taking multiple doses on single events, increasing the chance of developing tolerance. Furthermore, the user doesn’t experience downsides after use, such as a hangover. GHB-induced coma’s are not experienced as negative (de Weert-van Oene et al., 2013), likely due to amnesia and the stimulating effects of GHB at low doses just before waking up after a GHB-induced coma. This limits negative associations with GHB use, users will not remember passing out and/or feel fine after waking up adding to the idea of the innocence of GHB-induced coma’s. Recent studies suggest however that GHB-induced comas are associated with (verbal) memory impairments in patients