Harmen Beurmanjer

26 Chapter 2 Studies reporting education level and/ or employment status (9 out of 11) showed that most respondents completed at least secondary education (median 67%) and were employed or student (median 64%, range 17% to 90%). People started using GHB around the age of 24 years (range 22 to 27 years). The median frequency per occasion was six doses with an interval of 1.5 h between doses. Duration of GHB use was only mentioned in two studies (1 versus 4 years). Most respondents reported prior GHB use over the past year (median 82%, 4 studies), and several during the past month (median 37%, 3 studies). Weekly use varied between 3,5% and 45% of the participants (median 40%, 3 studies). On average 17% (range 4–41%, 6 studies) reported daily GHB use / dependence. Two studies reported current psychiatric problems (9%), past psychiatric treatment (28%), and or mental history (59%) (Miotto et al., 2001; Stein et al., 2011, 2012). The majority (n = 10) of studies reported co-ingestion of other substances, mostly alcohol (median 40%), MDMA (median 36%), amphetamines (median 30%, 3 studies) and cannabis (median 24%, 3 studies). Other reported substances were ketamine (median 7%, 2 studies) and cocaine (median 43%, 1 study). People using GHB at home more frequently mixed GHB with other substances than those using GHB in nightlife settings (52% versus 26%) (Sumnall, Woolfall, Edwards, Cole, & Beynon, 2008). The studies describe different populations using GHB, ranging from those using GHB infrequently at parties to those using frequently alone at home. Most commonly mentioned motives for GHB use were recreational (18–65%, 2 studies), being more self-confident (13–78%, 3 studies), happiness, euphoria, having lots of energy, getting high (46–79%, 4 studies), to enhance dancing (19%−64%, 3 studies), and to improve sex (16–71%, 7 studies). Other reported motives included forgetting daily worries, letting go, dampening of emotions, depression or anxiety (41%, 72%), improving sleep (76%), small private party (30–35%), being alone (17%, 20%), to treat withdrawal symptoms (17%), to explore altered states of consciousness (13%), or body building (2–6%). Most participants in the study of Stein et al. (2011) started using GHB for positive reasons, which later turned into dealing with negative feelings (depression, anxiety). GHB-induced comas were frequently reported in three studies (at least one occasion: 25%−69%). Overdose was mostly unintentional (Grund, de Bruin, & van Gaalen, 2018). Participants who experienced GHB overdose more often used GHB alone, had used GHB more frequently and for a longer period of time than those without overdose (Degenhardt et al., 2002; Degenhardt, Darke, & Dillon, 2003; Grund et al., 2018). Other factors related to coma were using > 4 ml GHB, using GHB to feel more confident and having a lower level of education (Grund et al., 2018). Patients in addiction care using GHB People using GHB presenting at addiction care were also mostly young males (50–89%, average age 27–34 years). van Noorden, Mol, Wisselink, Kuijpers, and Dijkstra (2017) found that GUD patients were significantly younger than other substance use disorder patients(-