Carolien Zeetsen

67 CHAPTER Prevalence of cognitive i mpairments in patients with SUD 4 Results Patient characteristics A total of 656 patients was included (77% male). The mean age was 40 years ( SD = 13.9). The most prevalent primary–problem substance was alcohol (60%), followed by cannabis (19%), stimulants (15%) and opioids (4%). Only six patients primarily used sedatives and another ten used GHB as the primary–problem substance (2%). Due to these small numbers, these patients were only included in analyses regarding the total sample. Patient characteristics differed significantly between patients with different primary–problem substances, except for the MATE 2.1 subscales depression and anxiety (Table 4.1). Between patients from all four health care centres, there were significant differences for primary–problem substance, marital status, abstinence, depression, stress and DASS–21 total score. Cognitive impairments In the current sample, 206 patients (31%) performed below the MoCA cut–off score of 24. Per primary–problem substance, the prevalence was 34% for alcohol, 21% for cannabis, 27% for stimulants and 38% for opioids. Post–hoc tests revealed that only patients using alcohol performed significantly worse on the MoCA–TS than those using cannabis (Table 4.2). However, taking into consideration the sensitivity and specificity of the MoCA in addiction care (Bruijnen, Jansen, et al., 2019), a rather high proportion of patients with actual cognitive impairments may remain undetected, while at the same time cognitively intact patients are classified as being cognitively impaired by the MoCA. Differences between primary–problem substances for cognitive domains Of all the possible differences that could be found between the primary–problem substances in performance on the MoCA–DS, only three were significant. Patients using alcohol performed significantly worse on memory than those using cannabis ( M diff = 0.44, SD = 0.14, p = 0.008). Patients using opioids performed significantly worse on visuospatial abilities than those using cannabis ( M diff = 0.64, SD = 0.20, p = 0.009) and those using stimulants ( M diff = 0.61, SD = 0.21, p = 0.017). Additionally, patients using opioids performed worse on memory than those using cannabis, which was marginally significant ( M diff = 0.96, SD = 0.35, p = 0.051). A significant main effect was found for executive functioning, with no significant post–hoc differences between substances.