Association Between Cognitive Impairment and Substance Use Disorder Attributed to Pregabalin in Egypt: A Case-Control Study

Objectives: Substance use disorder attributed to pregabalin (SUD-P) is a rising public health problem in Egypt. Cognitive impairment (CI) associated with SUD-P was underrated. This study aimed to identify and compare the CI and its correlates among patients with SUD-P and among control subjects. Materials and Methods: This study included 80 patients with SUD-P and 80 control subjects (matched for age, sex, and socioeconomic level) who were recruited from Heliopolis Psychiatric Hospital, Cairo, Egypt. The participants were interviewed using the Structured Clinical Interview for DSM-5 Axis I Disorders (SCID-5), Montreal Cognitive Assessment test, and urine screening for drugs. Results: Overall, 49% of patients with SUD-P used pregabalin alone, whereas the remaining used pregabalin with other substances, mainly cannabis (74%), heroin (59%), and tramadol (56%). About half of patients with SUD-P experienced CI. Compared with control subjects, patients with SUD-P were more likely to have impairments in delayed recall [odds ratio (OR): 3.1, 95% confidence interval (CI): 1.5-7.9], orientation (OR: 2.6, 95% CI: 1.2-4.9), and total Montreal Cognitive Assessment scores (OR: 2.6, 95% CI: 1.7-9.8). Pregabalin daily dose was correlated with impairments in naming, language, and abstraction domains in patients with SUD-P (P<0.047, P=0.006, and 0.006, respectively). Conclusions: CI was prevalent in patients with SUD-P. The domains of delayed recall and orientation were the most affected. The pregabalin daily dose was correlated with impaired naming, language, and abstraction functions.