Cognitive errors associated with cannabis and opioid have been investigated and compared, but the relationship between cognitive errors questioning personal achievements (PA) and interpersonal relationships (IP) with these two types of substance has not been adequately investigated. We aimed to compare comorbid psychiatric symptoms, cognitive errors and substance use characteristics of patients diagnosed with cannabis use disorder (CUD) and opioid use disorder (OUD). In this cross-sectional study, Symptom Checklist-90-Revised (SCL-90-R) was used and a sociodemographic data was obtained. The cognitive distortions scale (CDS) was used to evaluate cognitive errors. The patient group consisted of 60 (30 CUD and 30 OUD) and the control group consisted of 30 males. Patient and control groups were similar in terms of mean age and educational status (p>0.05). The mean duration of substance use of the CUD group was 43.56±31.13 months, while the OUD group was 68.00±33.20 months (p=0.005). The somatic (SOM) (p=0.011) and paranoid (PAR) (p=0.005) subscales of SCL-90-R were significantly different in the CUD and OUD groups. There was a significant difference between CUD and OUD groups in terms of IP (p=0.002) and PA (p=0.002) sub scores and total scores (p = 0.001) of CDS. Our study reveals that cannabis use is associated with more cognitive errors than opioid use. Higher scores of SOM and PAR in the OUD group than in the CUD group were thought to be associated with longer substance use.
Key words: Opioid addiction, cannabis, substance use disorder, cognition