Cognitive impairments in patients with schizophrenia and substance induced psychotic disorder

Abstract Background Schizophrenia (SZ) and Substance induced psychotic disorders (SIPDs) are the leading mental health problems with enormous health, social, and economic burden worldwide. The aim of the study was to compare the main characteristics in both psychotic disorders. Methods In a cross-sectional analysis we studied 62 out-patient treated men in two equal groups (n = 31) with SZ and SIPD. The study is approved by the ethical committee. Three basic variables were followed: age (under 40 years), education (primary school, high school and college/university) and economic status (students, employed, unemployed). The disease burden was assessed by Positive and Negative Syndrome Scale (PANSS). As neurocognitive tests we applied: 10 Words Memory Test of Luria; Digit Symbol Substitution Test (DSST); Benton Visual Retention Test; Trail Making Test Part A & B; Logical Memory Test (LMT); Verbal Fluency Test (VFT) with semantic VF (VF-s) and literal VF (VF-l) subparts. We compare groups by t-test, chi-square, Mann-Whitney test at the level of significance p < 0.05. Data processing was performed by IBM SPSS Statistics v.26. Results The mean age of the sample was 29.9±5.595 years. There were no significant differences between the groups by age, education, economic status, and the mean antipsychotic dose prescribed. The significant differences were in PANSS scores (p = 0.014). The sum of positive and negative sub-scores was higher in SZ patients with mean values of 18.6 vs 14.8 (p = 0.000) for positive and 14.5 vs 11.2 (p = 0.000) points for the negative symptoms. SZ subjects had significantly greater impairment in all cognitive domains except for semantic memory and verbal fluency. Conclusions Our data support the assumption that the two conditions share a common underlying neurobiological vulnerability more expressed in SZ, but differ in the extent of disruptions in engaged neuronal networks. Substance abuse increase the risk of developing SZ and needs stronger social and legal control. Key messages • SIPD arises from both substantial drug exposure and elevated liability to psychosis. The relation between drug abuse and psychosis can be understood with traditional stress/vulnerability paradigm. • There is a growing need of developing more effective preventive strategies among young populations concerning information about drug abuse and addiction and their associated risk factors.