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This page is an AI-assisted Turkish summary of the study presented at the 26th World Congress of Psychiatry. The study belongs to the presenting authors; please refer to the original source when citing it.

EV0552

Neurocognitive and clinical profiles of patients with severe mental disorders and substance use disorders in a semi-isolated population

NEUROCOGNITIVE AND CLINICAL PROFILE OF PATIENTS WITH SEVERE MENTAL ILLNESS (SMI) AND SUBSTANCE USE DISORDER (SUD) IN A SEMI-ISOLATED POPULATION

Substance use did not worsen cognitive performance in severe mental disorders; neurocognitive impairment was found to be primarily associated with the underlying diagnosis itself.

The study aimed to estimate the magnitude of cognitive impairment associated with co-occurring severe mental disorder (SMD) and substance use disorder (SUD), and to examine the relationship between primary diagnosis and neurocognitive performance in a Colombian sample (Paisa Project). Using an analytical cross-sectional design and secondary data, 300 adults over the age of 18 diagnosed with schizophrenia, bipolar I disorder, or major depressive disorder according to DSM-5 criteria (100 participants in each diagnostic group) were stratified by the presence of SUD; individuals with organic diseases of the central nervous system or missing data were excluded. Neurocognitive performance was assessed using the Penn Computerized Neurocognitive Battery (Penn CNB) across the domains of face memory, emotion recognition, social cognition, working memory, reasoning, visual attention, processing speed, and premorbid intelligence. The analysis used OLS linear regression with HC3 robust standard errors, adjusted for age, sex, and education; substance use × diagnosis interaction terms; the Benjamini–Hochberg correction for multiple comparisons; and Cohen's d and r as effect sizes. Men accounted for 71% of the schizophrenia group, while women accounted for 68% of the bipolar disorder group and 61% of the major depressive disorder group; the bipolar disorder group was the oldest (median age 40 years, interquartile range 32 to 53), and polypharmacy was common in all three groups (schizophrenia 98%, bipolar disorder 97%, major depressive disorder 65%). Although the frequency of substance use did not differ across diagnoses, the types of substances used did: alcohol predominated in major depressive disorder (46%), while cannabis and stimulants were more common in schizophrenia and bipolar disorder. Substance use was associated only with slightly faster processing speed (d = 0.22; p = 0.049), with no significant differences detected in any other cognitive domain. The schizophrenia and bipolar disorder groups performed significantly worse than the major depressive disorder group across all domains, with the largest differences observed in social cognition and processing speed (r = 0.56). The authors consider the findings consistent with the cognitive reserve hypothesis and argue that integrated care for dual diagnosis should prioritize early rehabilitation of social cognition and processing speed rather than assume that substance use worsens the course of cognitive functioning. Limitations include the cross-sectional design, limitations of the secondary data regarding substance dose, chronicity of use, and duration of abstinence, and potential confounding by active psychopathology.

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