Are Executive Functions Deficits in Early-Onset Chronic Schizophrenia More Severe than in Adult-Onset Chronic Schizophrenia?

Objective: The research on the age of schizophrenia onset and cognitive impairments leads to contradictory conclusions. It is still unknown whether neurocognitive deficits in early-onset schizophrenia (EOS) are more intense than adulthood-onset schizophrenia (AOS). The study aimed to examine specific aspects of the executive functions of chronic outpatients with different ages of schizophrenia onset. Method: Two clinical groups (EOS and AOS) consisted of 60 chronic outpatients with schizophrenia recruited from the community-based support system. The executive functions were measured with the Wisconsin Card Sorting Test (WCST), Trail Making Test A&B (TMT A&B), verbal fluency task (VFT), and the N-back test. Obtained results were compared to control groups consisting of 40 healthy subjects, matched with age, sex, and years of education, respectively. Results: There were no differences in various aspects of executive dysfunctions between EOS and AOS outpatients. The outpatients in general, had lower scores than healthy controls regardless of their age of symptom onset. The most important finding suggests that some cognitive domains (visual working memory and processing speed) in presented schizophrenia patients were similar to those in healthy controls.Despite the demographic differences, both clinical groups present the same level of executive functioning. In addition, similar to the healthy participants, the outpatients had no problems in working memory and processing speed. Conclusions: These observations suggest that EOS might not be associated with more severe cognitive deterioration. Moreover, the stabilization or improvement of their functioning might be linked with long-term psycho-social rehabilitation and modern pharmacotherapy.