Schizophrenia is associated with early neurodevelopmental disorders, including most frequently learning disorders (LD), among them dyslexia and dyspraxia. Despite the demonstrated links between schizophrenia and LD, specific clinical patterns of the schizophrenia with a history of LD subgroup remain unknown. The aim of the present study was to investigate cognitive impairment, symptoms and functional outcome associated with a history of LD in a large cross-sectional, multicentric, sample of schizophrenia subjects. 492 community-dwelling subjects with schizophrenia (75.6% male, mean age 30.8 years) were consecutively included in the network of the FondaMental Expert Centers for Schizophrenia in France and received a thorough clinical assessment. The 51 (10.4%) subjects identified with a history of LD had significantly impaired general cognitive ability (Wechsler Adult Intelligence Scale Full Scale Total IQ: Cohen's d = 0.50, p = 0.001), processing speed (d = 0.19), verbal comprehension (d = 0.29), working memory (d = 0.31), cognitive inhibition and flexibility (d = 0.26), central executive functioning (d = 0.26), phonemic verbal fluency (d = 0.22) and premorbid intellectual ability (d = 0.48), as well as with a worse functional outcome (Global Assessment of Functioning, d = 0.21), independently of age, sex, education level, symptoms, treatments, and addiction comorbidities. These results indicate that a history of LD is associated with later cognitive impairment and functional outcome in schizophrenia. This suggests that history of LD is a relevant clinical marker to discriminate subgroups of patients with schizophrenia with different profiles in a precision psychiatry framework.
Keywords: Intellectual quotient; Mental health; Neurodevelopment; Psychiatry.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.