Neurocognitive and social cognitive impairments in remission and symptomatic states of early-onset schizophrenia spectrum disorders

Abstract

Previous studies demonstrated neurocognitive impairments in early-onset schizophrenia (EOS) and other psychotic spectrum disorders (PSD). This study aimed to compare remitted and symptomatic cases in terms of neurocognition and theory of mind (ToM). 50 healthy controls (HC) and 106 patients diagnosed schizophrenia in remission (EOS-R, n = 38), symptomatic schizophrenia (EOS-S, n = 34), and other PSD (n = 34) were included in our study. The Positive and Negative Symptom Scale, Columbia-Suicide Severity Rating Scale, Reactive and Proactive Aggression Questionnaire were used to evaluate psychopathology. A cognitive battery was conducted to measure verbal learning/memory, visual learning/memory, executive functions (EF), inhibition, processing speed (PS), verbal fluency skills. Reading Mind in Eyes Test (RMET) and Faux-Pas tests were implemented to assess ToM. Principal Component Analysis was used to identify cognitive domain scores. Patient groups had poorer performance in cognitive domains than the HC group. The cognitive impairment and psychopathology levels of EOS-R and the PSD groups were comparable for all cognitive domains. The EOS-S group also had poorer scores in Rey verbal learning score (d = 0.87), RMET (d = 0.72), verbal fluency (d = 0.66), PS/EF (d = 0.82) and visual learning/memory (d = 0.83) test scores than the PSD group. Only RMET (d = 0.72) and executive function/processing speed domain (d = 0.63) were significantly impaired in the EOS-S group than the EOS-R group Cognitive impairments seen in remitted psychotic disorders were on the same continuum. Impaired EF/PS and ToM skills could be a cognitive marker for symptomatic illness in youth.