Clinical and neurocognitive course in early-onset psychosis: A longitudinal study of adolescents with schizophrenia-spectrum disorders

Aim: Adolescents with psychotic disorders show deficits in IQ, attention, learning and memory, executive functioning, and processing speed that are related to important clinical variables including negative symptoms, adaptive functioning and academics. Previous studies have reported relatively consistent deficits with varying relationships to illness status and symptoms. The goals of this study were to examine these relationships in a larger sample at baseline, and also to examine the longitudinal course of these deficits in a smaller subset of adolescents. Method: Thirty-six subjects, aged 10 to 17 years, were included at baseline. All had Diagnostic and Statistical Manual-Fourth Edition diagnoses of schizophrenia, schizoaffective disorder, schizophreniform disorder and psychosis - not otherwise specified, as determined by Kiddie-Schedule for Affective Disorders and Schizophrenia for School-Age Children structured interviews. Patients were administered a neuropsychological battery, and Positive and Negative Syndrome Scale ratings were completed at baseline and again at 1 year (n = 14). Most participants were inpatients at baseline, and 13 of 14 were on atypical antipsychotic medication during both sessions. Results: At baseline, the patients demonstrated impairments in working memory, processing speed, executive function and verbal learning. No significant cognitive change was detected at 1-year follow-up. In contrast, clinical symptoms were variable across 1 year, with an improvement in positive symptoms at 1 year. No relationships between clinical and cognitive symptoms were observed, with the exception of baseline IQ predicting negative symptoms at 1 year. Conclusions: Young patients with schizophrenia-spectrum disorders displayed neurocognitive impairments at baseline. Despite measurable fluctuations in clinical symptoms over the year, no significant changes were measured in cognition. Lower IQ at baseline was predictive of more negative symptoms at 1 year.