Aim: Early‐onset schizophrenia (onset before adulthood) is a rare and severe form of the disorder that shows phenotypic and neurobiological continuity with adult‐onset schizophrenia. Here, we provide a synthesis of keynote findings in this enriched population to understand better the neurobiology and pathophysiology of early‐onset schizophrenia.

Methods: A synthetic and integrative approach is applied to review studies stemming from epidemiology, phenomenology, cognition, genetics and neuroimaging data. We provide conclusions and future directions of research on early‐onset schizophrenia.

Results: Childhood and adolescent‐onset schizophrenia is associated with severe clinical course, greater rates of premorbid abnormalities, poor psychosocial functioning and increased severity of brain abnormalities. Early‐onset cases show similar neurobiological correlates and phenotypic deficits to adult‐onset schizophrenia, but show worse long‐term psychopathological outcome. Emerging technological advances have provided important insights into the genomic architecture of early‐onset schizophrenia, suggesting that some genetic variations may occur more frequently and at a higher rate in young‐onset than adult‐onset cases.

Conclusions: Clinical, cognitive, genetic and imaging data suggest increased severity in early‐onset schizophrenia. Studying younger‐onset cases can provide useful insights into the neurobiological mechanisms of schizophrenia and the complexity of gene‐environment interactions leading to the emergence of this debilitating disorder.