Why do schizophrenia symptoms appear in adolescence or young adulthood if they are a consequence of early prenatal brain maldevelopment? In schizophrenia patients, the malformations are often found in the prefrontal cortex60,61, in which myelination and maturation occur at the time when the first severe symptoms emerge. As the prefrontal cortex becomes increasingly incorporated into the human brain circuitry, its developmental malformations may reveal itself in a complex clinical syndrome. Perhaps, the most severe forms of childhood schizophrenia, with abundant hallucinations and motor dysfunctions62, arise also in the cortical regions, which mature earlier and are home to the sensory and motor functions63. These and other compelling questions await further investigation.
