Schizophrenia: Caused by a fault in programmed synaptic elimination during adolescence?

Converging evidence indicates that a profound reorganization of human brain function takes place during adolescence: the amount of deep sleep and the rate of brain metabolism fall sharply; the latency of certain event-related potentials declines; the capacity to recover function after brain injury diminishes; and adult problem-solving "power" appears. A reduction in cortical synaptic density has recently been observed and might account for all of these changes. Such synaptic "pruning" may be analogous to the programmed elimination of neural elements in very early development. A defect in this maturational process may underlie those cases of schizophrenia that emerge during adolescence.