Etiology of Schizophrenia Although its specific causes and mechanisms are unknown, schizophrenia has a biologic basis, as evidenced by Alterations in brain structure (eg, enlarged cerebral ventricles, thinning of the cortex, decreased size of the anterior hippocampus and other brain regions) Changes in neurochemistry, especially altered activity in markers of dopamine and glutamate transmission Recently demonstrated genetic risk factors (1) Some experts suggest that schizophrenia occurs more frequently in people with neurodevelopmental vulnerabilities and that the onset, remission, and recurrence of symptoms are the result of interactions between these enduring vulnerabilities and environmental stressors.