Schizophrenia affects approximately 23 million people worldwide, with onset usually occurring during a person’s late adolescence or 20s. Impairments associated with schizophrenia include hallucinations, delusions, and disorganized thinking and behavior.

Now, researchers at the University of Washington are investigating how genetic changes affect the severity of schizophrenia symptoms. A new study, published in the American Journal of Psychiatry, supports the idea that deletions in genes that regulate early brain and neuron development are associated with more severe features of schizophrenia spectrum disorders, particularly lower cognitive abilities.