FIGURE 13.3The Role of Genetics in SchizophreniaThe average lifetime risk of developing schizophrenia for the general population is 1% or lower. However, if you have a sibling diagnosed with schizophrenia, your own lifetime risk increases to 9%. If that sibling is your identical twin, someone with whom you share 100% of genes, your risk rockets to 48%. This suggests a significant role for genetic factors in the development of schizophrenia.
Source: Copyright © 2001 by the American Psychological Association. Adapted with permission from Gottesman (2001).