Mental Illness in the Biological and Adoptive Families of Adopted Schizophrenics
SEYMOUR S. KETY M.D.1,
DAVID ROSENTHAL PH.D.2,
PAUL H. WENDER M.D.3, , and
FINI SCHULSINGER M.D.4
1 Professor of Psychiatry at Harvard Medical School and Director of the Psychiatric Research Laboratories, Massachusetts General Hospital, Boston, Mass. 02114
2 Chief of the Laboratory of Psychology, National Institute of Mental Health, Bethesda, Md.
3 Research Psychiatrist, National Institute of Mental Health, Bethesda, Md.
4 Director of the Psychiatric Service at the Kommunehospitalet, Copenhagen, Denmark
Adoption has been used as a means of separating genetic and environmental factors in the transmission of schizophrenia among family members. In the study reported here, a significantly higher than usual prevalence of schizophrenia-related illness was found among the biological relatives of adopted schizophrenics, but not among their adoptive relatives. The findings support a genetic transmission of vulnerability to schizophrenia, but also imply the requirement of nongenetic, environmental factors for the development of clinical schizophrenic illness.
