OBJECTIVE: To evaluate the genetic contribution to schizophrenia using an adoption design that disentangles genetic and environmental factors. METHOD: Finnish hospital diagnoses of schizophrenic/paranoid psychosis in a nationwide sample of adopting-away women are compared with DSM-III-R research diagnoses for these mothers. DSM-III-R diagnoses of their index offspring are blindly compared with adopted-away offspring of epidemiologically unscreened control mothers. RESULTS: Primary sampling diagnoses of index mothers were confirmed using DSM-III-R criteria. Lifetime prevalence of typical schizophrenia in 164 index adoptees was 6.7% (age-corrected morbid risk 8.1%), significantly different from 2.0% prevalence (2.3% age-corrected morbid risk) in 197 control adoptees. When adoptees with diagnoses of schizoaffective disorder, schizophreniform disorder, schizotypal disorder and affective psychoses were added, the contrast between the index and control adoptees increased. CONCLUSION: The genetic liability to 'typical' DSM-III-R schizophrenia is decisively confirmed. Additionally, the liability also extends to a broad spectrum of other psychotic and non-psychotic disorders.
OBJECTIVE: To evaluate the genetic contribution to schizophrenia using an adoption design that disentangles genetic and environmental factors. METHOD: Finnish hospital diagnoses of schizophrenic/paranoid psychosis in a nationwide sample of adopting-away women are compared with DSM-III-R research diagnoses for these mothers. DSM-III-R diagnoses of their index offspring are blindly compared with adopted-away offspring of epidemiologically unscreened control mothers. RESULTS: Primary sampling diagnoses of index mothers were confirmed using DSM-III-R criteria. Lifetime prevalence of typical schizophrenia in 164 index adoptees was 6.7% (age-corrected morbid risk 8.1%), significantly different from 2.0% prevalence (2.3% age-corrected morbid risk) in 197 control adoptees. When adoptees with diagnoses of schizoaffective disorder, schizophreniform disorder, schizotypal disorder and affective psychoses were added, the contrast between the index and control adoptees increased. CONCLUSION: The genetic liability to 'typical' DSM-III-R schizophrenia is decisively confirmed. Additionally, the liability also extends to a broad spectrum of other psychotic and non-psychotic disorders.
Authors: Tiina Paunio; Ritva Arajärvi; Joseph D Terwilliger; Tero Hiekkalinna; Perttu Haimi; Timo Partonen; Jouko Lönnqvist; Leena Peltonen; Teppo Varilo Journal: Am J Med Genet B Neuropsychiatr Genet Date: 2009-09-05 Impact factor: 3.568
Authors: Toni Myllyaho; Virva Siira; Karl-Erik Wahlberg; Helinä Hakko; Tiina Taka-Eilola; Kristian Läksy; Ville Tikkanen; Riikka Roisko; Mika Niemelä; Sami Räsänen Journal: Child Psychiatry Hum Dev Date: 2022-08-13