Gottesman 1991

By Pooja, Jessica and Shohum

Aims

• To investigate the risk of developing schizophrenia in different types of genetic relatives of a schizophrenic.

Procedures

• Compiled data from 40 family studies from the best Western European studies reported over the past century.

Findings

Conclusions

• Risk for cousins (2%) is only slightly greater than the general population risk.

• Second-degree relatives have a risk of around 5%, while first-degree relatives have a risk close to 10%.

• With one schizophrenic parent the risk was 6% with two it rose to 46%.

• Monozygotic twins had a 48% concordance rate.• Dizygotic twins had a 17%.• Concordance rates in this study are not 100% which can

suggest that the cause of schizophrenia may not be entirely genetic and other factors such as the environment and cognition may also play a role in the risk of an individual developing schizophrenia.