Is schizophrenia risk 'around 80% genetic'?

Conclusion This study explores how much of the risk of developing schizophrenia or related disorders may be explained by genetics. It shows that schizophrenia and related disorders are quite rare – affecting about 1% of the general population. Their observed co-diagnosis rate in both twins – about a third for identical and less than 10% for non-identical twins – was lower than has been observed in other studies. This seems to suggest that while a high proportion of an individual's susceptibility may come down to hereditary factors, environmental factors must still be play a substantial role. This type of study makes a number of assumptions to simplify the picture, and these may not accurately portray reality. For example, it assumes that identical and non-identical twins would share similar environmental exposures. However, this may not be the case. It also assumes that genes and the environment do not interact, but in reality, people with different genetic makeups may react to the same exposure in different ways. Other reasons for the low co-diagnosis rate could be, as the researchers acknowledge, down to study methods. For example, some may have had different severity or presentation of illness influencing diagnosis. The study also does not have lifelong data for all of the twins. Though most people with schizophrenia are diagnosed before 40 years of age, longer follow-up times would be ideal. One final point: estimates that come out of this type of study are depende...
Source: NHS News Feed - Category: Consumer Health News Tags: Mental health Source Type: news