Up to four out of every five cases of schizophrenia can be tracked back to a person’s inherited genes, new research has revealed.
Researchers from the University of Copenhagen analysed 30,000 pairs of identical twins in what they say is the “most comprehensive and thorough estimate of the heritability of schizophrenia”. The twins were born between 1951 and 2000, and were followed until 2011.
The researchers also included related disorders on the schizophrenia spectrum, since schizophrenia itself is based on a narrow range of symptoms.
They found that the proportion of cases of schizophrenia caused by genetics (heritability) was 73 per cent, which the researchers described as a “substantial genetic component”.
It was already understood that the risk of developing schizophrenia is influenced by both genes and environment.
The study is the largest of its kind to date, although its findings are limited by the fact that others could go on to develop the disease after the study ended.
Researcher Drs. Hilker, Helenius said:
It is interesting since it indicates that the genetic risk for disease seems to be of almost equal importance across the spectrum of schizophrenia.
Hence, genetic risk seems not restricted to a narrow illness definition, but instead includes a broader diagnostic profile.