DIFFERENT mental disorders such as depression or phobia do not always have distinct genetic predisposing factors, the largest twin study of its kind has concluded. Rather, mental illnesses fall into two groups with the same genetic factors making people vulnerable to all the disorders in each. The work suggests it may be possible to identify the gene variants that predispose people to an entire group of disorders.
“You could imagine that each disorder has separate [genetic] causes or that all disorders share one common trigger,” says psychiatric geneticist Kenneth Kendler, whose team spent years studying the mental health of 2800 pairs of twins. “We find the…
