Researcher who established the value of genetics for understanding psychiatric conditions

Peter McGuffin, who has died aged 74, showed the importance of trying to establish how genetic and non-genetic factors act together to predispose people to psychiatric disorders: so-called gene-environment interplay. He was also one of the first to see the potential of the DNA revolution for understanding psychiatric disorders, and his work laid the foundations for the application of genomics to psychiatry.

It used to be assumed that depression could be divided into two forms: one the result of adverse circumstances (reactive depression) and the other the result of intrinsic factors such as genetic risk (endogenous depression).