A study conducted by scientists at the University of Edinburgh has found that a gene called DISC1 may control the way patients respond to psychiatric medicine.

The findings, which are confirmed by a separate academic investigation carried out by a team at the Howard Hughes Institute in America, shed light on experts' understanding of mental illnesses such as schizophrenia and mental bipolar.

The DISC1 gene is known to play a part in the development of mental illness and will aid researchers to understand how illness affects the brain.

Professor David Porteous, of the Institute of Genetics and Molecular Medicine at the university, said: "By understanding more fully the genetic processes of mental health and illness we hope to identify ways in which medication might make a real difference to the lives of those affected by these conditions."

Researchers, who based their work on existing data from the human genome project, also discovered seven proteins that are vital to the growth of mental illnesses.

Scientists hope to establish medicines that attack these proteins.