Tuesday, July 7, 2009

To predict the severity of mental disease, consider the family

We've all been asked at routine visits to the doctor to record our family's history with medical problems like cancer, diabetes or heart disease. But when it comes to mental disorders, usually mum's the word.

New findings by researchers at the Duke Institute for Genome Sciences & Policy (IGSP) make a strong case for changing that status quo. They have found that 30 minutes or less of question-and-answer about the family history of depression, anxiety, or substance abuse is enough to predict a patient's approximate risks for developing each disorder and how severe their future illness is likely to be.

"There are lots of kids with behavior problems who may outgrow them on their own without medication, versus the minority with mental illnesses that need treatment," said Terrie Moffitt, a professor of psychology and neuroscience in the IGSP. "Family history is the quickest and cheapest way to sort that out."

Researchers who are on the hunt for genes responsible for mental disorders might also take advantage of the discovery, added Avshalom Caspi, an IGSP investigator and professor of psychology and neuroscience. "It suggests they may be better off selecting people with more serious illness or, better still, collecting family history information directly," he said.

That mental illnesses tend to run in families is certainly no surprise. In fact, psychiatric conditions are some of the most heritable of all disorders. But the link between family history and the seriousness of psychiatric disease has been less certain.

Moffitt, Caspi and their colleagues looked to 981 New Zealanders born at a single hospital in 1972 or 1973, who are participants in what is known as the Dunedin Study. Researchers have been tracking the physical and mental health and lifestyles of those enrolled in the longitudinal study since they were 3 years old.