A University of Otago study shows investigating the family background of a person with mental illness can help identify how severe their symptoms are likely to become.
The findings come from data tracking the physical and mental health of 1000 people born between 1972 and 1973 in Dunedin, from birth until the age of 32.
Researchers studied each person's experience with depression, anxiety, and alcohol and drug dependence in relation to their family history.
The results found that knowing family history can help predict whether symptoms of the four disorders are likely to recur.
The researchers say family history can also be used to identify those in need of early intervention to treat mental illness.