Children who often see their parents arguing are at greater risk of depression, experts warn.
Teenagers who witnessed lots of arguments in early childhood were more likely to suffer from the illness than others, said a Cambridge University team.
"Violent arguments in front of the children contribute to the likelihood of depression," said Professor Barbara Sahakian, of the university's psychiatry department and co-author of the report.
"If you are staying together for the sake of the family, then fighting and arguing in front of the kids is not good. It would be better for them not to have that kind of environment."
The team identified a gene that made some children more sensitive to emotions and also more likely to develop depression. Researchers came up with a simple test, that can be carried out at school, to identify those with the gene, allowing youngsters to get help before they suffer with the disease.
Researchers found that teenagers who struggled to process emotional information were more likely to develop mental health problems. In the study of 238 children, aged between 15 and 18, those who did worst at the test were up to four times more likely to develop depression within a year.
Those who did badly had a gene - present in one in five people - that made them less emotionally resilient. They also lived in households where they had been exposed before the age of six to intermittent arguments for longer than six months. One in three children live like this, said the team.
Professor Ian Goodyer, principal investigator on the study, said: "Whether we succumb to anxiety and depression depends in part on our tendencies to think well or poorly of ourselves at trouble times.
"How it comes about that some people see the 'glass half full' and think positively, whereas other see the 'glass half empty' and think negatively about themselves at times of stress is not known.
"The evidence is that our genes and early childhood experiences contribute."
- DAILY MAIL