Scientists have found that poor diet, low-quality sleep and lack of physical activity can impact the immune system and metabolism (how food is broken down to produce energy), which in turn increases the risk of depression.
Conversely, data showed that a good night’s sleep – between seven and nine hours a night – reduced the risk of depression by 22% while regular social connection cut the risk by 18%.
The team said their findings, published in the journal Nature Mental Health, show lifestyle could play a greater role than genetics when it comes to being more susceptible to depression.
Some of these lifestyle factors are things we have a degree of control over, so trying to find ways to improve them - making sure we have a good night's sleep and getting out to see friends, for example - could make a real difference to people's lives
Professor Barbara Sahakian, University of Cambridge
Professor Barbara Sahakian, from the Department of Psychiatry at the University of Cambridge, said: “Although our DNA – the genetic hand we’ve been dealt – can increase our risk of depression, we’ve shown that a healthy lifestyle is potentially more important.
“Some of these lifestyle factors are things we have a degree of control over, so trying to find ways to improve them – making sure we have a good night’s sleep and getting out to see friends, for example – could make a real difference to people’s lives.”
It is estimated one in four people will experience a mental health problem of some kind each year in England.
For the study, the researchers looked at data from almost 290,000 people in the UK Biobank – an online database of medical and lifestyle records of half a million Britons.
Of them, nearly 13,000 had an onset of depression during a follow-up of nine years.
The researchers were able to identify seven healthy lifestyle factors associated with a lower risk of depression: moderate alcohol consumption, healthy diet, regular physical activity, healthy sleep, never smoking, low-to-moderate sedentary behaviour, and frequent social connection.
Blood tests showed problems with the immune system or metabolism increase the risk of depression.
Markers of poor lifestyle included high levels of fat in the blood (triglycerides) and a molecule known as C-reactive protein which is produced by the body in response to stress.
We know that depression can start as early as in adolescence or young adulthood, so educating young people on the importance of a healthy lifestyle and its impact on mental health should begin in schools
Professor Jianfeng Feng, Fudan University
Dr Christelle Langley, also from the Department of Psychiatry at the University of Cambridge, said: “We’re used to thinking of a healthy lifestyle as being important to our physical health, but it’s just as important for our mental health.
“It’s good for our brain health and cognition, but also indirectly by promoting a healthier immune system and better metabolism.”
Professor Jianfeng Feng, from Fudan University and the University of Warwick, said: “We know that depression can start as early as in adolescence or young adulthood, so educating young people on the importance of a healthy lifestyle and its impact on mental health should begin in schools.”