Moderate drinking and a good night’s sleep are among seven healthy lifestyle changes that can more than halve the risk of depression, scientists have found.
Experts at the University of Cambridge examined health data from almost 290,000 British people – of whom 13,000 had depression – to find out what factors could be playing a role.
They found that getting a good night’s sleep – between seven and nine hours – had the biggest protective effect, lowering the risk of depression by 22 per cent.
Not smoking also reduced the chance of depression by 20 per cent, while having frequent social connections cut the risk by 18 per cent.
Regular physical activity reduced the risk by a further 14 per cent, while a moderate amount of alcohol – fewer than 14 units per week – lowered the risk by 11 per cent. Finally, a healthy diet brought a small benefit of 6 per cent.
People in the study who had the best lifestyles were 57 per cent less likely to develop depression, with researchers concluding that lifestyle had “a more potent influence” on low mood than other factors such as genetics and brain structure.
Dr Christelle Langley, 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.”
Depression and anxiety affect around one in six adults in the UK, with women twice as likely to experience low mood compared with men.
Previous studies have shown that the reasons for depression are complex, with personal circumstances, lifestyle factors and biology all playing a role.
Experts at Cambridge wanted to tease apart what factors were having the biggest effects and used the UK Biobank study to look at lifestyles, genetics, brain structure, immune and metabolic systems to try and explain why some people experience depression while others stay upbeat.
Genetics was found to have a major impact, with people with the lowest genetic risk score 25 per cent less likely to develop depression when compared with those with the highest score – although researchers said it was a much smaller impact than lifestyle.
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.”
The team also examined MRI brain scans from around 33,000 participants and found people with a healthier lifestyle tended to have more neurons and connections in several regions of the brain, including the amygdala which processes emotions.
The researchers also looked for markers in the blood that indicated stress and found that a poorer lifestyle appeared to impact the immune system and the metabolism, which increases the risk of depression.
Professor Jianfeng Feng, from Fudan University and Warwick University, added: “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.”
The research was published in the journal Nature Mental Health.%n