A cross-sectional and longitudinal analysis of data from the UK Biobank, involving almost 85,000 people, has found that lifestyle factors such as less screen time, adequate sleep, a better-quality diet, and physical activity strongly impact depression.

With evolving data exploring the link between depression and lifestyle factors, the international research team led by Western Sydney University say their findings published today in BMC Medicine may help inform public health policy.

The study found:

• A significant relationship between physical activity, healthy diet, and optimal sleep (7-9 hours) was associated with less frequency of depressed mood.

• Screen time and tobacco smoking were also significantly associated with higher frequency of depressed mood.

• Over time, the lifestyle factors which were protective of depressed mood in both individuals with clinical depression and those without a depressive disorder was optimal sleep (7-9 hours) and lower screen time, while a better-quality diet was indicated to be protective of depressed mood in those without depression

• A higher frequency of alcohol consumption was surprisingly associated with reduced frequency of depressed mood in people with depression. This may potentially be due to the self-medicating use of alcohol by those with depression to manage their mood.

"The research is the first assessment of such a broad range of lifestyle factors and its effect on depression symptoms using the large UK Biobank lifestyle and mood dataset," said lead co-author, Professor Jerome Sarris, NICM Health Research Institute, Western Sydney University.

"While people usually know that physical activity is important for mood, we now have additional data showing that adequate sleep and less screen time is also critical to reduce depression.

"The findings also suggest that one's dietary pattern is partly implicated in the germination or exacerbation of depressed mood.

"The results may inform public health policy by further highlighting the important relationship between people being encouraged and supported to engage in a range of health-promoting activities. In particular, maintaining optimal sleep and lessening screen time (which is often an issue in youth), while having adequate physical activity and good dietary quality, may reduce the symptoms of depression," said Professor Sarris.