In a study published in Nature Mental Health, an international team of researchers analyzed a combination of factors, including lifestyle, genetics, brain structure, and immune and metabolic systems to identify mechanisms associated with depression.

They found that factors such as a sedentary lifestyle, poor sleep, and habits like alcohol and smoking increase the risk of depression.

Details of the study:
To better understand the relationship between these factors and depression, researchers turned to the UK Biobank, a database containing information on genetics, lifestyle, and the health of its participants.

By examining data from nearly 290,000 people, including 13,000 with depression, tracked over a nine-year period, the team identified seven lifestyle factors associated with a higher risk of depression. These were:

1. Moderate alcohol consumption
2. Healthy diet
3. Regular physical activity
4. Healthy sleep
5. Never smoking
6. Low to moderate sedentary behavior
7. Frequent social connection

Of all these factors, getting a good night’s sleep – between seven and nine hours per night – made the most significant difference, reducing the risk of depression, including single depressive episodes and treatment-resistant depression, by 22%.

Frequent social connection, which generally reduced the risk of depression by 18%, was the most protective against recurrent depressive disorder.

Moderate alcohol consumption decreased the risk of depression by 11%, a healthy diet by 6%, regular physical activity by 14%, never smoking by 20%, and low to moderate sedentary behavior by 13%.

The team then examined the DNA of participants, assigning each a genetic risk score. This score was based on the number of genetic variants an individual carried, known to be linked to the risk of depression. Those with the lowest genetic risk score had a 25% lower likelihood of developing depression compared to those with the highest score – an impact much smaller than lifestyle.

In individuals with high, medium, and low genetic risk for depression, the team also found that a healthy lifestyle can reduce the risk of depression. This research highlights the importance of living a healthy lifestyle to prevent depression, regardless of a person’s genetic risk.