For this study, researchers wanted to dig into not only which lifestyle factors can help reduce depression risk, but why they may reduce depression risk.

To do so, they examined data from nearly 290,000 people (13,000 of which had depression) over nine years, looking at their lifestyle habits, genetics, brain structure, immune system, and metabolic data.

The data came from the UK Biobank, a large medical database which includes genetic, health, and lifestyle information on participants.

They also examined MRI brain scans from nearly 33,000 participants, as well as looked for blood markers that show immune or metabolic problems.

And not only did they identify the seven more important lifestyle factors for preventing depression, but they also discovered that those lifestyle factors had the biggest impact on immune and metabolic function, which subsequently impact depression risk.