For this study, researchers wanted to identify various risk factors for insomnia using machine-learning and a retrospective, cross-sectional cohort study.

Looking at data from nearly 8,000 middle-aged participants, machine learning assessed everything from mental health, to physical health, to lifestyle factors as they related to sleep disorders.

And based on their findings, depression was the biggest risk factor for insomnia, with 31.1% of participants with insomnia also struggling with depression. Age and exercise were the next most significant risk factors.

As study author Samuel Y. Huang M.D. explains in a news release, “What sets this study on the risk factors for insomnia apart from others is seeing not only that depressive symptoms, age, caffeine use, history of congestive heart failure, chest pain, coronary artery disease, liver disease, and 57 other variables are associated with insomnia, but also visualizing the contribution of each in a very predictive model.”