Depression is a leading cause of disability worldwide, with middle-aged and older adults disproportionately affected, a global demographic that is quickly expanding.
To better understand the reasons behind how this age group develops depressive disorder, commonly referred to as depression, Stephen Aichele, assistant professor in the Colorado State University Department of Human Development and Family Studies, and his team used a machine learning approach to analyze data from a large, population-representative sample of middle-aged and older European adults.
It is one of very few studies to use such an approach for comparing numerous risk and protective factors for depression in later life, and it is likely the first to apply it so broadly within this population (with 18 European countries represented and 56 risk and protective factors examined).
Risk factors for depression
Out of 56 variables examined, Aichele and his team found that, for both men and women, social isolation was the primary risk factor for depression, followed by general poor health and mobility difficulties.
Other recent studies have identified social isolation as a key risk factor for depression in older adults, but Aichele and his team also looked at 30 variables related to specific dimensions of participants’ social networks and family configurations, such as frequency of contact, number of friends, and interpersonal transactions related to physical care and financial support.
“It’s less about frequency of contact or how many friends you have,” said Aichele. “It’s more about physical proximity to the person you feel emotionally closest to, be it your spouse, partner, or other primary social relation.”
For men, a fourth key risk factor was difficulty in instrumental activities of daily life, such as managing finances, taking medications and making telephone calls. For women, a fourth key risk factor was family burden – women who strongly agreed that “family responsibilities get in the way of my being able to do the things I want to do” were at elevated risk for depression. However, these gender-specific factors accounted for only a small proportion of differences in depression risk.