In a world that is more connected than ever, a silent epidemic is taking its toll. Overall, 1 in 3 US adults report chronic loneliness — a condition so detrimental that it rivals smoking and obesity with respect to its negative effect on health and well-being. From anxiety and depression to life-threatening conditions like cardiovascular disease, stroke, and Alzheimer’s and Parkinson’s diseases, loneliness is more than an emotion — it’s a serious threat to both the brain and body.

In 2023, a US Surgeon General advisory raised the alarm about the national problem of loneliness and isolation, describing it as an epidemic.

“Given the significant health consequences of loneliness and isolation, we must prioritize building social connection in the same way we have prioritized other critical public health issues such as tobacco, obesity, and substance use disorders. Together, we can build a country that’s healthier, more resilient, less lonely, and more connected,” the report concluded.

But how, exactly, does chronic loneliness affect the physiology and function of the brain? What does the latest research reveal about the link between loneliness and neurologic and psychiatric illness, and what can clinicians do to address the issue?

Medscape Medical News spoke to multiple experts in the field to explore these issues.