(CNN) — The World Health Organization is making loneliness a global health priority, it said Wednesday, launching a new Commission on Social Connection.

For the next three years, the commission will focus on ways to address the “pressing health threat” of a global epidemic of loneliness, reviewing the latest science and designing strategies to help people deepen their social connections. It’s co-chaired by African Union Youth Envoy Chido Mpemba and U.S. Surgeon General Dr. Vivek Murthy, who has written and spoken extensively about the risks of social isolation and has made the issue one of his top concerns while in office.

Murthy said it is an “underappreciated” threat to health that has now become widespread.

“For too long, loneliness has existed behind the shadows, unseen and underappreciated, driving mental and physical illness,” he said. “Now, we have an opportunity to change that.”

Committee member Dr. Karen DeSalvo, the chief health officer at Google, said that when she was a clinician and when she was health commissioner of New Orleans, she learned firsthand that “great care matters, but it has to happen in a context” – and that includes social connection.

Knocking on doors in New Orleans after a hurricane took out power and left homes swelteringly hot, she and colleagues tried to get people to go to shelters, but it was difficult to get some to leave, even when so many were so alone.

“People can easily get in the margins and get isolated, and it affects their health outcomes,” DeSalvo said.

Someone may seek help for chest pain, for example, and the health care system will focus on treating that pain, but it’s difficult for them to actually get better if they are discharged into social isolation, she said.

Loneliness has drawn a lot of attention recently in the public health sector. Last week, New York state appointed sex therapist Dr. Ruth Westheimer as its first loneliness ambassador. In May, Murthy laid out a framework to tackle loneliness and “mend the fabric of our nation.” And it’s not just a US phenomenon; in 2018, the United Kingdom appointed its first minister for loneliness.

Research shows that a lack of certain types of social connection is linked with poor mental health and increases the risk of anxiety, depression and suicide.

“Social disconnection has now become a key driver of the broader mental health crisis that we are seeing in this world,” Murthy said. Roughly a billion people – 1 in 8 – are living with a mental health problem, a quarter of them adolescents, he said.

Loneliness and social isolation can also lead to poor physical health. People who lack social connection face a higher risk of dying early. Loneliness and social isolation have long been associated with poor immune function and cardiovascular problems like high blood pressure, and they increase the risk of stroke by 30%. They also contribute to cognitive decline and are associated with a 50% increase in dementia. People who are isolated also tend to have more unhealthy habits such as smoking, drinking to excess and being more sedentary.

The health impact of loneliness is so far-reaching that one study compared it to smoking up to 15 cigarettes a day.

A lot of research on social isolation and loneliness focuses on seniors. Older adults are at higher risk because they more often live on their own, have lost more family or friends and are more likely to have physical problems like hearing loss, which can cut them off from being social, according to the U.S. Centers for Disease Control and Prevention.

But it’s not just older people who are lonely.

A survey taken across 142 countries published last month said that nearly 1 in 4 adults reported feeling very or fairly lonely. Children are also not immune; some studies have found that over half of children and adolescents felt lonely at least some of the time.

The Covid-19 pandemic may have exacerbated those feelings, studies show, with social isolation and loneliness negatively affecting younger people’s depression and anxiety symptoms.

While humans are social creatures by nature, people get better at socializing with practice, says Dr. Ryan Patel, an adjunct clinical assistant professor of psychiatry at The Ohio State University who studies social connectedness.

The pandemic’s isolation limited the number of “softer, easy social interactions” that people normally have, and the impact is still felt, especially among young people.

“When you take that away, it can then be anxiety-provoking to be in highly social environments when you’ve not had that kind of practice,” said Patel, who is not a part of the WHO committee.

Patel said younger people’s hyperconnectivity has also inadvertently narrowed the lens with which they see the world, so when they interact with others who may not share their perspective, it can be challenging.

“You might be worried that you might say the wrong thing, and that can heighten anxiety,” Patel said. The polarized environment also disincentivizes people to interact, and that too can result in loneliness and isolation.

“Social cohesion, connectedness, loneliness matters for healthy outcomes for people of all ages, wherever they are,” DeSalvo said. She hopes the new WHO commission will provide evidence to help health systems around the world understand how to better address the connection between loneliness and poor health outcomes like heart disease.

“They’ve got a clear track record, and I think what they can bring to this is an action orientation,” she said.

In addition to finding ways to help people learn how to help themselves, their neighbors and their communities feel less isolated, the committee can help the broader community tackle this major public health problem.

“So how do we help the public and private sector around the world know what they can do to take these interventions to understand how we can move forward to improve the health of people everywhere?” DeSalvo said.