Loneliness is rampant, and it’s killing us—literally. Anywhere from one quarter to one half of Americans feel lonely a lot of the time, which puts them at risk for developing a range of physical and mental illnesses, including heart disease, cancer, diabetes, and depression. This is a public health problem that needs to be addressed on a wide scale.
But at the individual level, there is much we can do to ward off loneliness. One strategy is to volunteer. In a recent survey of over 10,000 people in the UK, two-thirds reported that volunteering helped them feel less isolated. Similarly, a 2018 study of nearly 6,000 people across the US examined widows who, unsurprisingly, felt lonelier than married adults. After starting to volunteer for two or more hours per week, their average level of loneliness subsided to match that of married adults, even after controlling for demographics, baseline health, personality traits, and other social involvement. These benefits may be especially strong the older you are and the more often you volunteer.
https://www.scientificamerican.com/article/a-solution-for-loneliness/?redirect=1

Great point regarding volunteering. However, having just read your other articles about screen time and social media, I can't help but wonder if increased reliance on technology and virtual socialness also contributes to lonliness and in turn mental and physical health problems?