Loneliness: we all know the feeling of it, but it’s hard to pin down precisely its causes and effects. Now, as PAUL BIEGLER reports, a growing field of study shows that this subjective feeling has objective effects – right down to a cellular level

On a cool night in the suburbs of Los Angeles in December, 1978, Jack Morris was at a house party. It was one o’clock in the morning and things were getting tense. Morris was 18 years old and hadn’t long been released from juvenile detention. “We were all drinking,” he remembers. “Two guys went out into the back yard to fight, that fight ensued, and then the guy that was fighting said he didn’t want to fight no more, and he ran into me, and he ran into another guy.”

Morris is seated at his desk at the St John’s Community Health Clinic in a squat brick building south of downtown LA, where he helps people who’ve left prison get jobs, housing, manage drug problems and avoid re-entering the prison system. He’s spruce, with thick greying hair cut to a medium crew and he’s wearing a dark shirt, and smart, tinted reading glasses. Morris speaks confidently, but when he recalls what happened, his voice fades. “And then I pulled out a knife and stabbed him. He died right there.”

Morris graduated to adult prison. He went to San Quentin, Corcoran then Tehachapi, doing solitary confinement in each. But out in the general population there was human contact. A handshake, a conversation, a gaze being met. In August 1991, however, all that changed. Morris was transferred to Pelican Bay, a supermax prison in northern California where the inmates were housed in windowless, poured concrete cells that measured 2.4 x 3.0 metres, around half the size of a standard car parking space.

“When the door is closed, even though it is perforated plate steel, you could feel your soul being sucked out,” he recalls. “You’re standing there naked with what they handed you and you’re just looking at the cell and you realise there is nothing in here but a concrete box, stainless steel sink, a toilet. You’re standing there … barefoot on cold cement, and you’re saying, ‘well, this is it’.” What Morris didn’t realise was that a sentence to solitary came with hidden extras. Soon, like hundreds of fellow prisoners, he would get high blood pressure. His risk of heart disease would go up. He would get symptoms of anxiety, sleeplessness, and depression. His knees and back would ache and he’d be taking anti-inflammatory medication. But few people cared about the plight of hardened criminals doing time.

Then the pandemic hit, and much of the world was forced into its own brand of lockdown isolation. Rates of depression and anxiety skyrocketed. The American Academy of Paediatrics declared a national emergency in children’s mental health. Now everyone was interested in the very same question: what does isolation do to bodies and minds? Scientists tackling that question have come up with some disturbing answers. Isolation, it seems, changes us down to our core, right down to the level of our genes.

Blue genes?

These days Steve Cole is a professor of medicine at the University of California, Los Angeles, but in the late nineties he was a virologist studying HIV. And he was perplexed. Something odd was happening with a subset of the gay men who were getting the virus. Their immune system was declining faster, and they were dying earlier. “The ones that were most vulnerable were those who were most socially marginalised, especially the guys who were in the closet,” Cole recalls. “How was it that the HIV genome operated differently in the body of a person who was living in the closet, and constantly afraid of being discovered and losing his job, or his family, or his friends?”

Cole embarked on a series of studies to find out, and unearthed something astonishing. Gay men with a “socially inhibited” temperament were switching on their “fight and flight” sympathetic nervous system. They were pumping out stress hormones, including one called noradrenalin, which binds to a white blood cell that’s key in the fight against HIV, the T lymphocyte. Those lymphocytes were then winding back production of proteins called interferons, critical defenders against viruses.

“There was a set of programs that were built into the human immune system, that caused threatened people to throttle back on their antiviral immune responses,” says Cole. Incredibly, the social truth of sexual orientation was playing out at the level of these men’s infection- fighting cells. Cole presented his findings at a thinktank and, afterwards, was approached by a man with an unusual request. His name was John Cacioppo and he was a pioneer in the scientific study of loneliness, whose links to physical diseases such as heart disease, Alzheimer’s and high blood pressure were only just being teased out.

Cacioppo wanted to know if the stress of social isolation could do similar things to the immune system and might somehow, be elevating the risk of chronic disease. Cole jumped at the chance to work with him.

The full article appears in issue 95 of Cosmos Magazine