Serious loneliness is a problem that can strike at any time in adult life - not just old age, warns a new study.

Researchers found that not only is loneliness more prevalent than previously feared, but is ‘particularly acute’ during the late-20s, mid-50s and late-80s.

Feeling alone has been linked to a string of psychological and physical problems.

And, in recent times, public health officials have warned about a ‘rising epidemic’ of loneliness, with rates of loneliness reportedly doubling over the past 50 years.

Now researchers at University of California San Diego School of Medicine have put a specific, concerning and surprising face to the issue.

Their findings, published by the journal ‘International Psychogeriatrics’, show that moderate to severe loneliness persisted across the adult lifespan, but was particularly acute during three age periods: late-20s, mid-50s and late-80s.

Loneliness was also more prevalent than expected, according to the scientists.

Three out of four study participants reported moderate to high levels of loneliness, using a well-established assessment scale.

The figure represents a ‘substantial increase’ from previously reported prevalence estimates in the US general population, which have ranged from 17 to 57 per cent.

Study leader Dr Dilip Jeste said: ‘This is noteworthy because the participants in this study were not considered to be at high risk for moderate to severe loneliness.

‘They didn’t have major physical disorders.

‘Nor did they suffer from significant mental illnesses such as depression or schizophrenia, in which you might expect loneliness to be problematic.

‘Though there were clear demographic limitations to the group, these participants were, generally speaking, regular people.’

The study was conducted among 340 San Diego County residents, between the ages of 27 and 101, who had participated in one of three earlier studies of ageing and mental health.

People with serious physical or psychological ailments, including diagnosed dementia, were excluded, as were people living in nursing homes or requiring substantial living assistance.

The researchers assessed the participants using multiple measures, including the San Diego Wisdom Scale, created by Prof Jeste and colleagues to assess a person’s level of wisdom.

Excluding evidence of mild loneliness, which Prof Jeste said is common and expected to occasionally appear throughout adult life, the researchers found that loneliness severity and age ‘had a complex relationship,’ peaking at specific periods in both men and women.

There were no sex differences in loneliness prevalence, severity, or age relationships.

Former US Surgeon General Vivek Murphy has said a prevailing pall of loneliness poses a greater, more intractable public health crisis than tobacco use or obesity.

Earlier this year, the Government established a Ministry of Loneliness to address the physical and mental health needs of lonely people.

Study first author Dr Ellen Lee said the findings were a mix of bad and good news.

On the negative side, she said, moderate to severe loneliness appears to be highly prevalent throughout adult life.

Dr Lee said: ‘Loneliness seems to be associated with everything bad.

‘It’s linked to poor mental health, substance abuse, cognitive impairment, and worse physical health, including malnutrition, hypertension and disrupted sleep.’

But, on the plus side, she noted that the UC San Diego group found a strong ‘inverse association’ between wisdom and loneliness.

People who were deemed wiser were less lonely.

She added: ‘That may be due to the fact that behaviours which define wisdom - such as empathy, compassion, emotional regulation, self-reflection - effectively counter or prevent serious loneliness.’

Prof Jeste said more research needs to be done, adding: ‘There are more gaps in knowledge than there are answers at the moment.

‘But these findings suggest we need to think about loneliness differently.

‘It’s not about social isolation. A person can be alone and not feel lonely, while a person can be in a crowd and feel alone.

‘We need to find solutions and interventions that help connect people that help them to become wiser.

‘A wiser society would be a happier, more connected, and less lonely society.’

Agencies