Loneliness in later life: what the science says
Older people who are lonely or cut off from others tend to die earlier and to have more heart disease, strokes, dementia and depression. This page sets out the most recent research in plain words, says where each number comes from, and is honest about what is not yet known.
Last reviewed . Every figure links to its source at the foot of the page.
The findings in four numbers
The most recent large study: 86 studies, one answer
In August 2025 the journal European Psychiatry published the largest review so far of loneliness and death in older adults. The researchers screened 11,964 papers and combined the 86 that followed older people over time and recorded who died. [1]
Compared with older adults who were not affected, the risk of dying from any cause was:
- 14% higher for those who felt lonely
- 35% higher for those who were socially isolated
- 21% higher for those who lived alone
The authors note that results differed a good deal from study to study, depending on sex, age, country, existing illness and how well each study was run. The combined result pointed the same way for all three: less connection, shorter life.
The World Health Organization's 2025 report
On 30 June 2025 the WHO Commission on Social Connection published its first global report. [2] Its main findings:
- About 1 in 6 people worldwide is affected by loneliness.
- Loneliness is linked to an estimated 871,000 deaths a year, roughly 100 every hour.
- Social isolation affects up to 1 in 3 older adults.
- Loneliness and isolation raise the risk of stroke, heart disease, diabetes, cognitive decline and early death.
- People who are lonely are twice as likely to become depressed.
The report also states the other side: strong social connection is linked to better health and a longer life.
Beyond lifespan: heart, brain and mood
The U.S. Surgeon General's 2023 advisory on loneliness and isolation gathered the evidence on specific illnesses. [4]
| Condition | Increase in risk |
|---|---|
| Heart disease | 29% higher |
| Stroke | 32% higher |
| Dementia, among older adults with chronic loneliness or isolation | About 50% higher |
| Depression, among adults who often feel lonely | More than twice as likely |
Ten years of evidence point the same way
The 2025 review confirms an earlier landmark. In 2015, Julianne Holt-Lunstad and colleagues at Brigham Young University combined 70 studies covering more than 3 million people of all ages. [3] The two reviews measured slightly different groups, so the numbers differ, but every one of them is above zero.
| Factor | 2015 review (all adults) | 2025 review (older adults) |
|---|---|---|
| Feeling lonely | 26% | 14% |
| Social isolation | 29% | 35% |
| Living alone | 32% | 21% |
In the United States, the National Academies of Sciences, Engineering, and Medicine estimated in 2020 that about one quarter of people aged 65 and over who live in the community are socially isolated, and described isolation as a risk for early death comparable to high blood pressure, smoking or obesity. [5]
Loneliness and isolation are not the same thing
Loneliness is a feeling: having less connection than you want. Social isolation is a fact that can be counted: few relationships, little contact. A widow who sees no one for a week may feel content; a man in a busy care home may feel deeply alone. Researchers measure the two separately, and both are linked to poorer health.
What these studies cannot tell us
- A link is not proof of cause. These studies observe people; they do not assign loneliness at random. Poor health can also cause loneliness, by keeping people at home.
- The size of the effect is uncertain. The tables above show estimates from 14% to 35% depending on who was studied and how.
- An average is not a forecast. A higher risk across thousands of people says nothing certain about any one person.
Can an AI companion help? The honest answer
The evidence is early. In May 2026, BMC Geriatrics published a review of every randomised trial of AI conversational agents and social robots for older adults: eight trials, 611 people. [6]
- Depression: a small but measurable reduction in symptoms.
- Loneliness: no reliable effect. Some trials found a benefit, others none, and the results were too mixed to draw a conclusion.
So we make no health claims for GoodBuddy. It has not been tested in a clinical trial, it is not a treatment for any condition, and we do not say it will lengthen anyone's life.
What the research does tell us is where to aim. Regular conversation matters, and the people in someone's life matter most. GoodBuddy is built to be a friendly voice on the days when nobody rings, to ask after the family and encourage the next real visit or call, and to tell the family when something seems wrong. It is meant to sit alongside human contact, never to replace it.
Questions people ask
Does loneliness shorten life?
Studies that follow older adults over many years find that lonely people die earlier on average. The largest recent analysis, covering 86 studies and published in 2025, found loneliness linked to a 14% higher risk of death from any cause, social isolation to a 35% higher risk, and living alone to a 21% higher risk. These studies show a link. They do not prove that loneliness itself is the cause.
What is the difference between loneliness and social isolation?
Loneliness is a feeling: having less connection than you want. Social isolation is a fact that can be counted: having few relationships or little contact with other people. A person can be isolated without feeling lonely, and lonely while surrounded by people. Both are linked to poorer health.
How common are loneliness and isolation among older people?
The World Health Organization reported in 2025 that social isolation affects up to 1 in 3 older adults, and that about 1 in 6 people of all ages is affected by loneliness. In the United States, the National Academies estimated in 2020 that about one quarter of people aged 65 and older who live in the community are socially isolated.
Which illnesses are linked to loneliness and social isolation?
According to the U.S. Surgeon General, poor social relationships, isolation and loneliness are linked to a 29% higher risk of heart disease and a 32% higher risk of stroke. Among older adults, chronic loneliness and isolation are linked to about a 50% higher risk of developing dementia. Adults who often feel lonely are more than twice as likely to develop depression.
Can talking to an AI companion reduce loneliness?
It is not proven. A 2026 review of eight randomised trials with 611 older adults found that AI conversational agents produced a small reduction in symptoms of depression, but no reliable effect on loneliness, with results that varied widely between trials. GoodBuddy has not been tested in a clinical trial and is not a treatment for any condition.
Sources
- Nakou A, et al. Echoes of solitude: systematic review and meta-analysis revealing mortality risks in older adults due to loneliness, social isolation, and living alone. European Psychiatry, 26 August 2025. doi:10.1192/j.eurpsy.2025.1746
- World Health Organization, Commission on Social Connection. From loneliness to social connection: charting a path to healthier societies. 30 June 2025. WHO announcement
- Holt-Lunstad J, Smith TB, Baker M, Harris T, Stephenson D. Loneliness and social isolation as risk factors for mortality: a meta-analytic review. Perspectives on Psychological Science, 2015; 10(2): 227–237. doi:10.1177/1745691614568352
- Office of the U.S. Surgeon General. Our Epidemic of Loneliness and Isolation: The U.S. Surgeon General's Advisory on the Healing Effects of Social Connection and Community. 2023. hhs.gov
- National Academies of Sciences, Engineering, and Medicine. Social Isolation and Loneliness in Older Adults: Opportunities for the Health Care System. 2020. nationalacademies.org
- Gou W, Lefebvre F, Yang T, et al. Effectiveness of AI-based conversational and socially assistive agents in older adults: a systematic review and meta-analysis. BMC Geriatrics, 7 May 2026. doi:10.1186/s12877-026-07418-6
This page is general information, not medical advice. If you are worried about your own health or someone else's, speak to a doctor. In the United States, call or text 988 if you or someone you know is struggling, and 911 in an emergency.