Researchers from King's College London have found a link between loneliness and poor sleep quality in a study of more than 2,000 British young adults.
Lonelier people were 24 per cent more likely to feel tired and have difficulty concentrating during the day, according to the study published today in Psychological Medicine.
Loneliness is defined by researchers as a distressing feeling that people experience when they perceive their social relationships to be inadequate. This is distinct from the concept of social isolation, as people can be socially isolated without feeling lonely, or feel lonely despite being surrounded by many people.
While the effect of being lonely is well documented among the elderly, it is a common problem for young people too -- the Mental Health Foundation reports that loneliness is most frequent between the ages of 18-34. Despite this, little is known about health problems that are associated with loneliness among young adults, or the impact on sleep.
The researchers from King's College London sampled data from the Environmental Risk (E-Risk) Longitudinal Twin Study, a cohort of 2,232 18-19 year-old twins born in England and Wales. They measured loneliness by scoring responses to four questions: 'How often do you feel that you lack companionship?', 'How often do you feel left out?', 'How often do you feel isolated from others?' and 'How often do you feel alone?'
They also measured sleep quality in the past month, including the time it takes to fall asleep, sleep duration and sleep disturbances, as well as daytime dysfunction such as staying awake during the day.
Overall 25-30 per cent of the sample reported feeling lonely sometimes, with a further five per cent reporting frequent feelings of loneliness. The researchers found that the association between loneliness and sleep quality remained even after they accounted for symptoms of mental health problems such as depression and anxiety, which are commonly associated with sleep problems and feeling lonely.
One of the proposed reasons for restless sleep in lonely individuals is the possibility they feel less safe, so the researchers examined the impact of past exposure to violence, including crime, sexual abuse, child maltreatment and violent abuse by family members or peers. The association between loneliness and poor sleep quality was almost 70 per cent stronger among those exposed to the most severe forms of violence. The study authors suggest a number of biological processes which may explain the association between loneliness and sleep quality, including a heightened biological stress response. Previous research suggests that loneliness is associated with changes in circulating cortisol, indicating elevated activation of the stress response system. Physiological arousal resulting from this process may play a role in the disrupted sleep of lonely individuals.
Professor Louise Arseneault from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's College London, said: 'Diminished sleep quality is one of the many ways in which loneliness gets under the skin, and our findings underscore the importance of early therapeutic approaches to target the negative thoughts and perceptions that can make loneliness a vicious cycle.'
Professor Arseneault added: 'Many of the young people in our study are currently at university, living away from home for the first time, which can compound feelings of loneliness. It is therefore important that they receive appropriate support to address these feelings before they turn into severe mental health problems.'
Timothy Matthews from the IoPPN at King's College London, added: 'We also found that past exposure to violence exacerbated the association between loneliness and poor sleep, which is consistent with the suggestion that sleep problems in lonely individuals are related to feeling unsafe. This makes sense as sleep is a state in which it is impossible to be vigilant for one's safety, so feeling isolated from others could make it more difficult to sleep restfully, and even more so for individuals who have been exposed to violence in the past. It is therefore important to recognise that loneliness may interact with pre-existing vulnerabilities in some people, and that these individuals should receive tailored support.'
Notes to editors
For further media information please contact Jack Stonebridge, Senior Press Officer, Institute of Psychiatry, Psychology & Neuroscience, King's College London firstname.lastname@example.org/ 020 7848 5377.
King's College London is one of the top 25 universities in the world (2016/17 QS World University Rankings) and among the oldest in England. King's has more than 26,500 students (of whom nearly 10,400 are graduate students) from some 150 countries worldwide, and nearly 6,900 staff. The university is in the second phase of a £1 billion redevelopment programme which is transforming its estate.
King's has an outstanding reputation for world-class teaching and cutting-edge research. In the 2014 Research Excellence Framework (REF) King's was ranked 6th nationally in the 'power' ranking, which takes into account both the quality and quantity of research activity, and 7th for quality according to Times Higher Education rankings. Eighty-four per cent of research at King's was deemed 'world-leading' or 'internationally excellent' (3* and 4*). The university is in the top seven UK universities for research earnings and has an overall annual income of more than £600 million.
King's has a particularly distinguished reputation in the humanities, law, the sciences (including a wide range of health areas such as psychiatry, medicine, nursing and dentistry) and social sciences including international affairs. It has played a major role in many of the advances that have shaped modern life, such as the discovery of the structure of DNA and research that led to the development of radio, television, mobile phones and radar.
King's College London and Guy's and St Thomas', King's College Hospital and South London and Maudsley NHS Foundation Trusts are part of King's Health Partners. King's Health Partners Academic Health Sciences Centre (AHSC) is a pioneering global collaboration between one of the world's leading research-led universities and three of London's most successful NHS Foundation Trusts, including leading teaching hospitals and comprehensive mental health services. For more information, visit: http://www.kingshealthpartners.org.