The BBC Loneliness Experiment provided a unique opportunity to examine differences in the experience of lonelines across cultures, age, and gender, and the interaction between these factors. Using those data, we analysed the frequency of loneliness reported by 46,054 participants aged 16–99 years, living across 237 countries, islands, and territories, representing the full range of individualism-collectivism cultures, as defined by Hofstede (1997). Findings showed that loneliness increased with individualism, decreased with age, and was greater in men than in women. We also found that age, gender, and culture interacted to predict loneliness, although those interactions did not qualify the main effects, and simply accentuated them. We found the most vulnerable to loneliness were younger men living in individualistic cultures .

Background Loneliness is common among youth and is associated with poor physical and mental health, and poor educational outcomes. To date, there have been no meta‐analyses of interventions aimed at reducing loneliness among young people. Methods We conducted meta‐analyses of single group and randomised control trials (RCTs) of studies published between 1980 and 2019, which measured loneliness as an outcome in youth ages 25 years or younger. Moderators, including sample demographics and intervention characteristics, that might affect intervention success, were examined. Results A total of 39 studies (14 single group and 25 RCTs) were included, and we found evidence that youth loneliness could be reduced via intervention. Moderator analysis – including intervention characteristics, study quality and sample demographics – was also examined. Conclusions While interventions were shown to reduce loneliness among youth, the interventions included in the meta‐analyses often targeted youth viewed to be at risk – for example those with health concerns – and rarely did the interventions target youth who reported loneliness. There is also no indication of whether youth experienced chronic or transient loneliness. In future work, interventions should be designed specifically for loneliness, with universal programmes helping youth manage their transient feelings of loneliness, and targeted interventions for those suffering from chronic loneliness. There is also a need to look at socioeconomic and other risk factors outside the individual for targeted interventions. Key Practitioner Message There have been no meta‐analyses that have evaluated the effect of interventions for reducing loneliness among children and adolescents. We found intervention programmes targeted at youth are successful at reducing loneliness. Future interventions should be designed specially with loneliness in mind, with (a) universal programmes to help youth manage their experiences of transient loneliness, and (b) targeted interventions for youth reporting chronic loneliness. They should also examine the longer‐term outcomes of the interventions. Future interventions should be designed, evaluated and then documented using guidelines on how to write up an intervention evaluation.

Aims: We examined the relationship between loneliness and health among young adolescents. We also investigated the validity of a single-item measure of loneliness by comparing this to a composite score. Methods: The current data come from a nationally representative sample of 11- to 15-year-old adolescents ( N=3305; F=52%) from Denmark collected in 2014 as part of the Health Behaviour in School-aged Children (HBSC) collaborative cross-national survey. Results: A series of binary logistic regressions showed that higher loneliness among adolescents, whether measured using the single- or multi-item measurement, was associated with poorer self-rated health, higher frequency of headache, stomach ache, backache, difficulties sleeping, greater sleep disturbance and more instances of feeling tired in the morning. Those associations were relatively consistent across sex and age groups. Conclusions: Loneliness is associated with poorer self-reported health and sleep problems among young adolescents. Those findings are similar across two measures of loneliness, suggesting robust findings. The development of interventions and health-education efforts to fight loneliness in adolescence is important.