Loneliness can be best dealt with by changing how a person perceives and thinks about others, and this, in turn reduces the accompanying risk factors of heart disease and other problems.
Recently, researchers have characterized the negative influence of loneliness upon blood pressure, sleep quality, dementia, and other health measures.
Those effects suggest that loneliness is a health risk factor, similar to obesity or smoking, which can be targeted to improve patients' health in several dimensions.
"People are becoming more isolated, and this health problem is likely to grow," said John Cacioppo, Professor of Psychology at the University of Chicago. "If we know that loneliness is involved in health problems, the next question is what we can do to mitigate it."
To determine the most effective method for reducing loneliness, Cacioppo and a team of researchers from the University of Chicago examined the long history of research on the topic.
Their quantitative review found that the best interventions targeted social cognition rather than social skills or opportunities for social interaction.
The team's review, called a meta-analysis, analyzed the methods and results from dozens of papers that tested loneliness interventions. Strategies fell into four categories: improving social skills, increasing social support, creating opportunities for social interaction, and addressing social cognition.
When the researchers pooled the 20 studies that employed the most rigorous study design of randomized, controlled trials, they found a small, but significant effect on reducing loneliness. Sub-dividing the studies by their strategy revealed that interventions targeting social cognition - a person's thoughts about themselves and others - were far more effective than the other strategies.
Specifically, the four interventions that helped people break the cycle of negative thoughts about self-worth and how people perceive them were the most effective at reducing loneliness. Studies that used cognitive-behavioral therapy, a technique also used for treating depression, eating disorders and other problems, were found to be particularly effective, the authors reported.
"Effective interventions are not so much about providing others with whom people can interact, providing social support, or teaching social skills as they are about changing how people who feel lonely perceive, think about, and act toward other people," Cacioppo said.
The study has been published in the journal Personality and Social Psychology Review.