(Health.com) -- It's long been known that elderly people are more prone to depression and other mental-health problems if they live on their own. New research suggests the same pattern may also be found in younger, working-age adults.
In a study of nearly 3,500 men and women ages 30 to 65, researchers in Finland found that people who lived alone were more likely that their peers to receive a prescription for antidepressant drugs. One quarter of people living alone filled an antidepressant prescription during the seven-year study, compared to just 16% of those who lived with spouses, family, or roommates.
"Living alone may be considered a mental-health risk factor," says lead author Laura Pulkki-Råback, Ph.D., a lecturer at the University of Helsinki's Institute of Behavioral Sciences. The study was published today in the journal BMC Public Health.
The findings show only an association, not cause and effect, which raises a chicken-or-egg question: Does the experience of living alone lead people to become depressed? Or are the depression-prone more likely to live alone because of their temperament, preference, or difficulty with relationships?
Both explanations are plausible, and both may play a role in any given situation, the researchers say.
Surveys of the study participants suggest that solo living may weaken social networks and produce "feelings of alienation from society" that could steer people toward depression, Pulkki-Råback says.
"People living alone were more cynical in their attitudes," she explains. "Being cynical and living alone may predispose to hopelessness and negative feelings, ultimately leading to depression."
On the other hand, she adds, "Cynical people may also have ended up living alone because they are difficult to deal with."
John Newcomer, M.D., a professor of psychiatry at the University of Miami Miller School of Medicine, says depression and feelings of isolation usually go hand in hand, and it's not always clear which comes first.
"Being depressed certainly can cause you to not only feel, but [also] become, more isolated," he says. "You feel hopeless that you're ever going to be able to have relationships, but even at another level, you...just don't feel like getting up and going out. You're undermotivated to do the various steps that are necessary to achieve social engagement."
At the beginning of the study, Pulkki-Råback and her colleagues interviewed each person about their living arrangements, work life, social background, and health. Roughly 15% of the participants reported living alone, and of those, slightly more than 40% cited divorce or widowhood as a reason.
Overall, 17% of the participants filled at least one antidepressant prescription during the study. The odds of doing so were 81% higher among people who lived alone, although that figure dropped as low as 64% depending on the various factors the researchers included in their analysis.
For instance, much of the heightened depression risk among women living alone was attributable to their tendency to have lower incomes, less education, and poorer housing conditions than their peers -- all of which could independently make depression more likely.
Similarly, among men, social and psychological factors such as work-related stress, a lack of social support, and heavy alcohol use explained some of the association between depression and living alone.
But these extenuating factors only accounted for about half of the increased risk, which suggests that living alone contributes to depression in other ways, Pulkki-Råback says.
Tina Walch, M.D., a psychiatrist at Zucker Hillside Hospital, in Glen Oaks, New York, says the interaction between a person's living situation and mental health is likely to involve a complicated mix of factors that are difficult to untangle in a single study.
"Any association between purchasing antidepressants and living alone is a little bit of a leap," Walch says. "It's multifactorial."
The study data did have some gaps that could have skewed the results. The authors weren't able to differentiate between people who preferred to live alone and those for whom the arrangement was not voluntary, for instance.
In addition, antidepressant prescriptions are an imperfect measure of depression rates. Prescription data doesn't capture people who are depressed but haven't sought professional help. And because the authors had no data on diagnoses, it's possible some of the study participants were taking the drugs for one of the many conditions besides depression for which they're prescribed, such as chronic pain, migraines, and insomnia.
Copyright Health Magazine 2011