This week on the podcast, by request from an anonymous listener who wonders if her depressed partner might be bringing her down, Savvy Psychologist Dr. Ellen Hendriksen weighs in on whether or not depression is contagious. The answer might surprise you.
Is depression contagious? The short answer is: yes—it’s not called the common cold of mental illness for nothing.
But like most things, it’s complicated. Depression is contagious, but it’s not as if you get infected when your depressed friend cries on your shoulder. Instead, your own susceptibility or immunity depends on lots of things–your genetics, history, stress, and more.
It’s been known for almost a decade that both healthy and unhealthy behaviors are contagious—if your friends quit smoking or become obese, you’re more likely to do so, too. Even suicide can come in clusters.
Depression comes with its own set of unhealthy behaviors—pessimistic talk, criticizing self and others, cancelling social plans, getting into unhealthy sleeping and eating patterns, and generally being irritable or withdrawn. And it turns out that these behaviors—and the negative beliefs that drive them—can be communicated from person to person.
So roommates of depressed college students, children of depressed parents, and yes, for the listener who requested this episode, spouses of depressed partners also show comparable depressive symptoms.
And it’s not just the people you live with or see every day—emotions can be contagious within up to three degrees of separation. Better hope Kevin Bacon’s not depressed or all of Hollywood is going down.
Let’s look more closely at a study of college roommates that came out in 2014. Researchers studied over 100 pairs of newly assigned freshman roommates at move-in, and then again three and six months later. They examined, among other things, the students’ symptoms of depression and their tendency to ruminate—that is, their inclination to get tangled up in their own lousy feelings and to obsess about the causes and consequences of feeling bad.
Sure enough, freshmen who were paired with a roommate with a tendency to ruminate also picked up the tendency, which greatly increased their risk of depression. To be clear: depression symptoms themselves weren’t contagious, but thinking styles were. Freshmen who “caught” a ruminative style of thinking from their roommates had twice as many depressive symptoms after six months as those who didn’t pick up the thinking style.
Next, a 2015 study showed that depression can be made contagious under laboratory conditions, at least in rats. Researchers induced depression in rats by putting them through unpredictable, uncontrollable stressors over several weeks—a close approximation of chronic stress in people. For the rats, it meant things like keeping the lights on for 48 hours at a stretch and spilling water on their bedding—all probably better than being a pet in a kindergarten classroom, but still enough to make the rats depressed. For a rat, that doesn’t mean turning down invitations to Rats’ Night Out—it means an apathy to sugar water, a lab rat’s greatest pleasure. This is a marker of anhedonia—a hallmark symptom of depression in people and, apparently, rats.