03/05/2013 03:48 pm ET Updated May 05, 2013

Freshman Funk: Is Harmful Thinking Contagious?

I know very few people who would describe first semester, freshman year of college, as a time of unqualified joy. I was certainly ready to leave home, but even so it was a disruptive time. I was disconnected from my family and close friends for the first time and, even more difficult, thrown into a dormitory full of strangers -- young men from unfamiliar places with diverse experiences and values.

This social disruption was not an altogether bad thing in the long run. I knew nothing about anything when I arrived on campus, and these new classmates, including my roommate, opened my mind to all sorts of ideas I might not have encountered otherwise. The intellectual life was contagious.

Ideas may not have been the only thing that was contagious, as it turns out. New research is now suggesting that college freshmen may influence each other in much more fundamental ways. Indeed, people who share a tumultuous social world -- even if they are thrown together randomly -- may shape one another's basic thinking style, and as a consequence influence one another's mental health in important and lasting ways.

University of Notre Dame psychological scientist Gerald Haeffel and his colleagues have been exploring what's called cognitive vulnerability -- a way of thinking, and interpreting life's travails, that predisposes people to clinical depression. It's long been thought that cognitive style is fairly well fixed by adolescence. Some of us are blessed, while others are saddled with a tendency toward negativity and rumination and other cognitive precursors of melancholy. But there is reason to believe that cognitive style is not immutable. Haeffel had the idea that in certain unique environments, this stable trait becomes less stable, more subject to change. Specifically, the way we think about life may be altered during life transitions, when our social milieu undergoes dramatic change. The freshman experience is a perfect example of such a disruptive transition.

The freshman dorm also offers a natural experiment of sorts. Not only are freshmen going through a major life transition, they are also at the peak age for developing depression. What's more, they are randomly assigned to roommates, eliminating any selection bias that might skew the results. Haeffel wanted to see if, in this naturally occurring social world, a risky cognitive style might "rub off" on others who are initially less at risk. In other words, is the cognitive predisposition for depression "catching" in a freshman dorm?

Haeffel recruited more than a hundred roommate pairs who were randomly assigned to their dorms and roommates, and gave them a battery of tests. These included two well regarded measures of cognitive vulnerability and a depression inventory -- both completed within a month of arriving on campus. The freshmen completed these measures again three months later and six months later -- at which times they also completed a questionnaire about recent stressful life events. The idea was to see if any of the volunteers' cognitive style changed over time, becoming more like the roommates' style -- and if this shift led in turn to actual symptoms of depression.

The results were clear and provocative. As reported in a forthcoming issue of the journal Clinical Psychological Science, cognitive style was indeed contagious. A student's level of cognitive vulnerability at three and six months was significantly affected by his or her roommate's initial level of vulnerability, and vice versa. Specifically, those who chanced upon a roommate with high vulnerability -- these unfortunate freshmen were likely to "catch" their roommate's cognitive style. On the other hand, those lucky enough to land with a less vulnerable roommate lowered their own cognitive vulnerability. Perhaps most important were the downstream consequences: Freshmen who experienced a jump in cognitive vulnerability during the first three months of college -- who caught this thinking style from their roommate -- had nearly twice the symptoms of depression at six months.

Three months is a very short time to see such a dramatic change in thinking style -- a trait previously considered stable for life. This suggests to Haeffel that this contagion effect may not be restricted to major life transitions, like heading off to college. In fact, Haeffel now believes that the same phenomenon may be at work in today's more ubiquitous social media network. With the modern social environment no longer restricted to immediate surroundings, and much more in flux, it's possible that people's cognitive vulnerability for depression may also be in a perpetual state of flux.

Wray Herbert's blogs--"We're Only Human" and "Full Frontal Psychology"--appear regularly in The Huffington Post.