Humans share everything from food to love to sickness. But recent studies show that mental issues can also be a shared experience. College roommates typically live in a microcosm that includes tight living environments. Campus dorms don\u2019t leave much wiggle room and roommates get to know each other extremely well. But for some co-eds dealing with depression, their malady can rub off on their bunkmate. Researchers from the University of Notre Dame looked at the living situations of more than 200 individuals on campus, all of whom were freshmen. An online questionnaire established which of the roommates was susceptible to depression. The questionnaire also measured the roommates\u2019 cognitive vulnerability. These questions were asked within the first month of the semester. People who interpret stressful life events as the result of factors they can\u2019t change and as a reflection of their own deficiency are more vulnerable to depression. This \u201ccognitive vulnerability\u201d has been shown to be such a potent risk factor for depression that it can predict who is likely to experience a depressive episode in the future, even if they have never been depressed before. Questions were also asked at three-month and six-month intervals. Interestingly, even the students with low levels of cognitive vulnerability with roommates that had fallen into a depression had developed similar symptoms. In most cases, the behavior of one roommate that has a style of thinking that makes one more vulnerable to depression is adopted by the other roommate. The results have led researchers to believe that there is a \u201ccontagion effect.\u201d But it also gives researchers an idea on how to more effectively treat depression, especially if the contagion effect can be harnessed in one way or another. It is not uncommon for entire families to fall into a similar pattern of depression as it leaps from one member to the next. In such situations, behavior leans toward isolation from each other, or when interaction does occur, it\u2019s in the form of sarcastic tones or negative speech.