Vulnerability to depression can be contagious, study shows The research, published in the journal Clinical Psychological Science, follows up on studies showing that people who respond negatively to stressful life events, interpreting the events as the result of factors they can't change and as a reflection of their own deficiency, are more vulnerable to depression. The results revealed that students who were assigned to a room mate with high levels of cognitive vulnerability were likely to "catch" their room mate's cognitive style and develop higher levels of cognitive vulnerability. The reverse was also true and those assigned to room mates who had low initial levels of cognitive vulnerability experienced decreases in their own levels. The changes in cognitive vulnerability affected risk for future depressive symptoms, with students who showed an increase in cognitive vulnerability in the first three months of college having nearly twice the level of depressive symptoms at six months than those who didn't show such an increase. Dr Haeffel said it provided "striking evidence" for the contagion theory. He said: "Our findings suggest that it may be possible to use an individual's social environment as part of the intervention process, either as a supplement to existing cognitive interventions or possibly as a stand-alone intervention. Surrounding a person with others who exhibit an adaptive cognitive style should help to facilitate cognitive change in therapy. The research also suggests a new approach could be needed to cognitive vulnerability, he said. He explained: "Our study demonstrates that cognitive vulnerability has the potential to wax and wane over time depending on the social context. This means that cognitive vulnerability should be thought of as plastic rather than immutable.