Contagion of suicidal symptoms as a function of assortative relating and shared relationship stress in college roommates.

Vulnerable people may become socially contiguous via assortative relating, and thus simultaneously susceptible to the effects of shared life stress. To test this possibility, 138 undergraduates and their roommates completed questionnaires on suicidality and stress. Consistent with an assortative relating process, roommates who chose to room together were more similar on a suicide index than were roommates who were assigned to room together. Stress in the roommate relationship amplified similarity in roommates' suicide levels. Results were consistent with the view that shared stress simultaneously affects the suicidality of people whose contiguity was pre-arranged by an assortative relating process.