The Role of Companionship and Conflict in Perceptions of a Friend's Heavy Alcohol and Marijuana Use.

Individuals have been found to "project" their own substance use onto perceptions of their friends' substance use. This study explores whether companionship and conflict relate to incorrect perceptions of a friend's heavy alcohol and marijuana use after controlling for the behavior of the respondent and friend. Mixed models demonstrate that having higher levels of companionship, but not conflict, with a friend result in significantly higher perceptual levels of the friend's heavy alcohol and marijuana use. While beneficial for the friendship, higher levels of companionship may result in a person overestimating the heavy alcohol and marijuana use of a friend.