"Shotgunning" in a population of patients with severe mental illness and comorbid substance use disorders.

"Shotgunning" refers to the practice of one individual forcibly exhaling smoke into the mouth of another, and may increase the risk of transmission of respiratory pathogens. The extent of shotgunning among individuals with co-occurring serious mental illness and substance use is unknown. We included questions about shotgunning in an interview of 236 participants of a study testing a model to prevent and treat HIV and hepatitis. Shotgunning was common (61% [145/236]) and correlated with increased substance use severity and several high-risk behaviors. Only 8% (11/145) understood that shotgunning could transmit disease. Further research and patient education on shotgunning is warranted.