Vaping and Mental Health.

"Vaping" refers to the inhalation of aerosols produced in devices that heat liquid solutions. The aerosols may contain various additives, flavours, nicotine and other drugs such as cannabis. Nicotine is the most common psychoactive substance in vaping devices (or e-cigarettes) in Canada. While vaping has been viewed primarily as a cessation method or harm reduction strategy for smokers of combustible tobacco cigarettes, a new pattern is becoming evident in adolescents and youth (age 15-24) in Canada. In this age group, vaping is reported in increasing frequencies among those who have never smoked. This suggests the possible emergence of a de novo pattern of substance use and suggests the emergence of an unmet treatment need, vaping cessation. The mental health implications of vaping are largely unknown but available data suggest that vaping is associated with mental health changes similar to those seen with combustible tobacco cigarettes. Understanding the mental health impact of "vaping" will be challenging and research is needed. An important message from the smoking literature is that data from randomized cessation trials may be especially valuable because of complex issues of temporality and confounding connected to observational data.