Mental health matters? An examination of how anxiety and depression influence the alcohol-e-cigarette use...

E-cigarette use has grown in popularity and is independently associated with alcohol use and mental health (anxiety/depression), but the interactions between alcohol and anxiety/depression with e-cigarette use have not been examined. We examined whether anxiety/depression would influence the association of both alcohol use frequency and heavy episodic drinking (HED) with e-cigarette use frequency, hypothesizing that alcohol use would be more strongly related to e-cigarette use among those with current anxiety/depression.

N = 11,006 adults (55 % female; 71 % non-Hispanic White, M age = 42) completed assessments of demographics, past 30-day e-cigarette and alcohol use, and current symptoms of anxiety and depression. Regression models including past 30-day e-cigarette users only (N = 2,395) examined the moderating effects of anxiety/depression (yes/no) on the alcohol-e-cigarette frequency relationship, examining alcohol use frequency and HED separately.

More than one-fifth (21.7 %) of the total sample reported any past 30-day e-cigarette use. Among e-cigarette users, past 30-day alcohol use frequency was associated with e-cigarette use frequency but did not significantly differ by mental health status (IRR = 1.02, 95 % 1.01, 1.02). HED was not associated with e-cigarette use frequency, regardless of mental health status (IRR = 1.02; 95 % CI: 0.93, 1.11).

The relationship between current alcohol use and e-cigarette use frequency was not statistically different between individuals who endorsed current anxiety and/or depression vs. those who did not. Findings support the need to consider other substance use within e-cigarette smoking prevention and cessation efforts. Additional longitudinal research is needed to infer directionality and causality.