Abstract
Since the introduction of vaping devices to the marketplace, the number of vape users has continued to rise annually. Young adults, ages 18 to 25 years old, are using vapes at increasing levels. Furthermore, there are concerns that young adults are taking up vaping without ever having smoked cigarettes, which presents the potential for a new generation of young adults to develop nicotine dependence. Whilst research is ongoing regarding the short-term and long-term health effects of vaping, research is beginning to explore how and why young adults are choosing to engage with vaping products. Although prior research has focused on temporal trends, and demographic and health characteristics of young adults who vape, much less research has considered the role of psychological factors in vaping behaviours.
The goal of this thesis was to explore the psychological characteristics of young adults who vape, with the overarching aim to identify how psychological factors may influence vaping behaviours and susceptibility to vaping. The thesis focused on two broad types of psychological factors – mental health vulnerabilities and personality traits – given the importance of these factors in predicting other types of substance use, including cigarette smoking. Three methodological approaches were used throughout the thesis – cross sectional correlational research (Studies 1 and 2), daily diary research (Study 3), and qualitative research (Study 4). Study 1 was an exploratory cross-sectional correlational survey design of 521 young adults from the United States that utilised independent logistic regressions (ILR) and multiple logistic regressions (MLR) to explore the demographic and psychological predictors of self-reported vaping in young adults. Vaping was defined using three self-reported outcome measures (ever-use, current use, and susceptibility). Study 2 was a replication of Study 1 using a confirmatory cross-sectional correlational survey design of 1,025 young adults from the United States, United Kingdom, and New Zealand. Study 2 also used ILR and MLR to investigate the demographic and psychological predictors of vaping in young adults. Study 3 was a daily diary study of 225 young adults from New Zealand that aimed to replicate the findings from Study 1 and 2, as well as investigate within-person variations in vaping as a function of day-level factors of drinking and mood. Study 4 was a qualitative focus group study of 28 young adults from New Zealand designed to explore their views and perceptions of vaping and the characteristics of those who vape. Qualitative data were analysed using Reflexive Thematic Analysis.
This thesis yielded three broad findings. First, it found that lower conscientiousness was the single strongest psychological predictor of vaping and vaping susceptibility among young adults. This pattern was replicated across all three quantitative studies, suggesting that lower conscientiousness is a key personality trait among young adults who vape. Second, mental health vulnerabilities were not a consistent predictor of vaping across studies. Whilst Study 1 found that people with higher stress were more likely to be current vapers, Study 2 found no link between mental health vulnerabilities and vaping likelihood and Study 3 found that vaping was more prevalent on days when people reported better mood, Third, whilst individual characteristics were robust predictors of vaping in the quantitative studies, the qualitative study yielded themes suggesting that social and environmental factors were becoming important influences on vaping in young adults.
In conclusion, this thesis provides insights into the psychological factors that may play a role in young adults’ vaping. Overall, results suggest that young adults with poorer impulse control may need additional support to prevent the uptake of vaping. A focus of future research should be on how social and environmental factors also contribute to vaping uptake in addition to individual psychological factors.