BackgroundSleep, physical activity, and diet have been associated with mental health and well-being individually in young adults. However, which of these “big three” health behaviors most strongly predicts mental health and well-being, and their higher-order relationships in predictive models, is less known. This study investigated the differential and higher-order associations between sleep, physical activity, and dietary factors as predictors of mental health and well-being in young adults.MethodIn a cross-sectional survey design, 1,111 young adults ages 18–25 from New Zealand and the (...) United States answered an online survey measuring typical sleep quantity and quality; physical activity; and consumption of raw and processed fruit and vegetables, fast food, sweets, and soda, along with extensive covariates and the outcome measures of depressive symptoms [measured by the Center for Epidemiological Depression Scale ] and well-being.ResultsControlling for covariates, sleep quality was the strongest predictor of depressive symptoms and well-being, followed by sleep quantity and physical activity. Only one dietary factor—raw fruit and vegetable consumption—predicted greater well-being but not depressive symptoms when controlling for covariates. There were some higher-order interactions among health behaviors in predicting the outcomes, but these did not survive cross-validation.ConclusionSleep quality is an important predictor of mental health and well-being in young adults, whereas physical activity and diet are secondary but still significant factors. Although strictly correlational, these patterns suggest that future interventions could prioritize sleep quality to maximize mental health and well-being in young adults. (shrink)

BackgroundThe use of electronic nicotine delivery systems, also known as vaping, is becoming popular among young adults. Few studies have explored the psychological factors that predict ENDS use and susceptibility in young adults, in addition to known demographic predictors.MethodIn a cross-sectional survey design, 521 young adults, ages 18–25 from the United States, were recruited via Amazon’s Mechanical Turk in 2019, to answer an online survey measuring demographic characteristics and psychological characteristics related to mental health and the Big Five personality traits. (...) The survey also included measures of ENDS ever-use, current use, and susceptibility, which we predicted from the demographic and psychological measures using independent and multiple binary logistic regression analyses.ResultsOf those surveyed, 282 were ENDS ever-users, 93 were current ENDS users, and 61 were ENDS susceptible; 62 were current smokers. Demographically, young adults lower in adulthood socioeconomic-status, not pursuing education further than high school, and current smokers were more likely to be ENDS users. Psychologically, young adults higher in anxiety and lower in conscientiousness more likely to have ever-used ENDS. Lower conscientiousness further predicted current ENDS use and ENDS susceptibility.ConclusionIn this sample of MTurk workers, young adults with experience in vaping were more demographically and psychologically vulnerable than young adults with no experience in vaping. Young adults interested in vaping, but without prior experience, were less conscientious than their non-interested peers. Interventions to target vaping use should focus on economically disadvantaged young adults and those lower in conscientiousness. (shrink)