Smoking uptake is associated with increased psychological distress: results of a national longitudinal study.

BACKGROUND There is evidence that smoking is associated with poorer mental health. However, the underlying mechanisms for this remain unclear. We used longitudinal data to assess whether smoking uptake, or failed quit attempts, are associated with increased psychological distress. METHODS Data were used from Waves 3 (2004/05), 5 (2006/07) and 7 (2008/09) of the longitudinal New Zealand Survey of Family, Income and Employment. Fixed-effects linear regression analyses were performed to model the impact of changes in smoking status and quit status (exposure variables) on changes in psychological distress (Kessler 10 (K10)). RESULTS After adjusting for time-varying demographic and socioeconomic covariates, smoking uptake was associated with an increase in psychological distress (K10: 0.22, 95% CI 0.01 to 0.43). The associations around quitting and distress were in the expected directions, but were not statistically significant. That is, smokers who successfully quit between waves had no meaningful change in psychological distress (K10: -0.05, 95% CI -0.34 to 0.23), whereas those who tried but failed to quit, experienced an increase in psychological distress (K10: 0.18, 95% CI -0.05 to 0.40). CONCLUSIONS The findings provide some support for a modest association between smoking uptake and a subsequent increase in psychological distress, but more research is needed before such information is considered for inclusion in public health messages.