Limitations
Our findings should be interpreted in the
context of our study’s limitations. The onset of
smoking might have preceded the onset of
mental disorders by many years. The time lag
between the onset of regular smoking and the
onset of new mental disorders may have
important implications. For example, participants
who have just started smoking may be
more vulnerable than those who have smoked
regularly for many years. A more detailed
assessment of the effect of smoking on onset of
mental disorders would require studying
a large cohort of participants recruited at an
early age and assessed at multiple time points
across the life span.
Smoking history and mental disorder symptoms
were both assessed by self-report and
were thus prone to recall bias. Past research has
shown that reports of lifetime mental disorders
are especially prone to such biases.60
In the context of these limitations, the data
provide supporting evidence from a large, longitudinal,
population-based survey on the link
between regular smoking and the onset of mental
disorders. These findings add to a growing literature
on the mental health consequences of smoking
and further suggest that these consequences
might be limited to the younger age group.
Conclusions
Past antismoking information and policy
initiatives were mostly motivated by findings of
increased risk of lung cancer and cardiovascular
disease and higher rates of mortality among
smokers.61 Our findings and results from other
studies of the mental health consequences of
smoking for youths15,21 point to an increased,
smoking-attributable burden of mental health
morbidity and impairment in functioning. It is
estimated that by 2030, major depression will
be the number one contributor to the burden
of disease worldwide.62 The finding of links
between smoking and major depression as well
as other common and disabling mental disorders
highlights the urgency of antismoking
campaigns and policy initiatives, especially
those targeting adolescents and young adults.
Our finding of a strong association between
state-level public attitudes and smoking behavior
highlights the role of public health
education campaigns and media in shaping
behaviors. The observed association with state
cigarette taxes highlights the role of policy initiatives
and financial disincentives in discouraging
smoking behavior. Public health interventions
involving education and financial disincentives
may be combined with individual-level smoking
cessation interventions for youths63---66 to effectively
reduce smoking behavior among this vulnerable
population group