Smoking and mental health - NCSCT

Neurobiological and behavioural mechanisms linking smoking and mental disorders 3
withdrawal symptoms, and a subsequent meta-analysis confirmed this
conclusion. 86 However, interesting interactions between nicotine and other
variables on mood including psychiatric diagnosis and subclinical affective
syndromes have been reported. In a series of small laboratory studies that
included people with major depression, Salin-Pascual and colleagues 87–89 found
that a moderate-strength nicotine patch applied for several days improved mood
relative to placebo patch in both depressed and non-depressed non-smokers. As
non-smokers were tested, the effect cannot be attributed to reversal of the
nicotine withdrawal syndrome. In a more recent investigation with non-smokers
with major depression, Cox and colleagues 90 found improvements in mood
among participants in both the nicotine and placebo patch condition.
McClernon and colleagues 91 found that a nicotine patch worn for 4 weeks by
subclinically depressed non-smoking participants improved mood over the first 3
weeks of the trial, whereas participants assigned to the placebo patch condition
did not report any improvements in mood. 92
In a study of non-smoking adults with attention deficit hyperactivity disorder
(ADHD), nicotine (but not placebo) decreased depression scores after 15 days of
administration. 93 In a field study using real-time data collection, Jamner and
colleagues 94 found that both smokers and non-smokers high in trait hostility
(assessed at baseline) reported lower levels of angry mood and greater wellbeing
when wearing a nicotine patch but not when wearing a placebo patch. Nonsmokers
reported that angry mood was experienced for 23% of a day in which
they wore a placebo patch, compared with 14% when using a nicotine patch; for
smokers the proportions were 55% and 32% respectively. In a laboratory study,
Kassel and Unrod 95 found support for their hypothesis that smoking has a
calming or stress-relieving effect only (or especially) among highly anxious
smokers and only in combination with a stimulus that distracts them from the
source of stress. Taken together, although limited in number, these studies
suggest that the mood effects of nicotine may be more apparent in psychiatrically
impaired subgroups of smokers, including under stressful and other conditions.
Studies of negative affect as a risk factor for tobacco use have also investigated
additional risk factors. Adolescents with negative affect or anxiety are more likely
to associate with peers who smoke, 96–99 which in turn predicts smoking
initiation and progression to regular use. 100 Adolescents with higher levels of
depression may also be more sensitive to peer behaviour, more likely to select
non-conventional peers or both. 96 Parental attachment problems (including poor
communication and trust between parents and offspring) and adverse childhood
events (such as socioeconomic disadvantage or physical abuse), as reported by
adolescents, are also associated with increased risks of both depressive symptoms
and tobacco use. 97
Prospective studies of the temporal association between depressive affect and
both smoking initiation and progression to regular tobacco use indicate that
depressive affect precedes smoking initiation, although the evidence is somewhat
mixed, and the relationship may be bidirectional, 101 eg Audrain-McGovern and
© Royal College of Physicians 2013 45