The new issue of *British Medical Journal* that was recently published (Vol
337, No 7660, July 5 2008 ) includes a study: “Positive and negative affect
and risk of coronary heart disease: Whitehall II prospective cohort study.”

The authors are Hermann Nabi, Mika Kivimaki, Roberto De Vogli, Michael G
Marmot, & Archana Singh-Manoux.

Here’s how the article begins:

[begin excerpt]

Smoking, hypertension, hypercholesterolaemia, and diabetes are
established risk factors for coronary heart disease, a leading cause of
morbidity and mortality in Western industrialised countries.1 2 However,
psychological factors, such as emotions, may also have a role in the
development of coronary heart disease.3 4 Several prospective studies
have found anxiety, hostility/anger, and depression to be associated
with an increased risk of coronary heart disease in healthy participants.
3 5 As the relative importance of these three negative emotions on risk
of coronary heart disease remains largely undefined,6 7 they have been
hypothesised to be the components of a single underlying factor,
labelled negative affect. Negative affect refers to “stable and
pervasive individual differences in mood and self-concept characterised
by a general disposition to experience a variety of aversive emotional
states.”5 8 High negative affect has been described as a general
tendency to report “distress, discomfort, dissatisfaction, and feelings
of hopelessness over time and regardless of the situation,” and low
negative affect is characterised by “calmness and serenity.”8 9
Supporting this conceptualisation, a considerable neurobiological and
psychological overlap between anxiety, hostility/anger, and depression
has previously been shown.10 11

As attempts to link psychological factors to heart disease have focused
on negative emotions, mostly depression,7 whether positive emotions
might also have a role in the development of coronary heart disease
remains unclear. Research suggests that positive affect and negative
affect are two independent systems and that positive affect is not
simply the opposite of negative affect or an absence of negative affect.
9 12 High positive affect refers to a general tendency to experience a
“state of high energy, full concentration, and pleasurable engagement,”
whereas low positive affect is characterised by “sadness and lethargy.”8
9 Distinct neural networks may exist to regulate positive and negative
emotions; dopamine metabolism may be associated with positive affect and
serotonin with negative affect,13 14 supporting the assertion of the
independence of the two types of affect.

We are aware of no previous large scale prospective studies on the
independent effects of negative and positive affect on coronary heart
disease. A six year follow-up of 2478 older participants in North
Carolina found that positive affect was associated with decreased risk
of stroke, but it did not examine coronary heart disease as an outcome,
and the assessment of negative affect was limited to depressive symptoms.
13 In this report from the Whitehall II study, we examine the
independent associations of both negative affect and positive affect
with subsequent coronary heart disease after taking account of
established risk factors among participants followed up over 12 years.
In addition, we examine whether the balance between positive and
negative affect is associated with subsequent coronary heart disease.

[end excerpt]

Here’s how the article ends: “Data from a large occupational cohort
provide no evidence for associations between positive affect or affect
balance and coronary heart disease in men and women who were free of
diagnosed coronary heart disease at recruitment to the study. However,
we found negative affect to be weakly predictive of incident coronary
heart disease events, independently of sociodemographic characteristics,
conventional risk factors, and job strain. Further research is needed to
examine whether our findings are generalisable to other populations as
well as to disentangle the potential pathways that may link negative
affect to coronary heart disease.”

The author note states that correspondence about the article may be sent
to: Hermann Nabi, Department of Epidemiology and Public Health,
University College London, London WC1E 6BT, <H.Nabi@public->.