**5. Happiness**

Negative emotional states (e.g., depression, anxiety) are proven risk factors for cardiovascular disease; however, much less is known about the association between positive emotional states (e.g., happiness and optimism) and cardiovascular health. Steptoe et al. have suggested that positive emotions may have direct and beneficial effects on physiological processes including those involving the neuroendocrine, inflammatory, immunological and cardiovascular sys‐ tems [38]. The association between positive psychological well-being and mortality could be mediated in part via behavioural pathways. For example positive dispositions are related to predictors of prolonged survival, such as not smoking, exercising regularly, reduced alcohol consumption, and better sleep quality. Psychologically balanced persons might have increased adherence to medical regimens because inverse associations between adherence and depres‐ sion have been described. However, the protective effect of positive emotions on mortality in healthy population studies persisted even after fully controlling for behavioural covariates, suggesting that other pathways may also be involved. Direct physiological pathways might also contribute to associations. Positive psychological well-being could alter people's disease susceptibility via the attenuation of sympathetic nervous system activity and the enhancement ofparasympatheticactivation.Positiveaffectsmayreducestress-inducedelevationsofinflamma‐ toryandcoagulationfactors,suchasfibrinogenandinterleukin-6,whicharecrucialincardiovas‐ culardisease,andreducevulnerabilitytoinfectiousillness.Positivepsychologicalwell-beingwas associated with reduced cardiovascular mortality in healthy population studies, with a near significant effect in patients with established cardiovascular disease [39]. In one of prospective epidemiological cohort studies participants with greater emotional vitality were at markedly reduced risk for CHD, and this effect remained significant after controlling for medical and psychosocial factors [40]. Optimism was associated with recovery from CABG surgery within 6 months [41]. Post hoc analysis of previous data showed that among depressed post-CABG patients, optimists responded to depression treatment at higher rates. Independent of depres‐ sion, optimists were less likely to be rehospitalized by 8 months after CABG [42].
