An experimental study assessed the impact of positive versus negative mood inductions on health-related judgments with respect to both self-appraisal of health (present health status, future health risks, unrealistic optimism), and appraisal of unhealthy behaviours' noxiousness compared to an untreated control condition. With respect to self-appraisal of health it was hypothesized that there should be stronger effects of negative mood than of positive mood, but that there should also be a mood by specific judgment task interaction. With respect to unhealthy behaviours' noxiousness ratings it was assumed that positive mood leads to higher noxiousness ratings than negative mood.

The findings show that 23 per cent of the rating variances can be explained by the mood factor. In accord with the predictions self-appraisal of health was more negative under negative mood, but — with one exception — not more positive under positive mood than in the respective control condition. The exception relates to a measure of unrealistic optimism. Also in accord with the prediction positive mood led to higher noxiousness ratings of unhealthy behaviours than negative mood. All mood effects were independent of the respondents' sex, health locus of control and of the number of illness days during the previous year.

Under an applied perspective it is discussed how negative mood may exert a double detrimental influence on health care, whereas positive mood does not lead to a ‘happy go lucky’ attitude.