In their report of corticosteroid trials in hyperemesis gravidarum, Nelson-Piercy et al. display the classic Cartesian mind–body dualism that dogs so much biomedical research. In accounting for their failure to achieve a statistically significant result, they suggest that a disproportionate number of their participants were ‘vomiting for emotional reasons’, a group apparently distinct from those with a hormonal aetiology to their condition. Such a simplistic division into two discrete nosological categories, although methodologically convenient, belies the complex interactions among biological, psychological and social factors underlying hyperemesis gravidarum.

The findings of this trial are illustrative of the inadequacy of a purely pharmacological approach to this condition, rooted as it is in a narrow biomedical conceptual framework. It is time that the complexity of this condition was recognised, and a biopsychosocial perspective was taken in its management—one that recognises the centrality of ‘emotional reasons’ in its causation, rather than dismisses them as confounding variables.