Welsh J, et al. - The relationship between psychological distress and ischaemic heart disease (IHD) was examined, with consideration of confounding and undiagnosed disease. By confounding and functional limitations, a substantial part of the distress-IHD association was explained, an indicator of undiagnosed disease. Emphasis ought to be on psychological distress as a marker of healthcare need and IHD risk, rather than a causative factor.