Psychological distress and ischaemic heart disease: cause or consequence? Evidence from a large prospective cohort study

Background Ischaemic heart disease (IHD) incidence is elevated in people reporting psychological distress. The extent to which this relationship is causal or related to reverse causality—that is, undiagnosed disease causing distress—is unclear. We quantified the relationship between psychological distress and IHD, with consideration of confounding and undiagnosed disease. Methods Questionnaire data (2006–2009) from 151 811 cardiovascular disease-free and cancer-free Australian general population members aged ≥45years (45 and Up Study) were linked to hospitalisation and mortality data, to December 2013. A two-stage approach estimated HRs for incident IHD (IHD-related hospitalisation or death) for low (Kessler-10 scores: 10–<12), mild (12–<16), moderate (16–