The association between psychiatric disorders and cardiovascular disease is often reported in observational studies, but the question of reverse causation has always loomed large. In a linked research study (doi:10.1136/bmj.e4933), Russ and colleagues investigated the association between psychological distress and death from cardiovascular disease (recorded on death certificates) by examining data on more than 60 000 people from 10 large cohort studies based on the Health Surveys for England.1 The authors excluded early deaths (in the first five years of follow-up) and therefore the likelihood of reverse causation. Although the possibility of confounding can never be completely excluded, after adjusting for several “lifestyle” factors and cardiovascular disease risk factors, the authors still found a dose-response association between psychological distress and death from cardiovascular disease. These findings add to evidence that suggests a causal association between psychological distress and cardiovascular disease.

In the English health surveys used by Russ and colleagues, psychological distress was measured using the General Health Questionnaire (GHQ).2 This assessment of mental health status …