In an article published in BJPsych Open, a study by Fleetwood and colleagues used Scottish administrative registers to show that not only have people with severe mental illnesses a profoundly reduced average life expectancy compared with the general population, but that the life expectancy gap had been further widening for those with schizophrenia and bipolar disorder over the past 20 years. This study has substantial clinical and public health importance, providing robust evidence to help in evaluation and planning of healthcare services in Scotland. Furthermore, this work raises important questions concerning the study of premature mortality in people with mental disorders per se, as well as the utility of administrative registers to study this phenomenon, which we highlight in this Editorial.