All three aims of FundaMentalHM have already been fulfilled. For aim 1, we carried out a comprehensive study investigating the association between all mental disorders and a broad range of medical conditions. This study has been performed in collaboration with my colleague Dr Natalie Momen and has been published in the New England Journal of Medicine. We used data from 5.9 million Danish residents who were followed from 2000 to 2016. Using national registers, we observed that most mental disorders were associated with an increased risk of a subsequent medical condition, and risks varied according to the time since the diagnosis of the mental disorders. Additionally, together with PhD student Nanna Weye, we have estimated register-based years lived with disability associated with mental disorders for the entire Danish population, in a paper that is published in Lancet Psychiatry. For aim 2, we carried out a study investigating the association between all mental disorders and excess mortality. I have been the main author of the paper, which was published in The Lancet. We used data from 7.2 million Danish residents from 1995 to 2015, and we observed that all mental disorders were associated with a reduction in life expectancy, for both men and women (on average 10 years in men and 7 years in women). Additionally, we wrote a research letter to JAMA Psychiatry investigating time trends in life expectancy gap for those with mental disorders. Combining aims 1 and 2, we have performed several studies (that were not originally planned in my grant proposal) looking at the association between comorbid conditions and later mortality (Plana-Ripoll et al. World Psychiatry 2020; Momen et al JAMA Psychiatry 2022. For aim 3, we have created two new health metrics that can be applied for a better understanding of disease burden. For the mortality papers, we used a new metric to estimate life expectancy that overcomes some of the limitations of the metrics used in the past (for example we were able to use the observed age of onset, instead of a fixed age of onset). In order to make this new methodology available to a broader range of researchers, I developed a statistical package that is freely available. Additionally, we wrote a tutorial that was published open access in Plos One. We have now applied this metric to 1,800 different health conditions (Plana-Ripoll et al. PLOS Medicine 2022). For comorbidity, we have developed an informative metric (Weye et al. Lancet Psychiatry 2021) that estimates the contribution of (i) an index disorder (e.g. depression), and (ii) comorbid mental and other medical conditions (e.g. alcohol use disorders, diabetes). This measure shows never-before-seen details of the impact of comorbidity on disability.
