Mental illness is often associated with comorbid health problems. Two important ‘comorbidities’ of mental illness, given their driving role in decreasing quality and duration of life, are substance (mis)use and cardiovascular disease. Whether these comorbidities arise due to causal pathways, and if so, in which direction, is poorly understood.
Aim
The Comorbidity and Causality research line brings together sophisticated epidemiological and genetic methods with the aim of fully unraveling the (causal) nature of relationships between mental illness and its comorbidities. This research line is currently funded by an ERC Starting grant (‘UNRAVEL-CAUSALITY’, 101076686) and a Senior Scientist Dekker grant (Dutch Heart Foundation, 03-004-2022-0055).
Studies
Key methods that we apply: Mendelian randomization analysis, polygenic score analysis, (twin-)family designs, (genomic/transcriptome-wide) structural equation modelling, etc. Datasets that we use: Lifelines, UK Biobank, Helius, NESDA, Generation R, Netherlands Twin Register, etc. Examples of specific comorbidities that we investigate: (e-)smoking & mental illness, smoking & brain imaging outcomes, smoking & stress/anxiety, depression & cardiovascular disease, PTSD & cardiovascular disease, schizophrenia & arrhythmic disorders, physical activity & mental health disorders, etc.
Throughout the research line we apply ‘triangulation’; the deliberate combination and integration of multiple methods in one study, in order to obtain more robust and reliable (causal) evidence. Apart from applying triangulation, we also work on improving the process of triangulation itself, by developing frameworks and more systematic (quantitative) approaches.
Translation
A sounding board of stakeholders (including experts by experience and clinicians) has been established and regular meetings are conducted to discuss aims, results, and implications of our findings. Visual summaries and infographics will be developed to facilitate knowledge transfer and improve prevention and treatment. Finally, a randomized online experiment will be conducted to test how informing medical doctors about the causal nature of specific comorbidities influences clinical views and decisions.
