Thesis explores how shared genetics could lead to more personalized care for severe mental illnesses
Severe mental illnesses, such as schizophrenia, bipolar disorder and anorexia nervosa, are long-term conditions that can have a major impact on people's daily lives. Despite decades of research, there are no reliable biological markers that can be used to diagnose these conditions, and treatment options do not work equally well for everyone. This is partly because researchers still do not fully understand the biological mechanisms behind them.
In a new thesis from Karolinska Institutet, Zheng-An Lu explored new ways to improve our understanding of severe mental illnesses (SMIs). By studying genetic factors that SMIs share with other common health conditions, she identified promising leads for new biomarkers and treatment targets.
What have you done in your studies?
"I studied genetic factors that severe mental illnesses share with other psychiatric and physical health conditions. Using large-scale genetic data, I explored why these disorders often occur together and what biological mechanisms might explain these links. I examined the shared genetics across SMIs as well as between SMIs and some other conditions, such as asthma and impaired lung function.“
““By studying genetic factors that are shared across severe mental illnesses and related conditions, we identified more genetic variants linked to these disorders," says Zheng-An Lu, doctoral student at the Department of Medical Epidemiology and Biostatistics, KI.
“We also found clues about the biological processes and tissue-specific genetic markers that may play a role in their development. These findings could help researchers discover new biomarkers and potential treatment targets. And we found that shared genetic factors may help explain why people with severe mental illnesses can have different symptoms and respond differently to treatment. In the future, these insights could support more personalized care, helping clinicians tailor treatments to the needs of each patient.”
Why did you become interested in this topic?
“The development of precision medicine approaches towards severe mental illnesses is relatively slow due to difficult access to biological data. A genetic approach that studies several diseases together can use information from related conditions to find more genetic markers and improve predictions of severe mental illnesses, which could benefit both patients and clinicians.”
What do you think should be done in future health care and research?
“Future research should combine genetic information with other types of biological data, such as measurements of proteins and gene activity, as well as brain imaging data. Using advanced analytical methods, including machine learning, could improve our understanding of severe mental illnesses and help predict who is at risk of developing them or experiencing certain outcomes. It will also be important to test these approaches in different populations and for other related health conditions."
Doctoral thesis
”Genetic overlap between severe mental illnesses and their comorbidities”. Zheng-An Lu, September 2026.
Facts about doctoral theses
A doctoral thesis is the final written product of a postgraduate education, which in Sweden corresponds to four years of full-time studies. It varies between different disciplines how a doctoral thesis is structured. In the field of medicine, the doctoral student usually collects three to five scientific articles and presents them together with a thesis summary or overview, a so-called ‘kappa’ (literally meaning overcoat in Swedish).
After the doctoral student has passed the public defence of the thesis, he or she receives a doctoral degree (also called a PhD), which is the highest possible educational degree in Sweden. Karolinska Institutet has approximately 2,000 active doctoral students and each year approximately 350 doctoral theses are published at our university.