The doctoral dissertation in the field of Biology will be examined at the Faculty of Health Sciences at Kuopio Campus. The public examination will be streamed online.
What is the topic of your doctoral research? Why is it important to study the topic?
My thesis explores how plasma proteomics can be used to identify molecular signatures of mental health susceptibility in adolescents and young adults, by linking circulating proteins to measures of mental health susceptibility, including sex-specific patterns. Mental health problems tend to start before adulthood, but current diagnostics methods rely on questionnaires and clinical interviews, which can be subjective, are hard to scale, and often miss at-risk young people. Blood-based tests such as plasma proteomics could help detect vulnerability before the development of disorders. Understanding how these protein signatures relate to mental health risk is important to the understanding of early development of mental health issues, and is a necessary step toward earlier, more precise, and ethically informed diagnostic strategies in youth.
What are the key findings or observations of your doctoral research?
- Plasma protein profiles are associated with mental health risk scores across two distinct cohorts (WALNUTs cohort in Spain and FinnTwin-12 study in Finland).
- In adolescents, high scores in the Strengths and Difficulties ( SDQ) questionnaire relate to proteins involved in complement and coagulation, immune signalling, lipid transport and neuronal remodelling.
- Convergent patterns across cohorts suggest possible shared systemic biology underlying general psychopathology risk.
This research directly links widely used mental health measures (e.g. SDQ scores) with unbiased DIA LC–MS/MS plasma proteomics in population-based cohorts. It demonstrates that psychological risk is associated with plasma signatures, supporting the idea of blood-based markers for mental health vulnerability. It provides a detailed sex-specific plasma proteome investigation of adolescent mental health risk, highlighting the need for sex-aware biomarker panels.
How can the results of your doctoral research be utilised in practice?
The results add to the fundamental understanding of early mental health vulnerability in youth and can be used in several ways. The identified protein panels and pathways offer candidates for multi-protein biomarkers that could complement questionnaire-based screening. In the long term, such panels could support earlier and more objective identification of high-risk adolescents and young adults in primary care, school health services, or cohort-based follow-up, especially when combined with existing tools such as the SDQ. Specific proteins and pathways, were shown as plausible links between blood plasma and mental health risk, providing concrete targets for follow-up work on longitudinal cohorts. Overall, the thesis advances the field toward multi-protein, sex-aware biomarker models for early mental health risk that can be further validated and eventually adapted for use in clinical and public health settings, provided that ethical, practical and equity aspects are addressed.
What are the key research methods and materials used in your doctoral research?
The research is based on two human population cohorts: the WALNUTs cohort of healthy school children and the FinnTwin-12 cohort of young adult twins. In WALNUTs, mental health risk was assessed using the SDQ. In FinnTwin-12, the p-factor summarising general psychopathology was used. Proteomic analyses were performed using DIA-based LC–MS/MS. Advanced bioinformatics methods were utilised for the data analysis, including drift and batch correction, and statistical modelling. Linear models were used to test associations between the protein abundances and mental health risk indicators. Compact multivariable models were trained to distinguish individuals with raised vs low SDQ scores, highlighting the utility of protein panels as classifiers rather than single biomarkers. Significant protein sets were subjected to Gene Ontology and pathway enrichment and protein–protein interaction network analysis (STRINGdb).
The doctoral dissertation of Aleksei Afonin, MSc, entitled Proteomic signatures of mental health susceptibility in youth plasma will be examined at the Faculty of Health Sciences. The Opponent in the public examination will be Dr Jane English of the University of Cork, Ireland, and the Custos will be Professor Katja Kanninen of the University of Eastern Finland. The public examination will be held in English.
