We are back with our 'In Conversation' series! In this post, meet Christina Steyn a PhD student on the Wellcome Trust Translational Neuroscience programme, with a keen interest in uncovering the biological basis of psychiatric disorders.

Please share a little about yourself.

My name is Christina Steyn. I am from South Africa and came to Edinburgh in September 2023. I spent the first year of my PhD doing three different rotation projects (working with zebrafish, high performance computers, and human brain organoids). I am currently in the first year of my PhD under the supervision of Prof Danny Smith and Dr Katie Marwick.

Tell us a bit more about your current work.

My project focuses on investigating the relationship between metabolic health and psychiatric illness such as depression, bipolar disorder, and schizophrenia. This is a developing area of psychiatry which has been gaining traction due to the high comorbidity observed between metabolic disorders and mental illness. Instead of the traditional approach of treating physical and mental health conditions as distinct problems, clinicians are slowly moving towards treating these as interrelated problems. There are three main questions that I am looking to address:

1. Can I identify metabolic biomarkers that are predictive of clinical outcomes in patients suffering from severe mental illness?

2. Are there differences between men and women with regards to metabolic risk factors for mental illness?

3. Does sleep influence any observed relationship between metabolite levels and clinical outcomes of psychiatric illness?

To address these questions, my work will involve two approaches: a computational and a clinical approach. The clinical aspect of the project will involve recruiting patients with severe mental illness into our study and following them over a year to explore the interplay of various parameters, including their metabolite levels, sleep, activity, and mood symptoms in a real-world setting. I believe this study is incredibly valuable in terms of its ecological validity and has the potential to elucidate mechanistic links between physical and mental health. From a personal perspective, the prospect of working with people who are directly affected by the condition I am studying is incredibly motivating.

On the other hand, the computational aspect of my research is very exciting because I will work with some of the largest health datasets in the world including Our Future Health which has recruited more than a million individuals. This is a very powerful way to gain insight into risk factors for mental illness and importantly to probe into patient-specific determinants.

Overall, my research is largely exploratory and I hope to generate new hypotheses for preventing and reducing the severity of adverse mental health events in the population.

What inspired you to carry out this research?

From a big picture point of view, I was inspired to do this research as I am fascinated by complex conditions that are driven by a mixture of gene/environment interactions. Psychiatric conditions are just about as complex as it gets! These conditions are highly debilitating and my long-term vision is to contribute to the development of strategies that improve well-being in patients and in the broader population. Metabolomics is a promising field of study with regards to preventative and precision medicine. Unlike the genome, the metabolome captures the effects of both the environment and internal biological mechanisms on physiology. Thus, metabolites may represent ideal biomarkers for complex disorders. Additionally, blood-based measures of metabolites may provide insight into causal mechanisms of mental illness with evidence of metabolites crossing the blood brain barrier and driving disease-relevant processes. By stratifying patients, for example by sex, this line of research carries the possibility of accurately predicting the trajectory of mental health conditions and identifying novel therapeutic targets. The hope is that we can develop patient-specific metabolic recommendations that either prevent the onset of adverse effects or are more effective than current treatments.

Tell us about a current challenge in the field.

Mental illness is currently diagnosed based on clusters of symptoms using guidelines such as the Diagnostic and Statistical Manual of Mental Disorders. However, it is becoming increasingly apparent that these symptom-based categories of mental disorders may not represent true biological categories since:

a) they don’t map to distinct neurobiological pathways, and

b) there is considerable overlap in genetic risk factors for different psychiatric disorders.

The challenge with the lack of biological validity in the current classification system is that individuals diagnosed with the same condition may have very different underlying causes and responses to treatments. This may explain why current interventions for psychiatric disorders are ineffective for many patients as they represent non-specific targeting of symptoms instead of tailored interventions based on well-understood pathophysiological mechanisms. Projects such as The Biological Classification of Mental Disorders (BeCOME) study are seeking to address this by identifying biology-based classes of mental disorders which may enhance the translation of biomedical research into patient-specific clinical applications. The field of Metabolic Psychiatry represents a promising avenue in this regard as it may facilitate the stratification of patients based on metabolic profiles instead of the somewhat-arbitrary reporting of symptoms.

If you weren’t doing research in this area, what research would you be doing and why?

I am very intrigued by research exploring the use of psychedelics to treat mental health conditions. There is incredible anecdotal support for the efficacy of psychedelics to treat various disorders such as post-traumatic stress disorder, anxiety, depression, and obsessive compulsive disorder. However, the scientific community faces some challenges to rigorously test the efficacy of psychedelics under controlled conditions. Most notably, there is a difficulty in having a true placebo group for randomised controlled trials since participants and observers are usually unblinded due to the side-effects of the drug (altered mental states and behaviours). Nevertheless, there are attempts to try control for this by accounting for patients’ expectation that the drug will work or using active placebos that mimic some of the drug side effects. I look forward to seeing whether well-designed scientific studies can reproduce the promising individual accounts of the healing powers of psychedelics.

In Conversation with Christina Steyn

Please share a little about yourself.

Tell us a bit more about your current work.

What inspired you to carry out this research?

Tell us about a current challenge in the field.

If you weren’t doing research in this area, what research would you be doing and why?

Baszucki Trials Meeting 2024: The Impact of Lived Experience in Metabolic Psychiatry Research