A new £5 million study will use cutting-edge brain science techniques to investigate why repetitive negative thoughts, also known as rumination, start and persist in people with mental health disorders.
Led by the University of Oxford and involving the University of Exeter, the project will combine advanced brain stimulation, MRI scanning, computational modelling, and a pioneering pupil-based biofeedback approach to better understand the brain mechanisms behind repetitive worrying thoughts.
Repetitive negative thoughts are a known risk factor for anxiety and depression, yet the brain systems that cause and maintain them remain poorly understood. This study will be the first to bring together such a wide range of techniques to identify the processes involved and explore ways to reduce these thoughts.
Professor Ed Watkins, research clinical psychologist at the University of Exeter said: "Repetitive negative thoughts are common to many psychological difficulties and are often hard to treat. Whilst various mental processes such as those relating to attention and learning have been associated with repetitive negative thoughts, there is a major gap in understanding whether these changes in mental processes cause repetitive negative thoughts or whether repetitive negative thoughts cause changes in these mental processes. Through the novel use of neuromodulation to directly change mental processes, this study will resolve this important question."
The project will begin in February and involve 500 participants. Researchers will work closely with people with lived experience of mental ill-health to ensure the research reflects their priorities and real-world relevance.
Professor Michael Browning, Principal Investigator and Professor of Computational Psychiatry at the University of Oxford, said: "Repetitive negative thoughts can have a debilitating effect on quality of life and are a key component of mental health conditions such as anxiety and depression. Despite their significance, little is known about the neurocognitive mechanisms that underpin these thoughts, and treatment options are limited. By improving our understanding of why they develop, we hope to become better at treating them."
Teams from Oxford, Zurich and Exeter will also investigate whether repetitive worrying thoughts can be reduced by combining brain stimulation with a simple training exercise.
The brain stimulation work will be led by Professor Jacinta O'Shea, Professor Lilian Weber and Professor Miriam Klein-Flugge, using both transcranial magnetic stimulation (TMS) and transcranial ultrasound stimulation (TUS).
Professor O'Shea explained: "Non-invasive brain stimulation allows us to test how different brain areas contribute to patterns of worry and rumination. Using targeted stimulation, we aim to interrupt these patterns and reduce symptoms. By pairing stimulation with cognitive training over time, we will explore whether this leads to more adaptive, long-lasting thinking styles."
Pupil-based biofeedback - led and pioneered by Professor Nicole Wenderoth at ETH Zürich - will train participants to control their pupil size, which can influence brain activity linked to worry. The cognitive training component will be led by Professor Edward Watkins at the University of Exeter, while computational modelling will be led by Professor Rafal Bogacz at Oxford's Nuffield Department of Clinical Neurosciences.
