Creswell joined the University of Reading as a research fellow in 2003, where she eventually was promoted to a National Institute for Health Research research professorship. At the University of Reading she led the Anxiety and Depression in Children and Young People clinic. Creswell studies why some children develop anxiety disorders. She identified that anxiety disorders often emerge before the age of 12 and develop in preadolescence. In a meta-analysis of prevalence data, she showed that 6.5% of children suffer from anxiety disorders, but only 2% of those who meet the diagnostic criteria for anxiety disorder seek any effective treatment. In fact, only around 40% of families of children with children seek any type of help. She has studied how the relationships between children and their parents impacted their anxiety. As part of this work, Creswell showed that children of anxious parents are more likely to become anxious, but that anxiety is also influenced by social, environmental and biological factors. She showed that anxious children were more aware of signals from their parents; and that non-anxious children were less likely to be aware what their parents were doing. As a result of this work, she developed a therapist-guided, parent-led cognitive behavioral therapy for the management of child anxiety disorders, which is a now available on the National Health Service. She demonstrated that only 5 hours of therapist-supported training was enough to support parents in helping their children tackle anxiety. Unfortunately, this type of cognitive behavioural therapy doesn't work for everyone, and in particular does not work when the parents who have anxiety themselves. She has shown that this type of CBT does not work in all patients, and has since investigated novel treatment strategies for this group. She joined the University of Oxford in 2019. At Oxford, Creswell leads the Emerging Minds Mental Health Network. Emerging Minds is a network that looks to reduce the number of children who experience mental health challenges. After joining the University of Oxford, Creswell worked with Daniel Freeman to develop virtual reality environments that encourage children to test their fears. Creswell is a member of the scientific advisory group of Evidence to Impact, an not-for-profit organisation that looks to improve public health. During the COVID-19 pandemic, Creswell co-led the Co-SPACE. Co-SPACE looks to understand how families cope with coronavirus disease and looks to understand the impact of the pandemic on metal health. In May 2020, Creswell released the first round of results from the Co-SPACE study, showing that work and their children's wellbeing was the most frequent source of stress for parents. Her study revealed that only 1 in 5 families who had previously received care continued to do so throughout the lockdown. In particular, Creswell noted the highest levels of stress amongst parents of children with special educational needs.
