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 Katie Swaden Lewis

Katie Swaden Lewis

Research Associate, Division of Psychological Medicine & Clinical Neurosciences

+44 (0)29 2068 8381
2.28, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ
Available for postgraduate supervision



I am currently a Sir Henry Wellcome Postdoctoral Research Fellow. My research investigates the link between sleep and mental health, and aims to answer questions like: "Why do sleep problems affect mood in some people more than others?" and "Can we use information on sleep to predict if or when someone will become unwell?" I use longitudinal and genetic data on sleep and mood to answer these questions, including data from smartphone apps and activity monitors.


Committees and reviewing


  • Journal of Adolescence
  • Frontiers in Psychiatry (Review Editor)
  • Biological Psychiatry
  • British Journal of Psychiatry
  • Journal of Affective Disorders


Lewis, C., Lewis, K.J.S., Roberts, A., Edwards, B., Evison, C., John, A., Meudell, A., Parry, P., Pearce, H., Richards, N., Jones, I., Bisson, J.I. (2022). Trauma exposure and co-occurring ICD-11 post-traumatic stress disorder and complex post-traumatic stress disorder in adults with lived experience of psychiatric disorder. Acta Psychiatrica Scandanivica, DOI: 10.1111/acps.13467. Epub ahead of print.

Martin, J., Wray, M., Agha, S.S., Lewis, K.J.S., Anney, R., O’Donovan, M., Thapar, A., Langley, K. (2022) Investigating direct and indirect genetic effects in attention deficit hyperactivity disorder (ADHD) using parent-offspring trios. Biological Psychiatry, DOI: 10.1016/j.biopsych.2022.06.008. Epub ahead of print.

Lewis C., Lewis K., Roberts A., Evison C., Edwards B., John A., Lloyd K., Pearce H., Poole R., Richards N., Robinson C., Jones I., Bisson J.I. (2022). COVID-19-related posttraumatic stress disorder in adults with lived experience of psychiatric disorder. Depress Anxiety.  doi: 10.1002/da.23262. Epub ahead of print.

Oakes D.J., Pearce H.A., Roberts C., Gehrman P.G., Lewis C., Jones I.*, Lewis K.J.S*. (2022). Associations between comorbid anxiety and sleep disturbance in people with bipolar disorder: Findings from actigraphy and subjective sleep measures. Journal of Affective Disorders, Apr 12:S0165-0327(22)00404-9. doi: 10.1016/j.jad.2022.04.065. Epub ahead of print.

Lewis, K.J.S., Gordon-Smith, K., Saunders, K.E.A., Dolman, C., South, M., Geddes, J., Craddock, N., Di Florio, A. Jones, I., Jones, L. (2022) Mental health prior to and during the COVID-19 pandemic in individuals with bipolar disorder: Insights from prospective longitudinal data. Bipolar Disorders, 00:1–9. doi:10.1111/bdi.13204.

Lewis, K.J.S., Lewis, C., Roberts, A., Richards, N., Evison, C., Pearce, H., Lloyd, K., Meudell, A., Edwards, B.M., Robinson, C.A., Poole, R., John, A., Bisson, J., Jones, I. (2022). The effect of the COVID-19 pandemic on mental health in individuals with pre-existing mental illness. BJPsych Open, 8(2), E59. doi:10.1192/bjo.2022.25

Lewis, K.J.S., Tilling, K., Gordon-Smith, K., Saunders, K.E.A., Di Florio, A. Jones, L., Jones, I., O’Donovan, M.C., Heron, J. (2022). The Dynamic Interplay Between Sleep and Mood: An Intensive Longitudinal Study of Individuals with Bipolar Disorder.  Psychological Medicine, 1-10. DOI: 10.1017/S0033291721005377

Lewis, K.J.S.*, Martin, J.*, Gregory, A.M., Anney, R., Thapar, A., Langley, K. (*joint first author). Sleep disturbances in ADHD: Investigating the contribution of polygenic risk for ADHD and sleep-related phenotypes. (2022). European Child & Adolescent Psychiatry. DOI: 10.1007/s00787-021-01931-2

Lewis, K.J.S., & Gregory, A.M. Heritability of Sleep and its Disorders in Childhood and Adolescence. (2021). Current Sleep Medicine Reports, 7, 155-166. DOI: 10.1007/s40675-021-00216-z 

Gordon-Smith, K., Lewis, K.J.S., Vallejo Auñón, F.M, Di Florio, A., Perry, A., Craddock, N., Jones, I., Jones, L. (2020). Patterns and clinical correlates of lifetime alcohol consumption in women and men with bipolar disorder: Findings from the UK Bipolar Disorder Research Network. Bipolar Disorders, 22(7),731-738. DOI: 10.1111/bdi.12905

Lewis, C., Lewis, K.J.S., Kitchiner, N., Isaac, S., Jones, I.,Bisson, J.I. Sleep disturbance in post-traumatic stress disorder (PTSD): a systematic review and meta-analysis of actigraphy studies. (2020). European Journal of Psychotraumatology, Jul 9;11(1):1767349. 

Lewis, K.J.S., Richards, A., Karlsson, R., Leonenko, G., Jones, S., Jones, H.J., Gordon-Smith, K., Forty, L., Jones, L., Escott-Price, V., et al. Comparison of Genetic Liability for Sleep Traits Among Individuals With Bipolar Disorder I or II and Control Participants. (2020). JAMA Psychiatry, 77(3):303-310. DOI: 10.1001/jamapsychiatry.2019.4079

Lewis, K.J.S., Di Florio, A., Forty, L., Gordon-Smith, K., Craddock, N., Jones, L., & Jones, I. (2018). Mania triggered by sleep loss and risk of postpartum psychosis in women with bipolar disorder. Journal of Affective Disorders, 225, 624-629.

Lewis, K.J.S., Gordon-Smith, K., Forty, L., Di Florio, A., Craddock, N., Jones, L., & Jones, I. (2017). Sleep loss as a trigger of mood episodes in bipolar disorder: individual differences based on diagnostic subtype and gender. British Journal of Psychiatry, 211(3), 169-174.

Barber, S. & Swaden Lewis, K. Antimicrobial Resistance. House of Commons Library Briefing Paper CBP 8141, 15 November 2017.

Lewis, J., Bisson, S., Swaden Lewis, K., Reyes-Galindo, L., Baldwin, A. (2017). Cardiff sciSCREEN: A model for using film screenings to engage publics in university research. Research for All, 1(1), 106-120.

Dent, C.L., Humby T., Lewis, K., Plagge, A., Fischer-Colbrie, R., Wilkins, J.F., Wilkinson, L.S., Isles, A.R. (2016). Impulsive choices in mice lacking imprinted Nesp55. Genes, Brain & Behaviour, 15(8), 693-701.

Lewis, K.J.S., Foster, R.G., & Jones, I. R. (2016). Does sleep and circadian rhythm disruption trigger postpartum psychosis? British Journal of Psychiatry. 208(5), 409-11.

Lewis, K., Elam, K., Sellers, R., Rhoades K., Bevan Jones, R., Thapar, A., Rice, F., Collishaw, S., Harold, G., & Thapar, A. (2013). The Depression Impairment Scale for Parents (DISP): a new scale for the measurement of impairment in depressed parents. Psychiatry Research, 210, 1184-90.

Lewis, K.J.S., Mars, B., Lewis, G., Rice, F., Sellers, R., Thapar, A.K., Craddock, N., Collishaw, S., & Thapar, A. (2012). Do parents know best? Parent-reported vs. child-reported depression symptoms as predictors of future child mood disorder in a high-risk sample. Journal of Affective Disorders, 141, 233–6.

Lewis, K.J.S., Borst, G., & Kosslyn, S.M. (2011). Integrating visual mental images and visual percepts: new evidence for depictive representations. Psychological Research, 75, 259-71.

Public Engagement:

I have a keen interest in public engagement and I am passionate about encouraging others into science. I have worked with a number of groups including the Public Health Wales Healthy Schools Scheme, Step Up Summer School for Widening Access to Higher Education, Wales Gene Park and Cardiff Scouts.


£30,488 – Wellcome Trust Research Enrichment - Public Engagement Award (01 January 2023 – 30 September 2025).

£300,000 – Wellcome Trust Sir Henry Wellcome Postdoctoral Fellowship "Using genetics, neurophysiology and longitudinal data to disentangle the complex relationship between sleep and mood disorders" (01 October 2021 – 30 September 2025).

£44,945 – Wellcome Trust (Institutional Strategic Support Fund Consolidator Award) "Do sleepless nights lead to manic days? Using online mood monitoring and genetics to decipher the role of sleep in bipolar disorder." (29 April 2019 – 01 May 2020).


Past projects