Please note that the following text should have been included at the end of this article:
TC is the author of several self-help books on chronic fatigue for which she receives royalties. ML has no conflict of interest to declare.
TC acknowledges the financial support of the Department of Health via the National Institute for Health Research (NIHR) Specialist Biomedical Research Centre for Mental Health award to the South London and Maudsley NHS Foundation Trust (SLaM) and the Institute of Psychiatry at King's College London. ML receives salary support from the National Institute for Health Research (NIHR) Doctoral Research Fellowship Scheme. The views expressed in this article are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.