About the Authors

Irene J. Higginson

irene.higginson@kcl.ac.uk (IJH); wei.gao@kcl.ac.uk (WG)

Affiliation Cicely Saunders Institute, King's College London, London, United Kingdom

Wei Gao

irene.higginson@kcl.ac.uk (IJH); wei.gao@kcl.ac.uk (WG)

Affiliation Cicely Saunders Institute, King's College London, London, United Kingdom

Tariq Zaffer Saleem

Affiliation Cicely Saunders Institute, King's College London, London, United Kingdom

K. Ray Chaudhuri

Affiliations Institute of Psychiatry, King's College London, London, United Kingdom, National Parkinson Foundation International Centre of Excellence, Kings College Hospital, London, United Kingdom

Rachel Burman

Affiliation Cicely Saunders Institute, King's College London, London, United Kingdom

Paul McCrone

Affiliation Institute of Psychiatry, King's College London, London, United Kingdom

Peter Nigel Leigh

Affiliation Institute of Psychiatry, King's College London, London, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: PNL IJH TZS KRC RB PM. Analyzed the data: WG IJH. Contributed reagents/materials/analysis tools: WG IJH PNL. Recruited and interviewed patients, trained other interviewers, entered, checked and cleaned data: TZS. Senior investigators and led the study: PNL IJH. Designed and executed the analysis plan: WG IJH. Drafted manuscript: IJH PNL WG. Made critical revisions: TZS KRC RB PM.