About the Authors

Hugh S. Markus


Affiliation St. George's University of London, London, United Kingdom

Competing Interests

HM has received a unrestricted research grant from Shire but this is not directly related to the current article. Shire had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Author Contributions

ICMJE criteria for authorship read and met: HM. Wrote the first draft of the paper: HM.