- Correspondence to Dr Christopher P L H Chen, Departments of Pharmacology and Psychological Medicine, Memory Aging & Cognition Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore;
- Received 10 October 2017
- Accepted 11 October 2017
- Published in print 30 December 2017.
- Published online 29 December 2017.
- Published first 28 November 2017.