Footnotes

• Contributors JJM drafted the original manuscript, and it was reviewed and critiqued by AM, EK and TL.

• Funding JJM, AM and EK report no disclosures. TL receives honoraria from Abbot, Boehringer Ingelheim, Lundbeck and Orion. He has received educational grants from Bayler Schering, Biogen Idec, Lundbeck and Medtronic. He has received grants from the Irish Institute of Clinical Neuroscience, the Mater College and PRTL1 funding. TL sits on the advisory boards of Abbot, Novartis, UCB Pharma, Teva, Merck Serono and Biogen Idec.

• Competing interests None.

• Patient consent Obtained.

• Provenance and peer review Not commissioned; externally peer reviewed.