Summary: <p>It’s been known for years that the prevalence of MS increases the further you go from the equator, but not why. Roisin Lonergan, from St Vincent’s University Hospital, Dublin, Ireland, describes her investigations into a genetic factor and vitamin D levels, and if they can help explain this.</p><p>Also Quinton Deeley, from the Institute of Psychiatry at London’s King’s College, UK, talks about hysteria and hypnosis, and why they could stem from similar brain processes.</p><p>See also</p><p>Multiple sclerosis prevalence in Ireland: Relationship to vitamin D status and HLA genotype http://tinyurl.com/a7c5xmj</p><p>Dissociation in hysteria and hypnosis: evidence from cognitive neuroscience http://tinyurl.com/a66mpdp</p>
