While we found some limited evidence of association between high HSV‐1 titres/IgM and rate of decline on MMSE as a surrogate marker of global cognitive function, the small effect size and lack of association with rate of whole brain atrophy, is consistent with studies suggesting that any association between HSV‐1 infection and cognitive decline, if present, is likely to be subtle.9 This evidence concerns the gene CD40LG and Mental deterioration.