In the present study we describe a computerised but individualised approach to linguistic analysis – we propose a unifying approach, with firm grounds in Information Theory, that, independently from the specific parameter being investigated, guarantees to produce a robust model of the temporal dynamics of an author's linguistic richness over his or her lifetime. We applied this methodology to six renowned authors with an active writing life of four decades or more: Iris Murdoch, Gerard Reve, Hugo Claus, Agatha Christie, P.D. James, and Harry Mulisch. The first three were diagnosed with probable Alzheimer Disease, confirmed post-mortem for Iris Murdoch; this same condition was hypothesized for Agatha Christie. Our analysis reveals different evolutive patterns of lexical richness, in turn plausibly correlated with the authors' different conditions.