An imaging study involving 79 volunteers aged 44 to 88 has found lower volumes of gray matter and faster rates of decline in the frontal and medial temporal lobes of those who ranked high in neuroticism traits, compared with those who ranked high in conscientious traits. These are brain regions particularly affected by aging. The idea that this might occur derived from the well-established effects of chronic stress on the brain. This is the first study to investigate whether the rate and extent of cognitive decline with age is influenced by personality variables. Extraversion, also investigated, had no effect. The study does not, however, rule out the possibility that it is reduction in brain tissue in these areas that is affecting personality. There is increasing evidence that people tend to become more neurotic and less conscientious in early-stage Alzheimer's.
 . Exploring the relationship between personality and regional brain volume in healthy aging. Neurobiology of Aging [Internet]. Submitted ;In Press, Corrected Proof. Available from: http://www.sciencedirect.com/science/article/B6T09-4Y0TDM2-2/2/b749dc2b6b10809046fe4fb918f7960c