An increased research interest in the relation between diabetes mellitus and dementia or deterioration of cognitive functions has been recently noticed. The relatively rich scientific literature in this topic shows that diabetes mellitus itself can cause an impairment of cognitive functions regardless patient’s age or the fact whether he has type 1 or type 2 diabetes mellitus. Type 1 diabetes mellitus leads to a psychomotor retardation while type 2 diabetes mellitus tends to be associated with impaired storage of new information. The exact mechanism through which diabetes impairs cognition has not been explained sufficiently yet, but several hypothetical mechanisms which might explain the relation between diabetes and impaired cognition have been proposed. To explain the etiopathogenetic mechanisms underlying the relation between diabetes and dementia, further research, especially research focused on process clinical-imaging studies or clinical-pathological studies is necessary. As far as clinical practice is concerned, it is important to bear in mind that prevention, timely diagnosis and optimum treatment of diabetes may help to reduce incidence of dementia or cognitive functions’ impairment.

        Key words: diabetes mellitus, dementia, cognition, impairment.