Abstract
The nervous system is not just a target organ for synthetic steroids. It is also controlled in a certain manner by steroids synthesized de novo in the brain, at the level of both neurones and glial cells. The impressive recent number of literature studies, clearly demonstrates the presence of enzymes necessary for syntheses of central neurosteroids and also the mechanism by which they act. Neurosteroids play a considerable part as an endogenous modulator of brain function and behaviour processes, and the decrease of their concentration can be associated with the pathophysiology of different neurological diseases accompanied by cognitive disorders such as depression, anxiety, schizophrenia, Alzheimer disease.