The present invention relates to a composition including a mix of a polysaccharides having: 15% to 50% of glucoside linkages 1-6 a reducing sugar content of less than 20% a polymolecularity index of less than 5 an average molecular weight with number Mn of less than 4500 g/mole and at least one active agent for treating stress, anxiety and depressive behaviour, sleep disorders, obsessive-compulsive disorder, bulimia and epilepsy in humans or animals. The present invention also relates to the use of the polysaccharide for treating stress, anxiety or depressive behaviour, sleep disorders, obsessive-compulsive disorder, bulimia and epilepsy in humans or animals.