Cognitive and behavioural disorders are among the most frequent emergencies faced by geriatricians at patients' home. They include some clusters of symptoms such as agitation, verbal and physical aggression, apathy, depression and psychoses with positive and negative symptoms. Several neurotransmitters are involved in the onset of disruptive behavior in demented patients: acetylcholine and monoamines (noradrenaline, serotonin and dopamine). First of all, the appropriate management of demented patients with behavioural disorders requires an approach that is continuous, multidimensional and multidisciplinary. Geriatricians, general practitioners but also neurologists, psychiatrists and other specialists can be involved. Furthermore, the approach has to be based on a network of integrated social and health services.