Behavioral and psychological symptoms of dementia (BPSD) occur in 50-90% of patients with Alzheimer's disease (AD). They cause premature institutionalization, increased costs of care and significant loss of quality-of-life for the patient and his/her family and caregivers. Non-pharmacological interventions are first-line in dealing with milder BPSD, while for moderate to severe BPSD, medication is clearly indicated in conjunction with non-pharmacological interventions. An imbalance of different neurotransmitters (acetylcholine, dopamine, noradrenaline, serotonin) has been proposed as the neurochemical correlate of BPSD. An involvement of some specific brain regions responsible for emotional activities (parahippocampal gyrus, dorsal raphe, locus coeruleus) and cortical hypometabolism have been suggested to contribute to BPSD. Atypical or novel antipsychotic drugs represent the reference drugs for treating BPSD. Among these, risperidone is considered as a drug of choice. Also, selective serotonin reuptake inhibitors (SSRIs) are useful in the treatment of BPSD.