The present invention relates to new uses of a pure 5-HT6 receptor antagonist, specifically 1-[(2-Bromophenyl)sulfonyl]-5-methoxy-3-[(4-methyl-1-piperazinyl)methyl]-1H-indole or a pharmaceutically acceptable salts thereof, for the treatment of dementia due to menopause, senile dementia, vascular dementia, chemotherapy-induced cognitive impairment and behavioral changes in dementia such as agitation, aggression, depression, anxiety, psychosis, disinhibition, or sleep disturbances. The present invention further provides use of the said compounds in the manufacture of medicament intended for the treatment of the disorders described herein.
