The invention relates to a method of treatment and/or prophylaxis of a disease or disorder of the central nervous system comprising administering to a mammal in need thereof an effective amount of a xanthone-rich plant extract, or a compound derived from a xanthone-rich plant extract. The invention also relates to use of a xanthone-rich plant extract, or a compound derived from a xanthone-rich plant extract, in the preparation of a medicament for the treatment and/or prophylaxis of a disease or disorder of the central nervous system and to a xanthone-rich plant extract, or a compound derived from a xanthone-rich plant extract, for use in the treatment and/or prophylaxis of a disease or disorder of the central nervous system.
