Patent ID: 8552000

Claim:
A method for treatment of senile dementia, which comprises administering an effective amount of an imide derivative of the formula [1]: wherein Z is a group of the formula [2]: in which B is a carbonyl or a sulfonyl; R 1 , R 2 , R 3 and R 4 are independently a hydrogen atom or a lower alkyl, provided that R 1 and R 2 , or R 1 and R 3 may combine each other to form a hydrocarbon ring, or R 1 and R 3 may combine each other to form an aromatic hydrocarbon ring; said hydrocarbon ring may optionally be cross-linked with a lower alkylene or an oxygen atom; said lower alkylene and hydrocarbon ring may optionally be substituted by at least one alkyl; and n is 0 or 1, D is a group of the formula [3]: —(CH 2 ) p -A-(CH 2 ) q — [3] in which A is a hydrocarbon ring optionally be cross-linked with a lower alkylene or an oxygen atom; said lower alkylene or said hydrocarbon ring may optionally be substituted by at least one alkyl; and p and q are independently 0, 1 or 2, G is N, CH or COH, and —Ar is an aromatic heterocyclic group, an aromatic hydrocarbon group, benzoyl, phenoxy, or phenylthio, or G is a carbon atom, and —Ar is biphenylmethylidene, where said aromatic heterocyclic group aromatic hydrocarbon group, benzoyl, phenoxy, phenylthio, and biphenylmethylidene may optionally be substituted by at least one group selected from a lower alkyl, a lower alkoxy and a halogen atom, or an acid addition salt thereof.