A 1,4-substituted cyclic amine derivative represented by the following formula or a pharmacologically acceptable salt thereof:
1
wherein A, B, C, D, T, Y, and Z each represent a methine or a nitrogen linkage; R
1
, R
2
, R
3
, R
4
, and R
5
each represent a substituent; n represents 0 or an integer of 1 to 3; m represents 0 or an integer of 1 to 6; and p represents an integer of 1 to 3. The compounds have serotonin antagonism. They are therefore clinically useful as medicaments, in particular, for treating, ameliorating, and preventing spastic paralysis. They are also useful as central muscle relaxants for ameliorating myotonia.