In schizophrenia why were going to lower down the acethylcholine after treating of such even in a normal state

in schizophrenia the dopamine is higher making acth and dopamine imbalance,so when schizo is being treated the rebound of low dopamine occurs,in this state occurs high acethylcholine and low dopamine,why we are lowering the acth although it is in a normal state instead of using both dopaminergic and anticholinergic to treat the pseudoparkinsonism?according to my knowledge we are using anticholinergic to lower down the acth-to fast reabsorb the acth from synapse down to the postsynapses.isn't it bad to alter the normal rhythm of absorption of the acth?