stevedonovan t1_j83apdg wrote

Even then, the actual genetic differences (and hence protein expression) can be scattered all over the genome - only a few conditions are definitely linked to a single bad gene. There are studies which show that there are about ten genes directly implicated, and that it is mostly an inherited condition. Not an easy target for drug discovery, so mostly we put a lid on the symptoms with antipsychotic drugs, which are not fun and have neurological side effects.

Also, you can have the bad genes and not end up inflicted, just be 'functionally eccentric' or even very creative. (Not so uncommon for talented families to have the curse of madness). So, there's environment and epigenetics and all that.

Tlr;dr: the mechanisms are complex, treatment has been palliative.