I doubt if any psychotropic meds could change how he is very much. He never cut the cord with Mom. He likely never will. Using other people's meds is just another manifestation of his dependency pattern. He doesn't want to really commit to having a personal program of recovery and reform for himself. He'll dabble in this or that, but always rely on Mom as the centerpiece of his "program." He may take a fit to get a concession from her, but those concessions are small things. She maintains control over the big stuff.