i just want to say that's not exactly true- while human rights for psych patients do completely suck, i was just inpatient at mclean during a manic episode after a suicide attempt and i successfully refused everything [antidepressants and antipsychotics] but benadryl for sleep for the entire week.

Sure. But it was at their discretion. I wasn't saying they would do anything to one against one's will, just that they're always going to have that option. And that's the point: nobody will make the guarantee the OP was asking for, and for a very good reason.