As someone who has OD'd on both antipsychotics and antidepressants, simply, don't do it. Prescribed medications have a very large safety margin and you'd likely just suffer. Idk if it happens with everyone, but for me antipsychotics at higher doses causes akathisia which is uncontrollable need to move your muscles but being an OD, you'd also be passing out. For me, I was drifting into unconsciousness but kept waking up because my muscles needed to move in the weirdest ways and nothing satisfied that urge. You also run the risk of Serotonin Syndrome with antidepressant overdose and that is not fun.