What happens if you overdose on antidepressants?

I don't plan on trying this!!! I take antidepressants (quetiapine 50mg, extended-release tablets). And I'm wondering what would happen if I took too many? For example, 100mg or 150mg? Would that make a difference? Especially since these are slow-release tablets and are slowly broken down by the body. Would I still experience a different effect…