I take Lexapro, Lithium and Risperidone daily. The Lexapro was the last to come, and it is an antidepressant. It took me out of suicidal thought for a week, but after that my mood was up, I was more motivated, but suicidal again. So now I am a motivated suicidal due to Lexapro, and it gave me the energy to travel 400km two times in a week just to buy Amitriptyline to kill myself (I live in south Brazil, near Uruguay, and in Uruguay they sell almost any meds without prescriptions to anyone).
I thought I would be able to get the benzos prescription yesterday (don't know why I didnt buy it in uruguay), but instead the dr just gave me another antipsychotics. That sucks, and maybe I will need another trip to Uruguay to finish the job.
Answering to your question: I would never try to ctb on the pills I usually take, basically because I have no information about their lethal dose. I think that's why there are so many failed attempts: people take a handful of any shit without knowing if it has a chance to work. Sometimes you die, most times you don't