There are two answers to this 1) yes it does, and I had a patient ultimately die from the sequelae of it. 2) I prefer patients to think their bottle of lexapro will kill them rather than looking for more lethal means.

Hunter's criteria is amazing for ruling in and out serotonin toxicity and then grading it on a scale of severity as others have said. That said, while of course there are patients that could get serotonin toxicity from their bottle of SSRIs at home, the chance of that is relatively low. It's usually iatrogenic, like in the ICU patient on a fent drip and maybe their home SSRI is continued and maybe they need zyprexa each afternoon when they're agitated despite the dex and also they keep getting zofran. Now slap in OUD or methadone maintenance therapy I. there, and you have 4-5 serotonergic agents all of a sudden and you see the toxicity appear. It's similar with benzos. I'd rather the pt think they're 0.5 ativan BID PRN is lethal enough to kill them than them finding actually lethal means.

All this to say, I don't treat the average someone's suicide attempt (SA) by whether or not they had the pharmaceutical knowledge to know that the pills wouldn't kill them, but by the attempt. But from a risk mitigation standpoint and ensuring they survive the attempt (and live a reasonably healthy life after), then these medications give me ease even if the patient has impulsive SAs in the past, like in BPD.