Many (if not like more than half, I forget the statistic..) of those overdose deaths result from combining a GABAergic like alcohol or especially benzodiazepines with an opioid.

I wonder why mixing cns depressants is so common? Is it because opioids are so expensive / hard to get, and benzos/alcohol easier to get and cheaper? Or is it simply a better feeling mixing them...

There's also no literature on the subject. So if you need benzos and opiates, there's zero guidance on what's safe. Just "we don't know, we don't measure, don't do it". In other words, abstinence.

Some people take them to increase the nod. Others might have insomnia and don't want to take so much opiates to really sleep.

Edit: And there's obviously some information on this, somewhere because e.g. IV opiate+midazolam is quite a common thing. [In a 3rd world pharmacy, I was actually offered liquid midazolam as a sleep aid when I complained long-lasting benzos were too long-lasting and asked for a medium-duration sleep aid.]

Both, and 3. throwing caution/life to the wind..

oh, and 4. combining a stimulant with a larger/more euphoric dose of the CNS depressants so if the respiratory stimulating effects of the stimulant run out first, respiratory depression ensues

In my experience doing a heroic amount of opioids was enough to not care, uppers mixed in as anti-nod.

I didn't understand why people mixed in benzos, unless to curb withdrawals.

and SSRI's, if someone takes herion, zoloft, and xanax and OD's from zoloft, it gets placed in the prescription and illegal category. Instead of quantifying the actual numbers and being precise. So even though zoloft killed them, it will go under opioids.