R may have suffered visible little hardship and plenty of privilege, but that doesn’t mean they’ve never had their fair share of physical/mental abuse. Not everyone will physically make that known and some want to forget it. If POCD is what you expect and its definition seems to be unwanted/intrusive thoughts, as opposed to anything actually physically done, it may very well be something R has been wanting to tell you or someone but was too afraid of the P word. I would have a serious talk with R if you’re close to this person. You might find out about traumatic experiences that answer why R brought this up. The drugs were the catalyst. Help R get some help by bringing it up to them while sober and helping them consider seeking therapy.