He smoked pot like it was coffee. Every day before bed he said if I remember right. So that leads me to believe he took lightly on rec drugs aswell.
Not to mention being on tren and all that other stuff that is known to affect your psyche.
His friends has said he had "problems" even before bodybuilding. A couple of years ago I read somewhere that Luke said he couldn't use tren due to psych issues. Whether completely true or not it means he was someone who was "sensitive" mentally. When he died it was also mentioned, I think he even talked about it on some podcast (?), that he had just started taking antidepressants.
It is known that when initiating antidepressant use suicide risk actually goes up. It's like inhibitions from the depression
lift and you suddenly get the strength to act upon suicidal ideations, you may act impulsively. Now I have no idea what is what here or Luke's mindset - just my thoughts.
It's not necessarily so that drug users think lightly of drug use, or that they don't understand the risks, it may be that
drug use seems like one of the only viable ways to survive mental torment. It can actually be a completely rational way to regulate mood. Not necessarily good, especially long term, but rational.