Found messages about drugs in my 6th graders messages

TL;DR worried my 13 year old and his friend might be starting to experiment with drugs

I haven’t brought it up to him because I want to handle it correctly. I was looking through my sons (13M) messages on his Roblox account. Hes been acting different lately, sleeping a lot and generally being a recluse in his room. I hoped it was just a teenager not wanting to be around his mom and siblings because we’re so lame, but I still worry. He made a new friend at school and the change seemed to correlate with that. That friend (12 or 13F) had sent him a slew of concerning messages and one that stuck out to me was “I just inhaled my ADHD meds im so high rn”.

This is literally my biggest fear. I have spent countless hours worrying that my son will go down the same path I did. I struggled throughout his life with a mixing pot of mental illnesses, undiagnosed autism and addiction, along with an abusive relationship in his early years and my significant other ODing in 2021. His father was in jail until he was a preteen, stealing for dope. There was never a moment I didn’t love him with all my heart, but I know the shit he went through will stay with him forever, because it’s the same shit I want through. I know what path it led me down.

He deserved better, I needed to do what my parents didn’t and change his path. I got clean, spent years in therapy and 6 months in a php group that used a lot of dbt techniques. We moved out of the city to a nice suburban area so he could have a better shot at life. I’m in the process of starting him in therapy. I know there’s a big chance she’s just being an edgelord, but there’s also the chance she’s not. This is the age my friends started experimenting. Someone please tell me how to approach this??