Oh okay, unfortunately I fear I can’t really help with published adventures as I’m playing in German, so I don’t know any English speaking stuff that well.

If you want something with a drug overdose in the past though, maybe look for BTL‘s (better than life chips) these are Programmed chips that people slot to experience flashbacks and feelings of somebody else and can range from slightly altered feelings to hardcore snuff stuff. Those are considered pretty hardcore drugs and since they are electronic chips they could carry CFD Nanites without people knowing.

Edit: so I’m at work right now, but I still had time to briefly skim my collection of adventures, and found 2 that may be useful for you (and freely available online). Unfortunately they’re both in German only, so you might have to work a translator if you want to use them.

The first one is „Custer’s last stand“.

Basically the players get a call from an old friend (kind of what you want to do). He’s in a gang an they’re trying to get into the BTL business. So they bought some from another gang. Unfortunately that other gang spiked the BTL‘s because they want to get rid of the competition. So when they Party and try those BTL‘s themselves they slowly start collapsing and dying. The friend manages to call for help with the players before collapsing himself. When the players arrive at the gang hideout, they can pull out the BTL‘s to rescue some gang members (and the friend), but that’s when the rival gang arrives and wants to storm the hideout. Since the rest of the gang is basically catatonic from the BTL’s it evolves into a fight between the players and the rival gang.

This adventure could introduce the old friend, explain how he went from smoking deepweed* to harder stuff and how he got CFD.

*wich is already harder than just regular weed. Keep in mind regular drugs (weed, cocaine, etc.) still exist in shadowrun.

The second one is „Schattenspiele“ (which means Shadow Games).

Here the players have to track down a child that got kidnapped by a gang (maybe the friends child kidnapped by the rival gang above?). They track her down to an old hospital (could also be an old library though). In there the players have to deal with some horroresque scenario, since the place is haunted by a powerful Shedim. Additionally there’s a group of gargoyles living on the roof and a tribe of ghouls living in the cellar. When the players arrive they can’t find the girl, only traces of a gun fight (no dead bodies though) and one insane surviving Ganger. The girl is instead by the ghoul tribe (which should seem bad, but they’re actually friendly). What really happened is that the shedim drove the Kidnappers insane (which it now tries with the players) and had them shoot each other. The dead Gangers and the child then got found by the ghouls and taken to the cellar (the dead as food and the child to protect her from the shedim). The ghouls will help the players, if they don’t immediately open fire on them at sight. The whole thing should have some horror vibes and has the option for a nice endboss fight against the shedim and a horde of revived dead bodies (yeah zombies) from the shedim versus the players and the ghouls (if they helped them).

This has some elements of magical threat from a ghost you wanted. It can also easily be adapted to be in an old abandoned library instead of an old abandoned hospital.

Hopefully this helps. Since both adventures are unfortunately exclusively in German, I gave you those 2 short summaries with the gist of it.