At the moment E4's Sunday-night Simpsons block, rather than running episodes in order like they do the other six nights of the week, is a theme night, with five episodes connected by something. Thus far they've had a Treehouse of Horror night, a night of Homer episodes for Father's Day, a Lisa Night, next Sunday is based around musical guest stars... it's a cute little touch, especially since each night has a name given to it which shows up in the EPG.
I was quite late to notice this, though, and only spotted yesterday what they'd run on 8th June.
Uh. Did they seriously run a theme night based around drugs? It's hard to see any other line of logic that could connect those five episodes. The Internet Archive to the rescue...
Riiiiiiiight. The theme is "weird and far out episodes". Nothing to do with drugs at all.
Sure.