I couldn't tell you quite when I read this.. I would guess somewhere mid-late 90s. (Possibly as late as the early '00s, but I'm pretty sure it was the 90s.) I think it had a blue cover on it, and it's entirely possible that I'm confusing that with Dreamfall by Joan D. Vinge, but I could swear that it had a figure (guy) on the left, with some floating white orbs and a couple of glass jars.
The book starts with a bunch of kids on an alien planet. The kids' parents/human community (colony?) on the planet have all started some kind of (drug?) use (smoking? maybe?) that is available locally (maybe by/from aliens on the planet?) and are becoming/have become completely apathetic to the world around them. They descent into apathy is such IIRC that they just start dying off because they no longer can care about anything/have the motivation to exist at all.
There's some kind of intercession by some organization (government?), the whole scenario gets incredibly publicized (the kids get [in]famous because of what happened to their parents/human colony/everyone on the planet?). The kids (I think there's six of them?) all get split up and are forbidden to ever contact each other or be in contact with any other alien species (?) again in their lives.
At some point later (I don't remember if there's intermediate plot or if the book just skips to them being adults), they're in different places around the (universe? galaxy?) and they start dying. But because of something that happened when they were kids on the first alien planet, their souls have to be (caught? captured? saved?) in (jars?). One of the kids-now-adults (a guy, I think), visits the location of all of the others of the group either just after or when/as(?) they are dying to (capture?) their souls, and then takes them all back to the alien planet.. for.. something? Somehow they're all reunited (as souls?) (maybe with the aliens somehow?)
I wouldn't say it was the most groundbreaking book I ever read, I remember randomly picking it up out of the Sci-Fi section at (Walden?) Books/some book store because it looked interesting. But it popped up in my memory recently, and its driving me sideways that I can't think of a title, or author, or anything else useful about it that might be able to help find it.
Any assistance would be greatly appreciated.