Whatever. Go my "addiction runs in the Jakobs bloodline" headcanons.
Singleton: Drank a lot and smoked a lot. He started not just the Jakobs gun business but also the almost equally lucrative Jakobs liquor business (then again the "pioneer fleet" that the family lived on before their crashlanding was awash in shipside distilleries and breweries, sooooo). Also started the whole aging gunpowder thing - even though he was unquestionably an User of Substances he made sure the Substances were of the highest quality, hand-rolled cigars and all. Arguably a nymphomaniac.
Wharton: Didn't drink or smoke that much, for a Jakobs, and when he did it was exotic stuff (cranberry wine, rolled herbs etc). However, y'know how in the victorian age you could just buy cocaine pills at the pharmacy? Yeah Wharton was That sort of guy. Opium, ye olde white powder sniffed off his wife Mariam's strapon, et cetera. I consider this guy to be to blame for Endless Horizons and he definitely snorted straight refined malleus mutatio at least once. Liked to speak of his love of collecting things like lighters or marbles as an addiction even though it was just garden variety autism, not a genuine hoarding disorder.
Maddox: Smoked very little, and what he did smoke was usually non-tobacco calming herbs, and it had to be hand rolled in front of him and triple-checked in case someone laced it. He did however drink like a goddamn fish to try and numb his crippling OCD. Didn't particularly care about the quality of his drinks as much as, again, the fear of poison, so he always had someone taste test it before he drank it himself.
Montgomery: Semi-canonically the Jakobs clan's strongest alcoholic. The other Jakobses would at least try to pick the finest whiskey to sate their thirst, this mf was chugging entire crates of shitty Swampbloom Ale. At least, after his wife died. Before that he didn't drink that much, but he did smoke a lot - even though a lot of the manor had fallen into disrepair, he maintained the smoking room because he and Maggie were chuffing fat darts in there. Both of them would put out their cigars on anything in sight if there was no actual ashtray nearby (Mag has definitely put out a few of hers on his skin).
Wainwright: Canonically an alcoholic (even if a lot of people in the fandom dont realize it) at least through a large part of BL3. Drank almost solely Quality(tm) whiskey (in his later years at least, when he was younger he certainly drank worse shit at random Edenian bars), but then it all ran out - by the time the Vault Hunters meet him, he's cold sober with severe withdrawal symptoms and at least somewhat malnourished. By the time of GL&T he gets a bit better but it's only *after* GL&T that he realizes he might have a bit of a drinking problem and it's not a pretty epiphany. He genuinely gets really really sick and it all comes crashing down on him: losing his family, almost dying multiple times, et cetera... Alistair helps him like. Yknow. Live(tm) and both of them decide that losing eachother is Scary as shit and that drunk Wainwright just, is Strictly Worse than sober Wainwright and it hurts Alistair so much to see his beloved so unwell. In fact this situation is not healthy for either of them. They both support eachother and grow as people and I think Wainwright does eventually recover (there's a reason I make it a point in my recent-ish fics to describe whatever drink he and alistair are imbibing as non alcoholic, like orange juice). It certainly helps that his preexisting Whiskey Snobbery(tm) can be quite easily translated to the wonderful world of Tea Snobbery(tm) that Alistair is more than happy to introduce him to. Also, smokes, but only the finest cigars and only on rare occasions, usually alongside his hubby (he deserves nasty t4t say gex and the subsequent fine cigars and tea okay, he's been through a lot). Gaige would try to persuade him to try weed but he wouldn't be convinced