Thanks—I made the mistake of going directly to the journal’s site and searching there.

Some impressions after quickly reading the paper:

• They start with the assumption that iron-age warriors took stimulants before battle (based on a comparison to other selected cultures, rather than any direct evidence) and look for any possible relevant artifacts, rather than starting with the artifacts and trying to deduce their use from the context of the finds

• They present no corroborating evidence like chemical residues or association with containers that might have held stimulants. They do mention a type of wooden box found in other graves, but no suggestion that the occurrences are correlated; they also mention metal containers found in female graves—but since the spoonlike artifacts are only found with male burials, there’s clearly a negative correlation.

• If stimulant use were as widespread as the prevalence of the artifacts suggests, you’d expect some mention by contemporary Romans or Greeks (especially given the famous description of cannabis use among the Scythians by Herodotus, and the fondness of later historians for imitating him), or some survival into medieval practice or folklore

• They mention a number of psychoactive plants based on their potential availability, not evidence of actual use—and not all of them are stimulants, or appropriate for inhalation.

• There’s no suggestion that the spoons were a standard size, as would be expected if they were intended for measuring drug doses.

In short, the paper seems a lot more speculative than the Newsweek article implies.

Are you deigning to tell me that the cisalpine Gauls are civilized?

It's hard to shoot up in a back alley when back alleys aren't a thing yet.

They used torches for that.