The publication itself, which seems to be legit, and well done.
Haven't had a chance to read all of it, but it isn't badly executed by a quick scan.
Edit: I've had a chance to read it in full.
About half of it is over my head. Just don't have the biochemical background to be able to interpret much of the metabolites they were measuring.
That being said, that stuff isn't actually important for casual interest.
Here's the key points I found:
First, the study was mice only. While mice are excellent for this kind of work, you can't guarantee things will be a 1:1 result in Holland p.
Second, the study was for low dose levels, and only delta-9 thc, with no other cannabinoids being used at all.
Third, the study was relatively short, with 42 days being the longer end.
Fourth, and this is the cool part, changes in the relevant metabolites and brain samples had benefit at the 14 day mark. So, if this does translate to human effects, short term, low dose use of delta-9 may be a valuable option. That's years away before this could be confirmed as valid for humans, but the effects were significant.
All of that means that just smoking weed, you aren't going to duplicate the conditions of the study. If you're taking in enough to get high, you're at a higher dose than the study, and that may cause an opposite effect long term.
This is a very focused experiment, with well defined limits and goals. The information gained can not be used as an indicator that smoking herb as an adult human will give any benefit, much less what is in the title of the article.
Think of this study as step one in maybe ten steps you get to the point where it would be useful for indicating benefits in humans, assuming everything went right along the way.