In the context of the press release it was a little confusing to me because the published paper doesn't really report on anything that would be considered long-term. I assume she meant something like "the less treatment resistant, the more pronounced the effect"?

Treatment resistance probably refers to prior treatments, which is a sort of indicator of severity or, well, resistance to treatment. So it makes sense to me that people who were less resistant to prior treatments would show more immediate longer-lasting effects.

But it's confusing.

This is impressive but it's not a randomized controlled trial at all, and it's a fairly select group of patients, so it's hard to know what to make of it. TMS treatment of depression has kind of been plagued with publication bias effects -- not to say there's no effect but more rigorous meta-analyses have suggested that publication bias is significant in the area.

Sometimes with very severe patients you see more regression to the mean, in that they have bigger apparent improvements in control conditions just because they can only stay the same or get better.

I think she means "the less treatment-resistant the participants are, the longer the treatment remains effective" (not that the session drags on longer).

The results of this study are pretty exciting, but the idea of using various forms of TMS to treat depression has been kicking around for a while, and several groups have been trying to optimize the stimulation in different ways.

Here's a decent review of its effectiveness https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6582998/

and here's another group that's trying something similar: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5344760/

I interpreted this as “The less treatment-resistant participants are, the longer the [effects of the] treatment lasts,” which would make more sense.

I'm not sure exactly why, but common sense would state that, with treatment-resistant participants, you already know "1000 things that don't work", and so you've narrowed the search space.

If the way they're doing this treatment involves hitting the subject with magnetic stimulation in "all possible parts of the search space" that might potentially solve the problem, then if you've already half-treated a subject (stimulated one entire side of their brain, say) and it didn't work, that means both that they're "treatment-resistant" and that the second treatment should only focus on the other half of the brain.