> it means that no, behavior change could not do the the trick.

Or it could mean that the therapist didn't do a great job / didn't account for the individuality of the person

You assume they only tried with one therapist. Most people I know with treatment-resistant mental illnesses, including myself, try many over years if not decades. This person probably had to go through a whole series before even being allowed to move on to something like the study here.

Bingo. Rather than assuming that someone just didn't have a good doctor and then gave up trying, I would actually guess that most people with treatment-resistant depression who are actively seeking treatments (such as ketamine or rTMS) have gone through many, many doctors and many, many treatments.

For many people with major depression, this isn't something you can just think your way out of or face your way out of. There are biochemical factors at play. Just like someone with diabetes can't exercise their way into a working pancreas, someone with major chronic, major depression can't just behavioral therapy their way into treatment.

Can behavioral therapy help? Absolutely. Is it going to be enough for people with hard to treat cases? Absolutely not.

    it means that no, behavior change
    could not do the the trick

I am not sure. It could also mean that the no change in behavior has been achieved.