NEW YORK CITY, New York - Answer: they're all just about as effective as multi-billion dollar antidepressant drugs in treating "depression".
The BBC is reporting on a meta-study by the University of Hull, where they dug around and acquired both published and unpublished trial data, instead of only the published data (which is apparently cherry-picked to put the greatest possible light on the "antidepressant" drugs). To summarize, the swanky, patent-encrusted SSRI drugs were deemed to be no better than a placebo for all but the most "severely depressed" patients.
The BBC article notes that new armies of therapists are being trained to provide "talking therapies", and a Financial Times article on the same study notes that "outdoor exercise" can be used to combat "depression."
If talking to someone "cures" them, then there was nothing medically wrong with them to begin with. If a bit of outdoor prancing "cures" someone, then they were not medically ill.
I hate to sound like a Scientologist on this, but even a crazy, blind Scientologist squirrel can stumble upon a nut.