Man, are your kids great at expressing themselves. As this unfolds they develop a separate relationship with their mother as they do with you. As a father you can support them while keeping respectful boundaries in place but you can't control what they say.
In the olden days, manic/depressives (as the severe cases were called back then) were sent to farms to work. The physical exertion gave an outlet for the racing brain and brought stability. Your son's hike is probably a very good thing.
Just because you think you have an agreement with your wife in how to address concerns doesn't mean she'll follow it. And her pleas for you to 'fix' the relationship between her and your son puts you squarely in an emotional triangle which will bite you in the ass on all sides. Be consistent with your boundaries.. you are there for the kids, will not speak poorly of her, let her fight her own battles. The family meetings are a great idea.. conversation with accountability.
