It's part of the Octagon Society teachings. The idea is that depression is usually driven by repressed anger -- if you're furiously angry and you can't deal with it, you shut down your emotional energy, and depression is the result. The real challenge is that anger itself is also usually a secondary emotion -- it's easier to feel angry than it is to feel grief, fear, or shame. So to heal from depression, according to these teachings, first you have to let yourself face your anger, which is a challenging task, and then you have to do down beneath the anger to the grief, fear, or shame that lies beneath it, and that's another challenging task.

If he's interested, the Octagon Society work might be worth trying -- it's available online for free at octagonsociety.org .

In terms of positive magic, anything that directs healing energies and love toward him will help.