Well firstly issues like this need to be dealt with by medical doctors. Is he on pain medications? If one doesn't work there're a variety he can try.
For his spine I would suggest watching this video:
http://www.youtube.com/watch?v=KNmjcVazF5g (there's two parts, make sure to watch both). This is a Qigong technique for healing the spine and you can combine this with Reiki easily.
For crystals, I mentioned in a post below how to charge/cleanse with Reiki. For the spine I would suggest placing Hematite at the top and base, and along the spine. You can use a Quartz point as a "Reiki laser" and channel Reiki in a concentrated way directly to the issue.
For depression, I would suggest he carry with him Reiki-charged and -programmed (with constant healing intent using the Distance symbol) Rose Quartz (for constant love) and Black Tourmaline (for pain relief and positive thought).
