Music as Medicine!
There have been numerous studies about the effects of music and sound on the human body, all of which seem to conclude in one way or another that sound (or at least the frequencies and waves it gives off) does indeed have some influence over our physicality. If this is the case, then imagine how much more "in-tune" we would be if we we're able to recognize which sounds (or for that matter what kinds of music) have an ill effect on us, as we could then re-tune to a pitch that resonates with our physical self.
With the recent advancements in music and sound therapies working in accord with alternative medicine, we are at a place where the answer to a migraine for some may be a prescription from your doctor and could be something like "play two sonatas and call me in the morning." But even long before the idea of music as medicine became a reality, music has been healing on it's own for years and has long been a positive creative outlet. I grew up a hyperactive kid who needed meds to keep me at a manageable level, yet once I began to play guitar at age 12 it was clear to me that my problem was bottled up energy and food allergies, not any real chemical imbalance. So I soon realized that playing guitar (especially learning those Yngwie licks & Metallica tunes) was a great way for me to release that bottled up energy I mentioned, which in the end made a much more harmonious me!
Music can be a lot of things to a lot of people and each of us has our own goal and purpose for picking up the guitar and finding the discipline within ourselves to learn to play it. But I like to think that for all of us who play guitar, we DO get some healing benefits from doing so. At the end of the day there's nothing quite like plugging in your guitar and unplugging from the world for a bit. To just be free to express our feelings through sound gives us the unique ability to "self-medicate" most any emotional issue just by retuning ourselves to a pleasant state of mind, even if only for a while. So next time your feeling a little "off" flip the switch and ROCK ON! You might just find that your affliction has been remedied.