I am also very interested in Deep Brain Stimulation, and looked at the sites that Sara posted and some others.  In response to your question, Sara, t does seem like it could be a life-long cure, although the pacemaker would need to be continuously running to maintain the effects.

In deep brain stimulation, electrodes are inserted into the brain and are connected with wires under the skin to an electronic impulse generator implanted in the chest. The electrodes emit current that continuously stimulates specific areas of the brain.

So, while there are clear advantages to the many and often conflicting side effects of medication, DBS had the disadvantage of requiring an electrode in your brain for your whole life.  Although, compared to taking medication daily, it could be less of an interference once the patient becomes accustomed to it.  I wonder how much maintenance something like this would require (how often would it need to be checked, re-adjusted, etc.)  Also, knowing how amazingly plastic brains are, do you think the brain of a depressed person would adjust over time to the stimulation and require increasingly more stimulation to have the original effects?  I was interested to read in the article that Sara posted that stimulating the brain did not activate an area that was not active enough.  Rather, it does the reverse, and somehow the electrode stimulation calms a hyperactive area (Brodmann-25).  The article at this site (http://www.dana.org/news/cerebrum/detail.aspx?id=12622) that Sara provided (sorry for stealing your info Sara, but it’s really good and I wanted to make sure everyone saw!)  gave some great insight into why this area in particular is being stimulated.   I liked this quote because it explained in non-biologist terms the interaction of the different areas in the circuit that was focused on.

First, Mayberg mapped the depressed brain on medications, then on therapy and then on a placebo pill. Each step of the way, she carefully charted the brain as if it were a city of streets and avenues. She realized that treatments took different roads but ultimately arrived at the same address. That was why people with depression could get better many different ways, even with a placebo pill.  The limbic structures that regulate mood feed into the frontal cortex, striatum, thalamus, hypothalamus and brain stem. These regions communicate with one another all the time, and problems in the circuit could lead to difficulty with thinking, attention, mood and behavior. Mayberg found that these circuits, particularly a hyperactive network of brain cells in the subgenual cingulate region, also called Brodmann area 25, are abnormally overactive in depression.

I’m still not clear on how a placebo pill affects those “roads” that lead to the same address, but the metaphor was interesting.  If I were to extend the metaphor to other anti-depressant treatments, it seems like many medications like Prozac etc. would be s slew of taking a bus, catching a train, walking to find a taxi, which might end up having a flat tire and not getting you there after all.  I don’t know that much about ECT, but it seems a little more direct, so maybe calling a (more reliable) cab company to get you somewhere, while DBS is teleporting.  DBS would definitely win the time race, but not everyone can afford to teleport, and once you teleport once, you’re not going to want to go back to the first route!

I’ve been looking a lot for that video that Melissa mentioned that has interviews with patients while they are getting electrode signals turned on/off, but haven’t found it yet.  I’ll keep looking and post it if I find it!