Deep brain stimulation - no side effects

Professor Helen Mayberg discusses the systems affected by deep brain stimulation, which seems to relieve depression without side effects.

In some ways, this system isn’t trained, and there is something about the interruption or the pacing or whatever this acute effect is that is a release phenomenon. I think it’s, in essence, a disinhibition; that the cortex has been hijacked, and you are just allowing it to go about it’s business, but that it’s something more than that, because it isn’t just that I get you back on track and you go on your way. There is something about this system that has vulnerability, and it is such an important system to evaluate everything about stress and novelty in your world; are things good for me or bad for me? You always use your emotional monitor to make decisions that it has a tendency to get stuck. So it’s using the normal process, but it doesn’t re-equilibrate and somehow we’ll need to figure out what the electricity chronically is doing that allows the system to actually go about its business, because remarkably we don’t see side effects; there doesn’t seem to be a price you pay to have this continuous stimulation going on all the time in this very vital network. It either works or it doesn’t, but it doesn’t require a higher dose over time, it doesn’t wear out, and it doesn’t give side effects, so the question is what can be wrong that this kind of intervention can just bring things back into normal tolerance limits. And equally remarkably, people’s dynamic range emotionally is fine, and one of the most interesting things is that once you have been sick and ‘dead’ such a long time, the early part of treatment is actually relearning what it’s like to have a bad day. You do have dynamic range; it doesn’t take away your ability to have a bad day, you have to relearn what that feels like because in fact the normal ebbs and flows of normal daily life has emotional ups and downs, and for these patients they are accustomed to being dead and deader with no dynamic range. And now they have to learn that having a bad day is sometimes just having a bad day, and not a relapse. So the retraining process is very critical as well, but it’s just as though this constant stimulation allows the brain to do its job and doesn’t actually charge the person with having to learn to go around something as a price of recovery.