Life
If there's one thing you learn from spending any time learning about the latest depression science, it's that things are constantly on the move, and new treatments are always being tested, funded, suggested, or thrown about as possible lifesavers. The amount of these cures that will actually make it to drug production and on to wide use in the population is often slim; but three recent developments in the treatment of depression stand out for just how groundbreaking, and how potentially widely available, they may prove to be. One involves no more than a trip to the local supermarket. (Another, to be fair, involves significant amounts of brain surgery, so don't think it's all low-fi.)
Depression is a persistent and worldwide issue, and many current treatments work well but for limited people or create significant side effects. There's a lot of room for improvement, and many talented scientific minds are on the case. One takeaway from the sheer variety of proposed methods and ideas, though, is that depression is a complex disorder, with many different aspects, from the brain to the gut. That complexity makes it hard to tackle, but it also provides lots of different areas for scientists to attempt to find a weak spot. And, along the way, they can try some decidedly crazy things.
Here's what's happening in depression science now.
Deep Brain Stimulation
If you're squeamish about surgery, it's a good idea to skip this section entirely. A huge issue for depression scientists — and for patients — is the phenomenon of entirely treatment-resistant depression, in which sufferers show no response to any of the myriad current therapies on the market (antidepressants of several classes, therapy, even electroconvulsive therapy, which is only prescribed in extremely severe cases). Treating depression that severe would be a massive boon and also highly marketable, and a new long-term study out of the University of Freiburg gives the first indications of a particular surgical intervention that may be helpful: deep brain stimulation.
Deep brain stimulation, as the neurological surgery department at the University of Pittsburgh explains, "involves placing a thin metal electrode (about the diameter of a piece of spaghetti) into one of several possible brain targets and attaching it to a computerized pulse generator, which is implanted under the skin in the chest below the collarbone. All parts of the stimulator system are internal; there are no wires coming out through the skin." It's a serious intervention, currently used for epilepsy, Parkinson's disease, and Tourette's, and utilizes electrical impulses that attempt to stimulate different areas of the brain.
For such an intervention to be deemed acceptable, the depressive symptoms of a patient have to be pretty severe. Only eight people were part of the Freiburg study, which targeted the superolateral branch of the medial forebrain bundle, an area crucial for the brain's interpretation of pleasure and quality of life. However, they underwent it extensively, over four years, and had their symptoms measured every month during that time. Four had their symptoms dip below the threshold for clinical depression, and seven out of the eight saw significant responsiveness. We already knew that this type of treatment on that specific brain segment worked in the first week of a trial, and in 2015 another study concluded that there was an "urgent need" to explore the process further. This is the first step, and now the University of Freiburg is mounting a bigger study, with 50 patients over five years. If that works, one day treatment-resistant depression may not be so resistant.
Lactobacillus
This is an annoying discovery for me, as I hate yogurt, but I may just have to suck it up and get some (or just a probiotic), because science is increasingly backing a theory that a probiotic bacteria has a positive influence on mood. While we've known about the link between the bacteria, called Lactobacillus, and mood for a while — scientists in 2011 found that feeding it to mice changed the way they regulated their emotions — the new study from the University of Virginia explains why for the first time, and also provides hope that it may be a mechanism that works in both mice and humans.
The gut-brain connection isn't just something dreamt up by your hippie Aunt Dot. It turns out that the gut microbiome, the microorganisms that make up your digestive system, can have some pretty intriguing influences on mental processes and mood, a news flash so big that the New York Times did a feature on it in 2016. ("Can The Bacteria In Your Gut Explain Your Mood," it asked. The short answer is yes.) When it comes to depression, the specific mechanism of Lactobacillus appears to be to set off a chain reaction. The Virginia scientists were studying mice, and found that Lactobacillus bacteria were very vulnerable to stress and would vanish from the gut if the mouse experienced it, raising depression symptoms. Lactobacillus, it turns out, moderates the body's levels of kynurenine, which sounds like a bad Japanese anime villain, but is actually a metabolite closely linked to a bunch of illnesses and problems, from immune disorders to schizophrenia. The less Lactobacillus, the more kynurenine, and that's bad news for depression sufferers; it turns out that kynurenine diverts amino acids that could be used to produce serotonin away to do other things. It's like a problematic traffic cop, and it's getting its orders from a gut bacteria. Yes, the body is an exceptionally weird place.
The good thing about the study is that the scientists found that just one dose of Lactobacillus was enough to restore its levels in the gut and cause depressive symptoms to lower and disappear. And they're confident that will happen in people as well. So go get yourself some probiotics.