Scientists Find What Lack Of Motivation Looks Like In The Brain
Did you know that your brain circuits can actually change when you're feeling unmotivated?
Although it might take some time for this change to occur (thankfully, we're not talking a couple of slow Monday mornings), research has found what chronic lack of motivation could look like on a brain scan. This new study, published in the journal Neuron, has discovered how the brain changes in mice who experience lack of motivation, a common symptom of depression.
Past research on depression has used similar animal studies to categorize mice as either stressed (meaning depressed) or non-stressed (not depressed).
However, authors of the study Ignas Cerniauskas and Stephan Lammel, Ph.D., believed that this past research disregards the variability of the disease, as two people diagnosed with depression can experience completely different symptoms and respond to entirely different treatments.
That being said, they sought to find changes in the brain that were associated with each specific symptom rather than depression as a whole.
Mouse models have been used in depression research for the past 60 years, and scientists have been able to find that putting mice under constant stress produces at least three common symptoms of human depression: anxiety, lack of motivation, and loss of pleasure.
What's new about this study, in particular, is that researchers were able to discover the specific genes within a brain region that are associated with lack of motivation.
During the experiment, genes within a brain region called the lateral habenula were strongly turned on in mice that showcased reduced motivation as a result of chronic stress. Anxiety and loss of pleasure weren't associated with this brain region, suggesting that different symptoms of depression affect different areas of the brain—and as a result, require unique modes of treatment.
"Our strategy, one we think all basic researchers should adopt, is to move away from considering depression as a single or homogeneous disease," Lammel says. "Many physicians already view depression this way, which shows that it is critical to have collaboration between basic and clinical researchers."
Once these researchers can figure out the brain markers for anxiety and loss of pleasure, maybe we can start to devise specific treatment plans for each symptom. After all, health care professionals are quickly becoming enamored with personalized medicine, and this new wave should go beyond physical health and include psychiatric disorders like depression as well.
Here's what that precision medicine would look like in a mental health setting, according to Lammel: "If we had a biomarker for specific symptoms of depression, we simply could do a blood test or image the brain and then identify the appropriate medication for that patient. We think that our study not only has the potential to transform how basic scientists study depression in animals, but the combination of anatomical, physiological and molecular biomarkers described could lay the foundation for guiding the development of the next generation of antidepressants that are tailored to specific depression symptoms."
While the next generation of antidepressants sounds promising, this new research can only lay the foundation for this future of personalized mental health care. Lammel says we have a long way to go before his vision can become a reality: "That would be the ideal case, but we are far away from that situation right now."
Either way, it sure is a hopeful start.