I imagine you did not know the adult brain generates new brain cells. I think we have all thought that once the brain develops in utero, that’s it. Well, that’s not the case. And the implications for mental health are enormous.
As a psychotherapist, I talk to people about how they are feeling, what challenges exist, and what changes they would like to make. We talk about if medication helps, if there are side effects, and how to work with their medical professional. I also talk to them about how healing their brain is often part of improving their overall condition.
Until last year, I did not know how stress actually causes changes to the brain. People doing this research have known about the relationship between stress and the brain for some time, but those of us in the mental health field do not talk about it as much, or at least in these terms.
All of this new knowledge (for me) came together because of a TED Talk. Dr. Sandrine Thuret, from Kings College London, discussed neurogenesis, or the birth of new neurons in the brain. She described how they are generated in the hippocampus, an important part of the brain related to learning, memory, and emotional regulation. She talked about how neurogenesis also relates to eliminating depression, or that building new neurons and new neural connections in the hippocampus correlates with the reduction of symptoms.
Taking a step backwards, let's look at how stress causes changes to the brain, which eventually leads to conditions known as depression and anxiety.
Research supports the idea that cortisol in the brain represents much of that etiology, or how cortisol — caused by toxic stress — eventually makes its way back to the hippocampus, where there are many receptors for cortisol. The repeated assault of cortisol on the hippocampus effectively kills neurons and their connections in that region of the brain.
When this occurs, people tend to become excessively sad and fearful, or clinically depressed and anxious. Depression in this form is not just the blues — it’s a sense of vapidness, almost no feeling. Anxiety is not just nervous — it's terrified, paranoid, and socially inept. The key feature here, and what I believe relates to changes in the hippocampus, is that those feelings of depression and anxiety are almost always on, continuously holding the person hostage to suffering and isolation.
Other parts of the brain are also involved in this stress response, such as the amygdala. Specifically, cortisol from toxic stress causes the amygdala to become larger and hyper-reactive, also causing much of the fear and anxiety people experience. Importantly, research supports the idea that serotonin from SSRIs both enhances neurogenesis in the hippocampus to promote positive mood and calms the amygdala to lessen its reactivity to stress.
These discoveries around changes to the brain and neurogenesis create a new understanding, a new hope, and a new perspective. With my patients, I call this the new science of mental health, or that instead of thinking there is something wrong with them or that they have a character problem because they feel depressed or anxious, they can understand it in the sense of changes to their brain. I also tell them treatment may rely on hippocampus neurogenesis — building new neurons and rebuilding connections — as a key part of healing the brain and eradicating these disabling feelings.
Taken together, discovering the role of toxic stress in creating the experience of depression and anxiety depersonalizes the negative self-images around feeling so poorly. Understanding that toxic stress causes changes to one's brain makes that a physical reality. And understanding that neurogenesis is vital to improving one's mental health gives lasting and permanent hope that these afflictions can always be addressed.
It's time for those of us in the field of mental health to study these discoveries so that we can forge the best treatments possible in the years ahead. The new science of mental health is exciting and poses so many positive benefits to people struggling with disabling conditions, and to society as a whole.
Millions of people will feel better, which, obviously, is an outstanding goal. But also, when we feel better, we have better relationships. And when we have better relationships, we solve problems better. Just imagine what we could do then.