Ketamine infusions are increasingly proving their ability to improve treatment resistant depression, suicidality, PTSD, and more. And as research continues into this powerful drug, science is beginning to explain how ketamine infusions treat depression.
A single, definitive answer doesn’t exist to this question. Our brains are complex as are the causes behind depression. But the common finding is that ketamine infusions change the anatomy of the brain. And, as Carlos Zarate from the Mood and Anxiety Disorders Program at the National Institute of Mental Health told NPR in 2012, it’s possible to see that change simply by studying rodent brain cells under a microscope.
Healthy neurons look like a tree in spring, while depression causes those neurons to shrivel. “What happens in depression is there’s a shriveling of these branches and these leaves and It looks like a tree in winter. And a drug like ketamine does make the tree look like one back in spring,” Zarate told NPR.
Below, you will find descriptions of research detailing how ketamine affects the anatomy of the brain.
Ketamine and NMDA Receptors in Rodents
A 2017 study conducted by the Columbia University Medical Center verified that ketamine infusions can reduce major depression symptoms in hours – compared to the weeks required for prior antidepressants to work. And other research has linked ketamine infusions to blocking N-methyl-D-asparate (NMDA) receptors in the brain.
A 2018 study conducted by researchers at Zhejiang University in China further expanded on this research by tracking changes in the lateral habenula – a very small region of the brain located deep in its center.
The researchers found that rapid bursts of neuronal activity in the lateral habenula in rodents was directly linked to depressed behavior in the animals. The researchers then confirmed that the neuronal activity was dependent on NMDA receptors – which ketamine blocks. The researchers treated the rats with ketamine which quickly reversed the depression symptoms.
Ketamine Rebuilds Brain Anatomy Destructed by Stress
In 2019, the journal Nature published findings from a research team led by Dr. Conor Liston of Weill Cornell Medicine on the effect of stress on the prefrontal cortex of the brain.
Using high resolution imaging of neurons in the prefrontal cortex, Dr. Liston’s team found that mice exposed to long-term stress and exhibiting signs of depression experienced loss of dendritic spines in their prefrontal cortex. Dendritic spines are a part of neurons, and they affect synaptic strength and electrical signal transmission to the neuron’s cell body.
When the mice were treated with ketamine, two things happened. One, ketamine restored the disrupted circuit activity in the mice’s prefrontal cortexes which quickly relieved the abnormal behavior they were exhibiting due to their stress exposure. Two, the ketamine treatment caused new dendritic spines to develop, rather than simply halting the spine loss.
“What happens in depression is there’s a shriveling of these branches and these leaves and It looks like a tree in winter. And a drug like ketamine does make the tree look like one back in spring.”
Other Ways Ketamine Affects the Brain’s Anatomy
Other research points to ketamine blocking NMDA receptors in the brain and increasing the amount of the neurotransmitter glutamate between the neurons. This then activates connections between the AMPA receptor. Blocking NMDA and activating AMPA receptors causes neurons to formulate new pathways for signaling – a process called synaptogenesis.
Ketamine Works to Quickly Treat Depression
Ketamine is growing in popularity as a treatment for treatment resistant depression. More research like the studies described above further explain why ketamine works so well for treating depression. And if the scientific evidence isn’t enough, more people are sharing their success stories – like this one from Thomas who suffered from severe depression, suicidality, and PTSD.
Ketamine infusions are not a stand alone treatment for depression. Rather, they are an option when other treatments haven’t worked. And doctors recommend that they be administered in conjunction with other therapies. But, 70% of people who’ve received ketamine infusions have found relief from their treatment resistant depression.
Are you curious whether ketamine infusions could help you? Simply schedule a free 15 minute consultation with one of the doctors at Virginia Infusion Therapies in Leesburg, Virginia.