Dr. Andrew Huberman, Ph.D. is a Professor of Neurobiology and Ophthalmology at Stanford University School of Medicine. His lab focuses on neural regeneration, neuroplasticity, and brain states such as stress, focus, fear, and optimal performance.
In this episode of Huberman Lab, Dr. Huberman explains major depression at the biological and physiological level, treatments to prevent and treat depression, the chemical systems altered in depression, and a review of preventive lifestyle interventions.
Host: Andrew Huberman (@hubermanlab)
The pleasure system is the same pathway that modulates mental anguish and pain
When we pursue anything that we think will bring us pleasure, we experience a release of dopamine
Dopamine is the molecule of craving and drive
As we experience pleasure there’s a tilt on the scale of pain-pleasure and we crave more of the thing that brought us pleasure
If we remain in constant pursuit of pleasure, we’ll achieve less dopamine release every time while the amount of pain increases
To reset the balance, enter states of boredom which might even increase anxiety
Always be cautious of any state of mind or body that leads to any significant increase in dopamine release
Pain relievers can help people with emotional pain
A lot of people with depression are more sensitive to physical pain
Characterized by lows – in contrast to bipolar depression, which has a manic state followed by a crash
Depression affects us on a conscious level and subconscious (sleep, appetite, hormone)
Major depression impacts 5% of the population
Depression is the 4th largest cause of disability
There’s a significant challenge in diagnosing depression because the tool used to diagnose is language
Criteria of possible depression: grief, threshold to cry (when you didn’t previously cry), anhedonia (lack of enjoyment), guilt, confabulation, self-deprecation that doesn’t align with reality, vegetative symptoms, decreased appetite
At least three major chemical pathways in the brain relate to depression: norepinephrine, serotonin, dopamine
Norepinephrine relates to the lethargy and exhaustion
Dopamine relates to the anhedonia
Serotonin relates to the grief, guilt, and more cognitive effects of depression
The architecture of sleep is disrupted during depression
The pattern of activity in the brain during sleep is disrupted
Sleep marker of depression: early waking without being able to fall back asleep
9 pm peak in cortisol is signature of depression
Tricyclic antidepressants & MAO inhibitors increase norepinephrine in the brain
Side effects: impact libido, appetite, digestion, blood pressure
Selective serotonin reuptake inhibitor (SSRI): prevent serotonin from being wiped up by synapse; increase the efficacy of serotonin at the synapse not the amount of serotonin
Side effects: only works in about 1/3 of depression patients and can take about two weeks to kick in
20% of people with depression have low thyroid function
There are symptoms of hormonal dysfunction that can make people more susceptible to depression or make underlying depression worse
Women may experience symptoms of depression during the menstrual cycle, pre- and post-menopausal, post-partum
One of the best things you can do to stave off depression is control stress levels and particularly long term stress
There is a genetic disposition to stress – particularly a gene that regulates how much serotonin is in the brain under conditions of stress
Genetic disposition doesn’t mean you will get depression, but it will take far fewer bouts of intense stress to induce depression
The more closely related you are to someone with major depression, the more likely you are to get major depression
Exercise increases the norepinephrine in the body
Regular exercise is a protective behavior of depression and can alleviate symptoms of depression
Double-edged sword of exercise & depression: exercise can be protective and alleviate symptoms but depending on how far along you are, apathy can take over and inhibit you from moving at all
People with depression can’t access circuits of happiness, motivation, movement, etc. in the same way people without depression can
Exercise has a positive effect on the tryptophan-serotonin pathway by sequestering pro-depressive effects on the pathway, essentially limiting bad pathway
Exercise dose: 150-180 minutes exercise per week
There is an abundance of evidence pointing to excessive inflammation as a precursor or exacerbator of depression
People who are depressed have more of an appetite for carbohydrates because they are trying to get more tryptophan which is eventually converted into serotonin
Supplement to limit inflammation and relieve some symptoms of major depression: increase intake of essential fatty acids – critical threshold level: 1,000 mg EPA (not DHA, read more here)
The phosphocreatine system in the brain has been shown to be involved in the regulation of mood pathways
Creatine (monohydrate): improve mood and symptoms of major depression (dose 1g – 5g)
A caveat with creatine supplementation: shown to increase mania in people who are already manic – but this same thing could be helpful for people with major depression (not bipolar)
Keto diet has been explored for potential relief of depressive symptoms by modulating gabba – particularly in those who do not respond to pharmaceutical treatment
Ketamine and PCP act as antagonists, blocking NMDA receptor  
Dissociation induced by PCP and ketamine may lead to shifts in circuity and plasticity so depression doesn’t feel as heavy
Ketamine changes the spines of neurons in the prefrontal cortex
People who are depressed and take ketamine experience separateness from grief and emotions
Take ketamine with psychiatrist guiding experience
Ketamine may be increasing neuroplasticity through dissociative states
Significant improvement in depressive symptoms, mood, and affect in 50-70% of study participants who received psilocybin treatment
Read more: Recent study on the clinical use of psilocybin for the treatment of depression
It’s critical to have a highly trained guide and medical monitoring devices where relevant
There are common themes to psilocybin experience that lead to a therapeutic outcome, but people can have different experiences and still benefit
Microdosing effects don’t seem to be as impactful as bigger sessions given several weeks apart
Ketamine versus psilocybin: ketamine is about dissociating from oneself during the experience; psilocybin is about diving into oneself
MDMA breakthroughs are for trauma, not depression