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The Neurobiology Of Depression

Updated on March 31, 2010
Is it February the second or the third?
Is it February the second or the third?


Okay! Let’s begin. It could be depressing or exciting. What will it be? Let’s, for fun, MAKE it exciting.

The other day, I was listening to Wayne Dyer’s book, Change Your Thoughts Change Your Life. He invited the listener to move his index finger or wiggle her toes and then to notice how effortless it is to do. For a long moment, I became very conscious of the process. I could not feel the message from my brain to my index finger or toes, but I was conscious of the message and even more amazed how quickly the message made it from my brain to my finger and toes. In fact, more than quickly. In NO time. That’s an interesting phrase. Yes, my consciousness of the process lagged behind the process itself. Amazing.

So the brain is obviously intricate and complex. But there is a way to get a "simple" but accurate understanding of what goes on in our brain. I’m sure we have all had any number of big people in our lives tell us that there is nothing going on inside our brains, but it just isn’t true! There’s a LOT. Yea, those big people tell us all kinds of things that just are not true! What’s up with those big people?!

Basically, the way the brain works is like this. We take in information through our sensory organs. This information then goes directly to our THALAMUS which is located in the midbrain. The thalamus then actually "decides" what information to send on.

The implication here is that we are perceiving a lot more information than we ever have consciousness of. It’s like taking a picture with a digital camera, and then zooming in on the background and to each side of the picture. There is MUCHO "stuff"–information–in the background and to the sides of the picture, far more than we can see in the "finished" picture, far more than we were aware of when we "snapped" the "shot." Wow, we have such interesting words and phrases!

So the Thalamus sends the information that it "decides" to send, to both our thinking brain and to our emotional brain. The thinking brain consists of all the lobes of the CEREBRUM which is sometimes referred to as the top brain. When you see a picture of the "outside" or "top" of the brain, it looks like a bunch of curly cues or worms!

An important region of our thinking brain is the PREFRONTAL LOBE which is located basically just above our eyebrows. It is here that we have consciousness of consciousness. It is here that we are able to slow down or stop our impulses and make good decisions.

The emotional brain is often referred to as the LIMBIC SYSTEM or the mid brain. You could also say it’s the "inside" of our brain. When the thalamus sends the information to our emotional brain, it heads directly to our AMYGDALA which gives emotional significance to our experience. The amygdala instantly sends a message to our muscles, and we experience this message as FEELINGS. The feelings move our muscles either toward or away from the experience. Thus sometimes emotions or feelings are called BIOLOGICAL MOTIVATORS.

Now if we take the time to talk about or "debrief" an intense emotional experience, the experience will be stored in our hippocampus and become part of our long term memory. A week later, we will know that this intense emotional experience happened last week or last month, or ten years ago. BUT, if for some reason, we do not talk about or debrief the intense emotional experience, then the emotions associated with the experience remain "stored" in the amygdala. If, in the future, the amygdala "sees" another intense emotional event which appears even remotely similar to this one, it will fire off the already stored intense emotions. We experience this firing as a reaction or over reaction. We get confused because it appears that our intense feelings are connected to what is occurring at the moment, but typically the emotions are associated with an "old" emotional experience that was never debriefed.

Now there is an on-going neuroelectric and neurochemical conversation between our thinking brain and our emotional brain. These conversations create connections or neuropathways between various places in our brain. These neuropathways contribute to the creation of mental models which are stored again in the amygdala. These mental models are created from repetitive experiences. For example, I have a mental model that says fire trucks are red. When I see a green or white or yellow fire truck, I literally slow down in the car to check out to see if this is a fire truck or not! Apparently, I am the only one in Southern California with a mental model that says fire trucks are red, because when I slow down to check out a green, white, or yellow fire truck, and then glance in my rearview mirror, I notice an angry line of cars stacking up and practically crawling over my rear bumper!

Our BRAIN STEM is yet another part of our brain. It is at the base of our brain and connects to our spinal chord. The brain stem is sometimes called our SURVIVAL BRAIN because it constantly monitors things like heart rate, blood pressure, blood sugar, and the myriad of other brain and bodily functions that contribute to our survival. When the brain stem sees that survival is at risk, the brain stem literally takes over the functioning of our brain and stops the conversation between the thinking brain and emotional brain. We act in auto pilot mode and whatever it is we do to survive that moment, the brain will then store as a resource for the next time we are at risk. Unfortunately, the brain stem cannot assess if what we did to survive was really helpful or not. We could be half dead, but nevertheless alive, and so the brain stem says, in effect, "Oh goodie, we’ll save that strategy for the next time we are at risk."

Again, it is important, that any time we go into survival mode, to return to the "scene" to debrief the experience, to see if what we did to survive is actually helpful. It may be that what we did was NOT helpful at all, so we will need to plan out a new survival strategy.

So now you can understand why on-going training for folks who work in high risk jobs is so critical. And why when we lose it with a partner, a friend, or a child, we need to debrief, even if we are FEELING justified, feeling like we saved our life or saved face, perhaps in the process, we killed the relationship or the other person's spirit.

You will find a somewhat more detailed overview of how our brain works in my blog HOW OUR BRAIN WORKS .

So what does all of this have to do with depression? The limbic brain, in sync with other neuro processes, regulates arousal, sleep, appetite, and the experience of pleasure–all the elements of being depressed or not. This regulation is part of that on-going neuroelectric and neurochemical conversation referred to above. When we begin to experience stress, and with the experience comes an increase in stress hormones, a delicate feedback loop comes on line, so to speak. This feedback loop involves the hippocampus and the prefrontal lobe. The delicate neurochemical feedback loop literally provides us with the ability to both control our stress, our thoughts about the stress, and most impotantly our subsequent decisions about our behavior. How am I going to respond (in contrast to react) to the stress?

For example, a car cuts me off on the freeway. This neurochemical connection between our hippocampus and prefrontal lobe allows me to decide to slow down, stay calm, let the guy (or gal!) go, or if he seems to be a threat to other drivers, to take down his license number and call it in. But if this delicate balance gets tipped, because of an over abundance of stress hormones, the level of the neurochemicals necessary to "run" that delicate feedback loop are insufficient. Wow!

We also know that, when the brain stem notices increased levels of stress hormone in our blood stream, it begins to take control of our brain which eventually means shutting down the "conversation" between the thinking brain and the emotional brain. When that happens, that delicate feedback loop between the hippocampus and the prefrontal lobe that decreases stress and enhances thinking becomes inoperative. Our amygdala may also begin to fire at will flooding us with intense emotions that are all coming from old experiences. Since the conversation between the thinking brain and emotional brain is shut off, we have no way to make any good sense out of the emotional flooding except that life is doing awful things to me.

Now once the brain stem takes over, it takes a minimum of twenty to twenty-five minutes for our brain chemistry to get back to "normal." This is why it is important, when we are flooded, to have a preplanned safe way to take a time out. The same for couples when they are fighting. Once their brain stems take over, the only way back to a sane conversation is a timeout for twenty to twenty five minutes minimum. The next day might be even better! Something to be said for sleeping on it!

If we learn effective stress management skills, there is a very small window of opportunity between the brain stem being on alert and then completely taking over. Stress management teaches us how to use this small window. The simplest thing we can do is yoga breathe which will increase the oxygen levels in our brain and balance out the increased levels of stress hormones. It seems simple, and it is, but the "rush" into survival mode is so powerful, almost addictive, that it is not easy to yoga breathe and push back against the rush.

Research seems to indicate that depressed and suicidal folks have deficient levels of the neurochemicals necessary to run that delicate feedback loop between the hippocampus and the prefrontal lobe described above. Wow! We are also learning how some antidepressants seem to support that feedback loop and some not.  If you want a little more detailed information here, but still simple, check out the following.

So what do I make of all of this?

Well, it is important for me to acknowledge who I am NOT. I am not a neurologist, I am not a medical doctor, and I am not a pharmacologist. I am a licensed psychotherapist and have been in practice for almost 28 years. I sit with depressed people every day. I have my own share of depression from my own life. And, just in case your wondering, I seek out lots of support from colleagues so that the client’s depression doesn’t pile on top of my own and my office doesn’t begin to appear as a new mountain in the landscape. The tour guide says, "And now folks we are passing what used to be Vern’s office. It is now Mount Depression."

For about twenty years now, I’ve been trying to comprehend how the brain works and feed it back to folks in a way that is perhaps oversimplified, but nevertheless comprehensible, but more importantly HELPFUL. Helpful in being able to contribute to one’s healing and moving through depression.

I might also add that depression is not necessarily a bad event. It is, in fact, a necessary outcome of loss. The body itself MUST go through depression in order to effectively grieve a loss. Obviously, depression becomes challenging, perhaps problematic, when we get stuck in it. It’s like the horse in the swamp of sadness in the movie, The Never Ending Story. That is a terrible scene, very disturbing for me.

So when I think about these neurochemical and neuroelectric conversations going on between the thinking brain and the emotional brain, when I think about that particular feedback loop between the hippocampus and the prefrontal lobe that helps us with stressful events, or when that feedback loop gets eliminated because of an abundance of stress hormone, when I think about the role of the hippocampus in long term memory and how the chemistry necessary for long term memory processing is neutralized by an overabundance of stress, I come up with an image that perhaps can shift or opens up some of the mystery around the neurobiology of depression.

When I’m depressed, my life becomes like the movie Groundhog Day. Whatever is over-the-top stressful today or whatever is over-the-top depressing today, it NEVER goes away chemically. Since it does not go away chemically, the facts are almost irrelevant. My brain and my body still feel stressed and depressed. The amygdala is still sending stressful and depressing feelings to my muscles. So I end up making one of two statements. "I don’t know why I am depressed. Nothing happened today to make me depressed," OR "EVERYTHING that heppened today IS depressing and stressful." Someone could show me facts that prove that nothing depressing or stressful happened today, but the facts cannot convince the messages being sent to my muscles.

I wake up every morning and it is still February the second, the day I got depressed or over stressed. The repeated experience of life being depressing and stressful creates a mental model. Just like fire trucks are red, life is stressful and depressing. Our mental models are a testimony to our brain’s drive to make sense out of every life experience.

Since I’m always "viewing" life through the shroud of depression, what I see are distortions. Distortions lead to a level of paranoia. Eventually, my entire day-to-day experience of living translates into LIFE IS AGAINST ME. The title of a humorous but informative book says it all. Maybe Life Just Isn’t That Into You.'s-Just-Not-That-Into-You/Martha-Bolton/9781582296593

For me, making sense out of the neurobiology of depression as being stuck on ground hog day, relieves the hopelessness of being genetically stuck, erases the judgment of being too lazy to get out of the depression, it shifts my experience of myself from being a walking diagnosis, crazy, awful, bad, worthless, hopeless, selfish (and the list goes on, judgments from both myself and others), to a person who deserves waking up on February the third. Say it outloud. I DESERVE TO WAKE UP ON FEBRUARY THE THIRD.

For some, it may seem almost impossible to wake up on some other day than February the second, much as it did for Bill Murray in the film. And there are numerous treatment modalities, and some times they are most effective when implemented together, for example both psychotherapy and psychopharmacology.



Sunrise or sunset?
Sunrise or sunset?


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    • kimh039 profile image

      Kim Harris 7 years ago

      Hey Vern, maybe we should put our comments together to make a blog! We've got about 222 words now.... a good start. It is hard to read all the really good articles here!

    • vrbmft profile image

      Vernon Bradley 7 years ago from Yucaipa, California

      Thanks Kim for reading. I know from your blogs that you are interested in how our brain works. It's hard sometimes to talk about the brain and forget that I'm talking about myself! When I talk about the brain at a workshop, I use the anallogy of the microwave. We know the microwave is working, but we never actually see the microwaves. I tell people if there is anyone who actually sees the microwaves that they need some medication! Altho, I guess I might be overlooking that some very INSIGHTFUL God-gifted person might actually be able to see them!! I appreciate you reading and commenting. It is a challenge for me to keep up with everyone else's blogs!! Yea, kind of impossible, but I want to at least make an effort for those who support me. So I really appreciate you reading two at one time! AND thanks for the new info and link

    • kimh039 profile image

      Kim Harris 7 years ago

      I like how you explained neurobiologically why it's important to examine significant emotional events and stressors. And I find it comforting, at times, to know that my brain picks up on details that I'm not conscious of. Gavin de Becker explains it well in his book, The Gift of Fear: And Other Survival Signals that Protect us from Violence. I'd attach an audio clip here if I knew how....which I probably do. I'm just not aware that I know it yet! This might work:

    • vrbmft profile image

      Vernon Bradley 7 years ago from Yucaipa, California

      When you finally woke up on February the third, it made sense! So maybe coffee and a smoke is the answer! Thanks so much for reading and especially for going back and reading it for a second time!

    • palmerlarryray profile image

      Larry Ray Palmer 7 years ago from Macon, Missouri

      Great Post Vern... I had to read it twice because I was half awake the first time and I just said "Huh?" but now a cup of coffee and a smoke later, it all makes sense.

    • vrbmft profile image

      Vernon Bradley 7 years ago from Yucaipa, California

      Thanks for reading, Terri. I thought Mount Depression was pretty funny! Glad the blog unblogged some things for you!

      Take care

    • profile image

      Teresa Huerta 7 years ago

      Hi Vern. now it makes sense to me how things compile up and eventually we just have a melt down. How many times have I over loaded myself emotionally and after awhile my body psycially ..reacts your articial makes perfect sense ... and I loved the depressed mountain and from the history of your place itself could need a bit of defusing or if the walls could talk...the roof might fall in! love you