Tuesday, July 28, 2009

Mother Amygdala, Have Mercy Upon Us

Once upon a time I wanted to be a neurosurgeon. But I had this idiotic fear of science class -- it was in the water that they gave to girls in the 1950s. So I headed in another direction. Still I am fascinated by the brain, and will keep sharing the stuff that I learn about it. Today's topic is the amygdala.

Ah, the amygdala, the reptilian brain. It is among the oldest parts of the human brain, regulating memory, emotion and fear. The amygdala associates a strong emotional reaction with a piece of information to imprint that information in your memory. You remember best what you associate with strong emotion. If you walk under a tree in the tropics and a poisonous snake falls on top of you, it is highly beneficial from an evolutionary perspective to remember that tree where those poisonous snakes linger. That's when the amygdala is your friend.

More immediately, when the amygdala fires up, it sends a message to other parts of the brain for immediate action, fight or flight. Which is a good thing when fight or flight are your two best options, and one or the other is needed immediately. It is not so good later on in the evolutionary process, when you need a third option. There are other parts of the brain that are better at the third option. The anterior cingulate cortex handles anticipation of tasks, motivation to solve problems and modulation of emotional response. The prefrontal cortex also deals with emotion, but adds planning, decision making and deliberate action to the amygdala's fight or flight response. In other words, they provide the third option, and fourth and fifth, and take time to consider which one will work best under the current conditions which probably do not include poisonous snakes, except in a metaphorical sense.

As I said last week, the brains of people with depression work differently than the brains of people who have never been depressed, and particularly these parts of the brain. We have the pictures to prove it. Today's bit of research comes from Hooley, Gruber, Parker, Guillaumot, Rogowska, and Yurgelun-Todd, "Cortico-limbic response to personally challenging emotional stimuli after complete recovery from depression," published in Psychiatry Res. 2009 Feb 28:171(2):106-19.

The authors took fMRIs of twenty-three women, twelve of whom had no history of any mental illness and eleven who had completely recovered from depression and had been in remission for an average of twenty months. [I love these fMRI - functional Magnetic Resonance Images - machines. They take pictures inside the brain, lighting up the parts of the brain are that are active. I can think of a million questions that fMRI's can answer. You will find me referring to them a lot.] -- Anyway, while each woman was being scanned, she was listening to a prerecorded message from her own mother. Some of her mother's comments were positive, some were neutral, and some negative. The negative comments were never new; the daughter had heard them before.

The fMRIs of the never-depressed and the recovered-depressed worked the same for positive and neutral comments, i.e., the same parts of the brain were activated and lit up the image. The negative comments, however, were processed totally differently by the two groups. In those who were recovered, the amygdala went to work on their mothers' criticism, while the prefrontal cortex and anterior cingulate cortex were quiet. The opposite for the never depressed, they processed their mothers' criticism in the prefrontal cortex and anterior cingulate cortex, which told the amygdala that it wasn't needed at the moment.

To put it more simply, those who had been depressed were not running their mothers' criticism through the parts of the brain that process thought, make conscious choices and quiet down emotional responses. Instead, the part of the brain that simply reacts to danger did so, unchecked. The "unchecked" part means that stress hormones would be released, bathing the brain with cortisol, which is known to damage and shrink parts of the brain implicated in depression.

Nevertheless, both before and after hearing the comments, both groups reported the same thoughts and feelings. They gave no indication that their processing was different. The experience of the minds did not match the experience of the brains.

Now how is this for weird: I read "Cortico-limbic response" one morning in June. I visited my mother that afternoon. We were talking about this blog and some fund-raising I had done for NAMI. My mother said something about my work in the area of mental illness that threw me for a loop. Later that evening, still hurting from her comment, I reported it to Helen. Helen got very careful in her language, not wanted to set me off further, "I can understand in your context how that might upset you. But I think it could be understood in a different way that another person might find to be neutral."

Well, unlike the women in this study, I am not in remission. So my mind matched my brain, and I knew that I was upset.

Is remission simply the separation of mind and brain, so that the mind feels just fine, even though the brain behaves as problematically as ever? And if so, is this a good thing?

One might argue that if you don't know you are disabled, you will be less so. Our dog Mazie is an example. Everybody feels sorry for our three-legged dog. From her perspective, she simply lives a life in which a lot of people are gentle and sweet to her, while she runs as fast and as gracefully as she ever did pre-amputation. If the person with the depressive brain can get through the day without symptoms, who would want to argue with that?

Except that it keeps coming back. Which makes me wonder if the forms of treatment we currently have, medication and various forms of therapy, merely mask the damage that the brain continues to experience, like how somebody on morphine can keep walking on a sprained ankle. The pain-killer solves the perceived problem in the short run, but at a cost to the body in the long run. Maybe success in the short view is detracting from motivation to address the long view.

I know a little bit about mindfulness, and am hoping to find out more. I wonder if it might address this issue. That day when I was so upset by what my mother said, it was helpful to me to be aware that my amygdala was at it again. Maybe that awareness helped my anterior cingulate cortex to soothe my amygdala, so it could rest. I don't know, because I don't have an fMRI machine handy for these sorts of questions.

Lately I try to track not my thoughts, but my body when I am in pain. I pray for and to my amygdala for healing.

Is there somebody out there who knows if I am on the right track?

5 comments:

  1. My amygdala is not very helpful, either. When my amygdala goes off, I have found that if I can force myself to think about something, which I suppose engages the prefrontal cortex and tells the amygdala it can stop shouting, I will begin to feel better. Friends can help by starting a conversation about what I think about the price of nuts (but woe the friendly spirit who inquires about how I am feeling!) What works well when I am alone are neuroscience articles about the amygdala and its cousins, which leave me wondering about intricate feedback loops and scientists who don't let their 'sick' patients (aka real people) proofread their articles.

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  2. The bit I got stuck on and keep going back to is "eleven who had completely recovered from depression". It's that "recovered from depression" phrase that seems like an oxymoron to me. Is anyone ever "recovered", or are symptoms just at bay? I want to think about this some more, and talk to a few folks, before saying more.

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  3. Yes, do, and report back. I am coming to the conclusion that except maybe for those lucky one-episode-and-it's-gone folk, depression just IS, and sometimes shows.

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  4. Hello,

    Yes I think you are on the right track. I am constantly concerned that the treatment of both depression and bipolar disorder are symptom-based treatment protocols. I understand that when symptoms are extreme they require immediate reduction (ie in the case of mania). But once the "episode" has passed, then it seems to me time to find "brain friendly" alternatives which would include food choices, certain vitamins, light therapies for depression, certain minerals for sleep (like calcium/magnesium), relaxation techniques, etc. This makes more sense to me because it treats the causes of the problem not just the symptoms of a mal-functioning brain.

    I always take the long view. So I am willing to live with some symptoms of depression because the long term effects of the medications are actually worse than the short term benefits of being "symptom free".

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  5. well that sure explains alot. My perception of my world is not properly filtered.

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