what’s a dopamine reuptake inhibitor? (in layman’s terms)


They say  there is more depression in middle-aged (and older) women. Well now I know why! It’s another part of the body’s aging process. Read on to find out what I found out and what I did about it!

Disclaimer: I am NOT a medical professional. Just a patient who is curious and likes to research my medical issues as they come along. This article is intended to simplify things, and there’s much more involved in the total picture than what I’ve painted here. If you have questions or concerns after reading this post, talk to your doctor!

I had been feeling like I’d “lost myself” for a while. Where was that ‘up’ and  optimistic and happy me? I’d become grumpy and discouraged and not feeling the joy of life. My biggest symptom was that I was more reactive (negatively) to everything and less able to recover from that. In short, I’d begun to notice a significant inability to cope. That was new and scarey for me.

So I went to the doctor. Ya, she gave me some meds. I hate getting meds, especially for the mind. So I did some research and now I understand it all better and I don’t hate my meds. This article might help you understand it better too.

I now consider this particular medication a daily supplement. That’s because I now know it’s replacing chemicals in my brain that are quite normally lost as we get older!

Why don’t I have enough dopamine?
i.e. Why do I need these dopamine reuptake inhibitor pills?

It turns out that I have 30-35% less dopamine than I had in my 20s! Here’s why:

No doctor has said this to me, but after researching to write this article, I’m pretty sure that, for me anyway, the problem is age-based.

  • “It is documented that brain dopamine activity declines with age.” [ref 6]
  • “The loss of dopamine with age is thought to be responsible for many neurological symptoms that increase in frequency with age, such as decreased arm swing and increased rigidity. Changes in dopamine levels may also cause age-related changes in cognitive flexibility.” [ref 8]
  • “The frontal lobes and frontal-striatal dopaminergic pathways are especially affected by age-related processes resulting in memory changes.” [ref 8]
  • “Age is associated with a significant decline in dopamine D2 receptors—molecules that transmit signals that are associated with pleasure and reward in the brain. Approximately 6-7% of these receptors are lost with each decade of age [italics mine] from 20 to 80 years.” [ref 7]

If I do the math on those numbers, I find that now, in my 60s, I have 30-35% less dopamine than I had in my 20s! That certainly tells a story about some of the symptoms that took me to the doctor, resulting in my getting this prescription. My symptoms were a pretty good match to what’s in the table below, under symptoms of dopamine deficiency! Those, plus a notable decline in my “cognitive flexibility” and “memory changes” as mentioned in the quotes above.

Dopamine? Serotonin?

I was chatting with a friend about my new “dopamine reuptake inhibitor” meds, and we got to wondering why some people take those, but others take “serotonin reuptake inhibitors” for seemingly the same reason—feeling some kind of depression or mood problem.

So what’s the difference between dopamine and serotonin? And what do they do for us? And can we figure it out in plain language instead of medical jargon? That’s what I’m going to attempt to do here, mostly for my own understanding, but I’m including you in case you’re wondering too.

“Dopamine and serotonin are two neurotransmitters that are necessary for many aspects of human behavior. Inadequate production and regulation of either neurotransmitter is a cause of many medical conditions.” [ref 1]

Neurotransmitters?

OK, let’s back up for a minute and get some definitions out of the way. I’ll try to do this in my own words and maybe help de-code the medical terminology we find online, put it into some plain English.

Neuro means it has something to do with the body’s nervous system or system of nerves. This sytem is our body’s ‘information highway’, transmitting information signals from one part of the body to another, one cell to another. In this case, we’re talking about the brain’s nerve cells….. i.e. neurons.

Neuron is the name for nerve cells in the brain. A neuron has a very specialized purpose—processing and then conducting nerve impulses (signals) from itself to another neuron. Neurons must communicate with each other to get those signals to where they’re needed in the various parts of our brains. Neurons don’t touch each other; they have to communicate across the gaps between them….. i.e. synapses.

 A synapse is the very small gap between neurons. Nerve signals zap across the synapse. How do they do that? The signals are carried by electrochemicals called….. neurotransmitters.

 A neurotransmitter is one of a number of natural chemicals we have in our bodies that transmit signals from one nerve cell to another. Just as hormones control many body functions, neurotransmitters control various brain/nervous system functions. The neurotransmitter chemicals function as a kind of liquid FedEx truck, carrying signals from one neuron to another across a synapse. In this article, we’re discussing only two neurotransmitters: dopamine and serotonin.

Neurotransmission

**See the 2 short videos below, but finish reading this section first to better understand what’s happening in them.

So to over-simplify (i.e. neurons aren’t round balls with labels in them; synapses aren’t chasms but extremely narrow gaps, neurotransmitters and the nervous system are way more complicated than I’m describing, but anyway….), I have a picture in my imagination, like my little drawing here. Two neurons need to talk to each other about some important nervous-system information, but they can’t touch or even reach each other across the synapse gap. They  have to send the signals some other way. So they package the signal up within a kind of soup of chemicals (neurotransmitter soup, LOL) that is specially made for the sole purpose of carrying those signals from one neuron to another across the synaptic gap. Then they shoot that signal+neurotransmitter soup outwards…..

The signal-sending nerve cell (a.k.a. presynaptic cell) has an axon, which is like a long, slender fiber extending out from the nerve cell. The outgoing signal, packaged up in its neurotransmitter soup, travels along the axon and is then released into the synaptic gap.

The signal-receiving (receptor) nerve cell (a.k.a. postsynaptic cell) has small branch-like appendages called dendrites that capture the signal and pull it into the receiving neuron. To imagine dendrites, imagine the tiny, underdeveloped twigs that fan out at the end of a leafless tree branch. The receptor cells are covered with dendrites, all poking out from the cell into the synaptic neurotransmitter soup.

Reuptake: This is the last phase of the signal transmission process. After the signal has been sent and received, the presynaptic cell (the one that sent the signal) has to clean up after itself. That is, it has to reabsorb the neurotransmitter chemical, which is too plentiful and dense to just diffuse. And also because the neurotransmitter chemicals can be reused by the cell for future signals. “Reuptake is necessary for normal synaptic physiology because it allows for the recycling of neurotransmitters and regulates the level of neurotransmitter present in the synapse and controls how long a signal resulting from neurotransmitter release lasts.” [ref 2]

Reuptake inhibitor: This is a descriptor for a certain class of meds, most commonly prescribed as antidepressants. From the above information, you know what reuptake is. These meds prevent that last “cleanup” step (reuptake). The result is that more of those neurotransmitter chemicals remain in the synapse gap on an ongoing basis. This facilitates continued (and better) neurotransmission of signals across the synapse. The specific/actual effect of this varies with the various neurotransmitters we have. Different meds target different neurotransmitter chemicals. So, for example, if my doctor prescribes a “dopamine reuptake inhibitor”, then dopamine is the only neurotransmitter chemical it works with.

Animated video (just 1.5 minutes)

3D Animation: Neurotransmitter Synapse (1 minute; amazing!)

The difference between dopamine and serotonin?

Simply put, they are both neurotransmitters found naturally in our bodies, but they reside in and act on different parts of our brain.
(Serotonin also resides in and works from our intestinal tract, but I’m not talking about that here.)

SEROTONIN DOPAMINE
produced where in the brain? by neurons in the brain stem by neurons in the basal ganglia, which is higher up in the brain
regulates what parts of the nervous system? conscious awareness; screening out of extraneous stimuli; managing the sleep/wake cycle [ref 1] movement; learning
[ref 1]
how does it affect us? motivation, pleasure-seeking behavior, voluntary movement, reward, cognition, attention, learning & problem-solving, mood, temperature, muscle contraction, cardiovascular & endocrine systems.“When we have enough serotonin, we feel emotionally stable, we can sleep, we can sort out feelings and determine in a logical manner if there is a threat present.” [ref 5]
….
Note: “Serotonin acts a bit differently on each individual, making it a challenge to ascertain its precise effect on mood.”
[ref 4]
mood, appetite, sleep, memory, learning, emotional arousal, reward system, social skills“Dopamine is often called the ‘Feel Good Neurotransmitter’. When we have enough Dopamine we have:
-feelings of pleasure
-feelings of attachment/love
-a sense of altruism (unselfish concern for the welfare of others)
-integration of thoughts and feelings”
[ref 5]
symptoms of excess? [ref 4]  results in “serotonin syndrome”, characterized by shivering, diarrhea, muscular rigidity, fever, and seizures uncontrollable movements such as tremors, twitches, repetitive tapping or jerking movements,  increased pulse rate and blood pressure from increased strength of contractions
symptoms of deficiency? [ref 4]  anxiety, depression–with accompanying feelings of unworthiness and difficulty concentrating, fatigue, sleep and appetite disorders. Premenstrual syndrome and bulimia can also occur fatigue, lack of motivation, depression, difficulty initiating and controlling the trajectory or precision of muscle movement

Why can’t I just take dopamine pills?

The answer is simple: You can’t take dopamine tablets, because dopamine is not able to pass from your bloodstream into your brain. As they say in medical terminology, it can’t cross the blood-brain barrier.

So we’re left with taking dopamine reuptake inhibitors to increase the amount of dopamine that gets left in the synapse, where cell communication takes place. (Or in cases of specific diseases like Parkinson’s, there are other pill-helpers called dopamine agonists that can get into your brain, where the medicine/chemical is changed into dopamine by your brain cells and then affect the brain the same way as dopamine does.)

Can I increase my dopamine without taking pills?

Some online authors say we can do this with various foods and supplements (avoiding some, increasing others, etc.) They all pretty much agree on which items help, so I’m just going to provide a few links for you about this:

Update: 3-month checkup…

I am back to feeling my happy, optimistic, go-with-the-flow me. When I went for my 3-month followup, my doctor (who didn’t know I’d been researching all of this) said that depression might come and go as I get older. She said there’s absolutely no harm in continuing to take the dopamine reuptake inhibitor for as long as I want. For the rest of my life if I want.

So I’m going to give that a try. I mean, if my body is betraying its youth by reducing the dopamine in my brain, I’ll show it a thing or two! I’ll work with that new knowledge rather than fight it.

Update: 20 months later…

Still taking the dopamine reuptake inhibitor. I definitely have my Self back and it’s SO much healthier not being depressed. Duh!

So for me, that pill has become simply a supplement I take daily with my other supplements.

Sure, I have my low days like everybody else. But I’ve regained my ability to bounce back in a reasonable period of time… of course, that’s after the requisite hours of self-indulgence, self-care, some exercise, some Haagen Dazs, whatever the booster-of-the-day is.

In short, after 20 months, I really do believe in this research I’ve explored. I really do believe that acknowledging and addressing our brain’s chemical changes helps us address at least one component of depression: It helps us eliminate the self-blame aspect, which helps us get on with our return to Joy!

References:

1. Dopamine vs. Serotonin
http://www.ehow.com/facts_5575149_dopamine-vs-serotonin.html

2. Reuptake (wikipedia)
http://en.wikipedia.org/wiki/Reuptake

3. Neurotransmitter (wikipedia)
http://en.wikipedia.org/wiki/Neurotransmitter

4. Dopamine vs. Serotonin
http://www.livestrong.com/article/175158-dopamine-vs-serotonin

5. Neurotransmitters
http://www.squidoo.com/n
eurotransmitters

6. Association Between Decline in Brain Dopamine Activity With Age and Cognitive and Motor Impairment in Healthy Individuals
http://ajp.psychiatryonline.org/article.aspx?articleid=172737

7. How Aging Affects Brain Chemistry
http://www.bnl.gov/bnlweb/pubaf/pr/2000/bnlpr010400.html

8. Aging Brain
http://en.wikipedia.org/wiki/Aging_brain#Dopamine

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