Dopamine,
Methamphetamines, and You
What does dopamine do anyway?
How do brain chemicals like Dopamine work?
This is your brain on Meth!
How can the brain ever be normal again?
What about the receptors that were destroyed?
Are there any medicines that can help?
First things first -- What does
dopamine do anyway?
1) Dopamine is critical to the way the
brain controls our movements. Not enough dopamine -- can't move, or
control our movements well. Too much dopamine?
Uncontrollable/subconscious movements (like picking, tapping, repetitive
moments, jerking, twitching). Remember that the heart is a muscle, too,
and too much dopamine will result in increased pulse and blood pressure.
2) Dopamine controls the flow of information from
other areas of the brain, especially memory, attention and
problem-solving tasks. This becomes important when we talk about
amphetamine-induced psychosis that is common in meth abusers.
3) When dopamine is released it provides feelings
of enjoyment and reinforcement to motivate us to do, or continue doing,
certain activities. Dopamine is released by naturally rewarding
experiences such as food and sex. This pre-programmed reward system
makes sure that people do eat, do desire to procreate, and basically
survive. Without enough dopamine, people feel the opposite of enjoyment
and motivation -- they feel fatigued and depressed, and experience a
lack of drive and motivation.
How do brain chemicals like
Dopamine work?
Brain chemicals, including Dopamine, are
stored in cells, which you can think of like barrels full of that
chemical. When something occurs like a good meal or great sex the brain
pours out some dopamine from the dopamine barrels into an open space in
the brain called a synapse. It floats around there. Think of the synapse
like a street, and dopamine is like little cars driving around aimlessly
on the street.
Across the street (not far) from the barrels of
dopamine are Dopamine receptors. These receptors have little parking
spaces on them that only fit Dopamine (or a substance VERY similar in
chemical shape to Dopamine) into them, like a lock and key. As the
Dopamine floats around in the synapse, it finds parking spaces at
Dopamine receptors, and "plugs in" to the receptors. THIS is the point
where we feel good, when the Dopamine is parked in a receptor's parking
space. There are, however, a limited number of receptors with "Dopamine
only parking" available, and each receptor has a limited number of
parking spaces. So some of the dopamine may not be able to find a place
to park.
When all the parking spaces are taken, the
remaining dopamine that didn't find a place to park is normally
recycled. There are "reuptake molecules" that do this -- think of them
like tow trucks. They find the extra dopamine, and tow it back to the
barrels of Dopamine so that it can be re-used the next time. After some
time has passed, the receptors release the Dopamine that was parked in
their parking spaces, and the tow trucks take those Dopamine molecules
back to the barrel too.
The brain has a safety-check system that will
destroy any excess Dopamine that isn't in a parking space, and didn't
get picked up by the tow truck. There are special chemicals in our
brains that will break down this extra dopamine. Think of this like the
toxic waste crew coming in and sweeping up the street.
As a last resort, after repeated long-term
over-stimulation, the brain will shut down Dopamine receptors so that
nothing can park there ever again. Think of this like the demolition
team coming in and permanently barricading off the driveways.
This is your brain on Meth!
So now that we have a basic understanding
of how things work normally, I'll try to explain how things work when
meth is ingested.
When someone eats, snorts, injects, or otherwise
gets meth into their system, meth stimulates those barrels of Dopamine
to pour out Dopamine. Meth continues to tell the cells to pour out
dopamine until the body can break down the meth, which is typically 12
hours or so.
So Dopamine is poured out into the synapse
(street) and finds parking spaces at dopamine receptors and makes the
user feel high.
But meth is a tricky little chemical. It is shaped
closely enough to Dopamine that the tow trucks get confused, and pick up
meth thinking that it is dopamine. So the tow trucks are busy driving
around hijacked by meth molecules leaving the extra Dopamine molecules
floating around in the street (synapse). Well... that means the toxic
waste crew comes in and destroys that dopamine that did not get
recycled. So for the 12 hours or so it takes for the body to break down
the meth, it is also spending that time destroying dopamine.
As long as the user keeps ingesting more meth,
this process continues until there is not enough dopamine left to feel
high from. When the user finally stops using, and the brain breaks down
the meth molecules, the recycle trucks try to salvage what dopamine
there is left, while the user crashes.
The end result of a "run" or "binge" on meth is a
marked decrease in the amount of dopamine left in the brain. This leaves
the user feeling exhausted, hungry, depressed, possibly suicidal and
definitely unmotivated. They are literally suffering from a brain
chemical imbalance. Self-inflicted mental illness.
How can the brain ever be
normal again?
Well, luckily, the human body is pretty
resilient. We do have the ability to make replacement dopamine. However,
the body was not designed to need to do this in large quantities or in
quick supplies. So we don't have a mass-production plant making
dopamine. It's a 3 to 4 step process, too.
The process: Phenylalanine --> Tyrosine -->L-dopa
--> Dopamine
Phenylalanine is the first "pre-cursor". It can be
found in the following foods: soybean protein, frozen tofu, dried and
salted cod, shellfish, lean meat, organ meat, skin-free chicken, cheese,
milk, eggs, many seeds (watermelon, fenugreek, roasted soybean nuts),
and chocolate. Equal artificial sweetener also contains Phenylalanine.
The body can turn Phenylalanine into Tyrosine.
Tyrosine can also be found in food. This would
eliminate the need for the body to synthesize it from Phenylalanine. One
step closer to dopamine! Meat, dairy, eggs as well as almonds, avocados
and bananas are good sources of Tyrosine.
From there, the body will convert Tyrosine into L-Dopa,
and then on to Dopamine (and other neurotransmitters like norepinephrine).
So... to replace dopamine destroyed while high on
meth, the recovering user must eat sources of Phenylalanine or Tyrosine.
To aid the body in making Dopamine, the person can
use what dopamine they DO have left as often as possible. This tells the
body that they need more of it. While you sleep, you use very little
dopamine. Exercising, even just a walk around the block will use
dopamine (remember, it controls movement). So setting a reasonable sleep
schedule, and trying to get some exercise will help speed up recovery
from Self-inflicted Dopamine Destruction (aka meth addiction)!
Be patient -- remember, we weren't designed to
waste dopamine, we were supposed to be recycling it. The process of
replenishing dopamine takes months. Studies show that recovering meth
addicts who have abstained from meth use have about 80% of normal
dopamine levels after 18 months of abstinence. This WILL be a long
battle. It CAN be won.
What about the receptors that
were destroyed?
Well, good news again. Even though those
receptors can never heal or recover, the brain is able to use existing
receptors and find new pathways to accomplish the same results. Some
receptors will even get a home equity loan and build on extra parking
spaces!
Are there any medicines that
can help?
A doctor should always be consulted and
included on any medication treatment for a recovering user. Many
recovering addicts have found Wellbutrin (Bupropion) to be helpful after
a few months of clean time. What Wellbutrin does is block some (not all)
of the tow trucks for a little while so that the dopamine the person has
left can be more effective. It does not, however, stimulate the barrels
to pour out dopamine. The person has to have enough dopamine in their
brain before Wellbutrin can help.
Health stores do carry supplements of
Phenylalanine and Tyrosine. A recovering addict who finds it difficult
to eat enough protein may benefit from a supplement. Again -- consult
your doctor first.
Lori Pate
B.A Psychology
University of Texas at Austin
Disclaimer: I am not a
medical doctor and this page was not intended to provide medical advice.
Other articles by Lori Pate:
Triggers to use drugs
When there
is more than meth going on
Meth and
Metabolism
The Brain Chemistry of Being a Loved One
Back to Crystal Meth & Methamphetamine Questions, Answers & Advice
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