Effects on the Brain
Dr. Kathie F. Nunley
There has been an abundance of research released over the past
18 months shedding new light on an old problem --the effects
of tobacco, alcohol and other drugs on the central nervous system.
Perhaps fueled by funds available through tobacco settlement
monies, we see a particular increase in the amount of nicotine
Three main themes arise. First, all drugs effect the brain -
some very substantially, particularly in adolescents. Second,
the plasticity of the brain and its amazing ability to compensate
for change, can lead to drug-crippled brains. Thirdly, certain
neurons appear to be more resilient than others to drug effects.
Most drugs (cocaine, alcohol, etc.) tend to work by increasing
dopamine levels in the amygdala and other pleasure regions of
time a substance significantly changes a neurotransmitter (nerve
cell communication chemicals), it will cause damage with chronic
use. The reason for this is the brain's inherent need and ability
to repair its own systems.
what's going on. Think of a pleasant experience (a romantic
evening, sunbathing on the beach, a double decker hot fudge
sundae....). Feel the pleasure? What you are biologically doing
is secreting dopamine, a major brain chemical, into the amygdala
region of your brain. Receptor sites (dopamine doorways) open
up to receive the chemical and cause that pleasure part of your
brain to fire. It is nice, isn't it? That's what most drugs
do, only on a much more intense basis. They cause huge amounts
of dopamine to flood into the amygdala region.
problem comes with repeated use. The brain is efficient and
self-correcting. So once you start providing this intense serge
of dopamine on a regular basis, the brain tries to compensate
for the disturbance by either reducing production of dopamine
or locking and removing dopamine receptor sites. (The brain,
as living tissue, makes no value judgment on whether the feeling
was good or bad, it is just seeking to correct an imbalance
you have created). Now you have established tolerance. This
means a person will have to use more of the drug to get the
same effect because the brain has reduced its own production
and limited the dopamine doorways or receptor sites.
Imagine what happens after long-term chronic use. Natural production
of the neurotransmitter has all but been shut off as the brain
realizes it is being provided artificially, so doesn't need
to waste energy producing it on its own. Receptor sites or avenues
for the neurotransmitter to attach in the brain have been limited
and severely reduced in the brain's attempt to reduce the overactive
region. The brain has now become crippled. It essentially has
lost its natural ability for pleasure. The drug addict who is
attempting to withdraw, is faced with a pleasure center that
doesn't work. Not only does the brain not produce dopamine in
natural quantities, it has removed many of the receptor sites
or doorways in the pleasure regions.
drug-free addict will feel no pleasure in imaging a candlelight
dinner, sunbathing on the beach, or even eating a double decker
hot fudge sundae. What has been created is a brain which can
feel no pleasure in anything unless done through artificial
means. It is easy to see how life would not feel worth living
and why the suicide rate during recovery is so high and successful
recovery rates are so low.
major effect of various drugs on the brain is the actual deterioration
of brain nerve cells. Alcohol, nicotine, cocaine and ecstasy
all are known to degenerate gray matter, and thereby reduce
the volume of some key brain regions. This loss can cause processing
problems in many of the decision-making areas of the cortex
as well as interfere with memory systems. Research is now even
showing that different aged brains are affected in different
ways. For example, it has been shown that alcohol reduces the
volume of the hippocampus in adolescent brains, but apparently
not in adult brains. The reduction is more severe in teens that
start alcohol use early and often. The hippocampus is responsible
for processing new information into memory.
Drugs do not affect all brain cells equally. There are two main
types of neurons in your brain. Fatty and plain. Some nerve
cells are covered in a fatty layer called a myelin sheath. These
cells are able to transmit electrical signals ten times faster
than than the uncoated neurons. The fatty covering lends a somewhat
whitish appearance to the cells, hence the name white matter.
Gray matter would be composed of unsheathed or plain neurons.
When nerve cells in the brain are damaged from drugs, it tends
to be the gray matter rather than the white. This would indicate
that the myelin sheath may offer some protection against chemical
there any "safe" drugs? Biologically speaking, it doesn't appear
so. It seems the brain's natural healing powers and compensation
skills can turn into our own worst enemy where drugs are concerned.
Obviously the brain's ability to move into that compensation
mode varies from person to person and it seems that those with
the systems quickest to adjust are the brains most likely to
there is any good news to this story it could come from the
pharmaceutical industry which is looking for some type of recovery
aid for addicted brains. There is hope that medicines may become
available to help persons through their recovery by helping
the brain heal faster, restore receptor sites sooner or restore
dopamine production. Until then, the only hope for the addicted
brain is time and continued research.
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Dornbusch, Sanford M.; Lin, I- Chun; Munroe, Paul T.; Bianchi,
Alison J. International Journal of Adolescent Medicine &
Health. 1999 Jul-Dec Vol 11(3-4) 197-219
The association between cigarette smoking and drug abuse in
the United States. Lai, Shenghan; Lai, Hong; Page, J. Bryan;
McCoy, Clyde B. Journal of Addictive Diseases. 2000 Vol 19(4)
3. Anabolic androgenic steroids affects alcohol intake, defensive
behaviors and brain opioid peptides in the rat. Johansson, Pia;
Lindqvist, Ann-Sophie; Nyberg, Fred; Fahlke, Claudia. Pharmacology,
Biochemistry & Behavior. 2000 Oct Vol 67(2) 271-279.
Age-related brain volume reductions in amphetamine and cocaine
addicts and normal controls: Implications for addiction research.
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Chronic cocaine treatment induces dysregulation in the circadian
pattern of rats' feeding behavior. Giorgetti, Marco; Zhdanova,
Irina V. Brain Research. 2000 Sep Vol 877(2) 170-175
Selective neurotoxic effects of nicotine on axons in fasciculus
retroflexus further support evidence that this a weak link in
brain across drugs of abuse. Carlson, Janice; Armstrong, Brian;
Switzer, Robert C., III; Ellison, Gaylord. Neuropharmacology.
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Running and cocaine both upregulate dynorphin mRNA in medial
caudate putamen. Werme, Martin; Thoren, Peter; Olson, Lars;
Brene, Stefan. European Journal of Neuroscience. 2000 Aug Vol
Subacute onset of oculogyric crises and generalized dystonia
following intranasal administration of heroin. Schoser, Benedikt
G. T.; Groden, Christoph. Addiction. 1999 Mar Vol 94(3) 431-434
Self-administration behavior is maintained by the psychoactive
ingredient of marijuana in squirrel monkeys. Tanda, Gianluigi;
Munzar, Patrik; Goldberg, Steven R. Nature Neuroscience. 2000
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Memory disturbances in "Ecstacy" users are correlated with an
altered brain serotonin neurotransmission. Reneman, Liesbeth;
Booij, Jan; Schmand, Ben; van den Brink, Wim; Gunning, Boudewijn.
Psychopharmacology. 2000 Feb Vol 148(3) 322-324.
Brain atrophy and neuronal loss in alcoholism: A role for DNA
damage? Brooks, P. J. Neurochemistry International. 2000 Nov-Dec
Vol 37(5-6) 403-412.
The influence of glycine on EEG parameters and sensorimotor
activity in normal and alcoholic subjects. Mashkova, V. M. Human
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Alcohol enhances characteristic releases of dopamine and serotonin
in the central nucleus of the amygdala. Yoshimoto, K.; Ueda,
S.; Kato, B.; Takeuchi, Y.; Kawai, Y.; Noritake, K.; Yasuhara,
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Hippocampal volume in adolescent-onset alcohol use disorders.
De Bellis, Michael D.; Clark, Duncan B.; Beers, Sue R.; Soloff,
Paul H.; Boring, Amy M.; Hall, Julie; Kersh, Adam; Keshavan,
Matcheri S. American Journal of Psychiatry. 2000 May Vol 157(5)
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alcoholics: Sex differences. Moussas, G. I.; Dadoutis, G.; Botsis,
A.; Lykouras, L. Psychiatriki. 1999 Jul-Aug Vol 10(3) 228- 235
Suicidal ideation among college students in the United States.
Brener, Nancy D.; Hassan, Sohela Sabur; Barrios, Lisa Cohen.
Journal of Consulting & Clinical Psychology. 1999 Dec Vol
Auditory and visual event-related potentials in alcoholics:
Abnormalities of components and brain electrical field. Olbrich,
H. M.; Maes, H.; Gann, H.; Hagenbuch, F.; Feige, B. European
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"Loss of control" in alcoholism and drug addiction: A neuroscientific
interpretation. Lyvers, Michael. Experimental & Clinical
Psychopharmacology. 2000 May Vol 8(2) 225-245.
Marijuana, alcohol and actual driving performance. Ramaekers,
J. G.; Robbe, H. W. J.; O'Hanlon, J. F. Human Psychopharmacology
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F. Nunley is an educational psychologist, author, researcher
and speaker living in southern New Hampshire. Developer of the
Layered Curriculum® method of instruction, Dr. Nunley has
authored several books and articles on teaching in mixed-ability
classrooms and other problems facing today's teachers. Full
references and additional teaching and parental tips are available
at: http://Help4Teachers.com Email her:
Kathie (at) brains.org