2. INTRODUCTION
A chemical imbalance is an irregularity in the cell-
to-cell communication that occurs through various
neurotransmitters and hormones
There is no/very little controversy regarding the
existence of chemical imbalances in severe cases
of mental/psychotic disorders
The controversy lies in cases where the disorder is
determined to be mild
3. TO REITERATE HERE LIES THE CONTROVERSY…
There has yet to be a specific study which states this specific
neurotransmitter causes this specific disorder, however it is
not improbable to identify the potential causal relationship
between chemical imbalances and neural disorders.
Fact: A certain amount of neurotransmitters are required to
achieve optimum nerve conduction, therefore if this
minimal/required amount is lacking, (a chemical imbalance)
the neuron will not function efficiently. -Supported by Medical
Model. From Neurobiology: Molecules, Cells, and
Systems.
4. WHAT DOES THE DSM HAVE TO SAY?
“The pathophysiology of a Major Depressive Episode
may involve a dysregulation of a number of
neurotransmitter systems, including the
serotonin, norepinephrine, dopamine, acetylcholine, and
gamma-aminobuytric systems. There is also evidence of
alteration of several neuropeptides, including
corticotropin-releasing hormone…None of these
changes are present in all individuals in a Major
Depressive Episode, however, nor is any particular
disturbance specific to depression” (DSM-IV-TR)1
5. FOOD FOR THOUGHT
Nature Nurture
Synapses
Mind and Behavior
(the self)
FIGURE 1.22
6. WHY BOTHER WITH THE BRAIN?
Study of the diseased brain has furthered our
understanding of the normal brain.
Historically studying the brain involved certain
injury/death to the patient. Currently there are
various brain scanning techniques used to study
the brain without cutting through a single layer
of tissue.
Scanning methods of measuring include
structural vs. functional aspects of the brain.
7. STRUCTURAL MEASUREMENTS
CAT/CT scan3:
A computerized axial tomography scan is an x-ray
procedure that combines multiple x-ray images to generate
cross-sectional views and, if needed, three-dimensional
images of the internal organs and structures of the body.
MRI4:
A radiology technique designed to image internal
structures of the body using magnetism, radio waves
to produce the images of body structures. In magnetic
resonance imaging (MRI), the scanner is a tube
surrounded by a giant circular magnet.
8. FUNCTIONAL MEASUREMENTS
Positron emission tomography (PET):
A highly specialized imaging technique that uses
short-lived radioactive substances to produce three-
dimensional colored images of those substances
functioning within the body. PET studies metabolic
activity or body function. PET has been used primarily
in cardiology, neurology, and oncology.
fMRI:
The use of magnetic resonance imaging (MRI) to
learn which regions of the brain are active in a
specific function, as in speech. Abbreviated as fMRI.
9. NEUROTRANSMITTERS
Chemicals which relay, amplify, and
modulate signals between neurons and other
cells
Norepinephrine
Dopamine
Seratonin
GABA
10. NOREPINEPHRINE
Neurotransmitter in the catecholamine family
Mediates communication in the sympathetic
nervous system
Stress hormone: released when body senses
stressful conditions; also known as the “fight
or flight” response
Affects attention and responding actions
11. DOPAMINE
Neurotransmitter in the catecholamine family
Neurohormone
Involved in the regulation of:
secretionof some hormones
mood and emotional stability
pain processing
12. SERATONIN
Neurotransmitter
Involved in the regulation of:
Moods (particularly anger and aggression)
Body temperature
Sleep
Appetite
Metabolism
13. GAMMA-AMINOBUTYRIC ACID
Neurotransmitter also known GABA
Regulates neuronal excitability
1950: discovered to be an integral part of
mammalian central nervous system
14. NORMAL VS. AFFECTED BRAIN
5
Frontal Lobe:
-considerable less chemical
activity in the frontal lobes of
affected individuals
-indicates less communication
between cells upon
stimulation
15. ARE WE CAPABLE OF MEASURING
THE STRUCTURE AND FUNCTION
SIMULTANEOUSLY?
Currently: No
This creates another issue:
Currently studies are based on the function of
neurons as clusters or scientifically known as
circuits/neural pathways due to the lack of
multifaceted simultaneous structure and function
testing capabilities.
16. INFLUENCE OF GENETICS
Current studies support that chemical imbalances have a
genetic component
Npas4 gene6
Discovered in 2008 by neuroscientists at the Children’s
Hospital of Boston
Research has been opened to doctors at Harvard and MIT
“Master switch” for synapses
Synapses are the site for signal exchanges between cells/neurons
Represses or activates genes
Linked to the function of more than 200 genes that calm down
over stimulated genes
if over stimulated genes are not controlled, it can lead to
epilepsy, autism, or schizophrenia
With the discovery of this gene, scientists are optimistic in finding a
possible cure for the epilepsy, autism and schizophrenia
17. RESEARCH MAGAZINE7
VOLUME XXIII NUMBER 1 SPRING 2008
“Anatomical causes of epilepsy are often easily identified but are
responsible for less than half of all cases [150,000 Canadians]– leaving
nearly 60 per cent of epilepsy patients with more questions than
answers. The majority of cases are likely the result of a chemical
imbalance in the brain, causing it to function incorrectly, says Dobson.
[Prof. Howard Dobson, Department of Clinical Studies] But what causes
the imbalance is unknown. Currently, researchers think the chemical
imbalance can be caused by any number of factors, including
stress, improper nutrition, illness and depression. They suspect it results
in the nerve fibers – the information highways of the brain – functioning
improperly, leaving the dog or human more susceptible to having a
seizure.”
18. WE KNOW WHAT THE RESEARCH SAYS, LET’S
LOOK AT A PRACTICAL EXAMPLE
But before that…
http://www.blackwellpublishing.com/matthews/actionp.html
19. 8
Although weight, number of drinks, type of drink, and gender may all vary
between two individuals, the fact remains the same, even consuming one
drink affects your BAC7. The same can be attributed to chemical
imbalances.
20. OPTIMALITY AND ROBUSTNESS OF A
BIOPHYSICAL DECISION-MAKING MODEL
UNDER NOREPINEPHRINE MODULATION9
PHILIP ECKHOFF,1 K. F. WONG-LIN,1,2 AND PHILIP HOLMES1,2,3
1PROGRAM IN APPLIED AND COMPUTATIONAL MATHEMATICS, 2CENTER FOR THE STUDY OF
BRAIN, MIND, AND BEHAVIOR, AND 3DEPARTMENT OF MECHANICAL AND AEROSPACE
ENGINEERING, PRINCETON UNIVERSITY, PRINCETON, NEW JERSEY 08544
“NE [Norepinephrine]released by efferent LC fibers (locus
ceruleus- a nucleus in the brainstem) changes cellular
excitability and synaptic efficacy (Berridge and
Waterhouse, 2003) and can alter performance in behavioral
tasks (Berridge and Waterhouse, 2003; Aston-Jones and
Cohen, 2005; Bouret and Sara, 2005). Dysregulation of NE is
also implicated in cognitive disorders (Arnsten, 2007).”
The Journal of Neuroscience, April 1, 2009, 29(13):4301-4311;
doi:10.1523/JNEUROSCI.5024-08.2009
21. TREATMENT
Varies across conditions and severity of
disorder
Identify neurotransmitter involved
Therapy
Lifestyle changes
22. MEDICATION
“Given that many forms of psychopathology has
been associated with various imbalances in
neurotransmitter substances…it is not surprising
that many of the medications used to treat
various disorders have the synapse as their site
of action”
–Neurotransmission and Abnormal Behavior (2.1)
http://www.youtube.com/watch?v=ngi4Hyzp11k
24. SUMMARY
Medical community acknowledges that chemical
imbalances exist and play a role in mental/psychotic
disorders; the field is still growing as doctors and
scientists continue to investigate the extent to which
chemical imbalances are involved
Chemical Imbalances must exist to account for the non-
anatomical causes of neural disorders, although the
effects maybe mild and symptoms may not express
themselves severely, as in anatomical cases. Treating
and correcting chemical imbalances early on would be a
preventive step to avoid the full onset of symptoms.
25. REFERENCES
http://chemicalimbalance.org/?p=21
1.
Joseph LeDoux. 2002, Synaptic Self. How Our brains become who we are.
2.
http://www.medicinenet.com/cat_scan/article.htm
3.
http://www.medterms.com/script/main/art.asp?articlekey=11609
4.
http://www.pharmacology2000.com/Central/psychotics/Antipsy_obj1.htm (PET
5.
Scan)
http://www.blisstree.com/autismvox/a-master-switch-for-synapses-npas4/
6.
(Npas4)
http://www.uoguelph.ca/research/publications/Assets/PDF/ResearchMagazine/
7.
cfi.pdf
http://www.ou.edu/oupd/bac.htm
8.
The Journal of Neuroscience, April 1, 2009, 29(13):4301-4311;
9.
doi:10.1523/JNEUROSCI.5024-08.2009
http://www.blisstree.com/healthbolt/files/2007/03/synapse.jpg
10.
