Brain Damage From Bipolar
Disorder
By John McMan
McMan's Depression and Bipolar Weekly
If you have a broken leg, you can
tell people you have a fracture in your left tibia. If you have a bad heart you
can let people know you have a weak aortic valve. But
what do you say if you
have a mood disorder? Most of us settle for the explanation that we have
a
chemical imbalance, which is about as satisfactory as your mechanic handing you
a bill with this one item: "Engine Imbalance."
Then there is the matter of collateral damage. We know
depression can
stop the brain it its tracks while mania runs it off the rails, with
corresponding deficits in our ability to think and reason, but we are
led to believe these are only temporary occurrences, right? Maybe not.
If only a mood disorder were just a mood disorder. A lengthy review
article by Carrie Bearden PhD et al of the University of Pennsylvania
published in Bipolar Disorders cites "findings of persistent
neuropsychological deficits" in
long-term bipolar patients, even when
tested in symptom-free states. The relationship between these deficits
and length of illness led the authors to suggest that "episodes of
depression and
mania may exact damage to learning and memory systems."
An article by FC Murphy PhD and BJ Sahakian PhD of Cambridge University
in the British Journal of Psychiatry draws a similar conclusion: "The
balance of evidence ... supports a hypothesis of residual cognitive
impairments."
Father Time appears to be a major factor. Dr Bearden et al cite a study
that found that chronic, multiple-episode patients exhibited more severe
cognitive impairment than younger patients or patients who remit, and
that these impairments were not restricted to their affective episodes.
The same study found 40 percent of the patients were rapid-cyclers.
Another study found that of 25 patients initially hospitalized with
mania with no signs of cognitive impairment, one third showed
significant cognitive impairment five to seven years later.
There is always the possibility that the meds are responsible. One
long-term study found lithium users (one-third who had a university
degree) to be in the low average range on functions of attention and
memory. Nevertheless, the authors believe that while medication may
cause some degree of cognitive slowing, our pills are not the main
culprit.
Bearden et al’s review of what could be wrong with the brain reads like
a neurologist’s laundry list from hell: ventricular enlargements,
cortical atrophy, cerebellar vermal atrophy, white matter hypertensities
(especially in the frontal cortex and basal ganglia structures), greater
left temporal lobe volume, increased amygdala volume, enlarged right
hippocampal volume, hypoplasmia of the medial temporal lobe, and more.
Then there’s the matter of those chemical imbalances, such as glucose
metabolism and phospholipid metabolism.
Say all that in rap time and you have the sound of our brains breaking
down, no longer capable of processing information the way it is supposed
to. It is possible that these studies did not adequately account for the
normal aging process, as Dr Bearden was ready to acknowledge to this
writer, but she also added that it is "likely that there is an
interaction between the disease process and normal aging processes, such
that people affected with bipolar illness are somehow more vulnerable to
the effects of aging."Lest we cause a panic, Dr Bearden wants to remind readers that "while
these brain differences are there, they are subtle. They are certainly
not present in all people with bipolar illness, nor do we really know
what there functional significance may be in any given individual. And
most likely if a radiologist were to take a glance at a brain scan of a
person with bipolar disorder, it would look normal - it's just when you
actually measure things quantitatively that you find differences. I
realize that sometimes these research findings can sound really
horrific, and I don't want to cause anyone undue concern."
Also, it appears that our current bipolar medications actually repair and protect brain
cells, which is one of the better arguments for staying
compliant. Further research in this area may produce new drugs with
enhanced neuroprotective properties.
One day, perhaps, brain doctors will be able to open up the hood and do
a valve job. Researchers at the Salk Institute of Biological Studies
isolated stem cells from the hippocampus of adult rats and modified the
gene to produce glowing proteins, which were cloned and took on the
properties of adult neurons as they matured, including the ability in
some to make synaptic connections with other neurons. Alzheimer's and
Parkinson's come most immediately to mind in the context of this type of
research, but a mood application can't be far beyond that, assuming they
can get the technology to work in humans, which is a very big if. In the
meantime, there is hope, which we may have to suffice for the next
decade or two.
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