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Ok, you have
fried your brain, anyway of getting back to normal?
Cognitive Impairment and Recovery From Alcoholism
Brain damage is a common and potentially severe consequence of
long-term, heavy alcohol consumption. Even mild-to-moderate
drinking can adversely affect cognitive functioning (i.e.,
mental activities that involve acquiring, storing, retrieving,
and using information) (1). Persistent cognitive impairment can
contribute to poor job performance in adult alcoholics, and can
interfere with learning and academic achievement in adolescents
with an established pattern of chronic heavy drinking (2). A
small but significant proportion of the heaviest drinkers may
develop devastating, irreversible brain-damage syndromes, such
as Wernicke-Korsakoff syndrome, a disorder in which the patient
is incapable of remembering new information for more than a few
seconds (3).
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It stands to reason that cognitive impairment also may impede
recovery from alcoholism, although evidence has not conclusively
shown this to be the case. For example, Morgenstern and Bates
(4) studied whether deficits in a patient's learning and
planning abilities-core aspects of many treatment
strategies-affected recovery from alcoholism. They found that
impairment was not a significant predictor of poor treatment
response. On the other hand, evidence does support the
possibility that brain damage, whether resulting from or
predating alcohol use, may contribute to the development and
progression of alcoholism (5).
Designing practical strategies to cope with the complex
combination of alcoholism and cognitive impairment requires an
understanding of the nature of cognitive functions and their
interactions with structural and functional brain abnormalities.
This issue of Alcohol Alert describes the nature and
consequences of common alcohol-associated cognitive defects,
explores the extent to which some cognitive abilities recover
with abstinence, and summarizes recent research on the effects
of cognitive deficits on alcoholism treatment outcome.
Cognition and Alcohol
Most alcoholics exhibit mild-to-moderate deficiencies in
intellectual functioning (6), along with diminished brain size
and regional changes in brain-cell activity. The most prevalent
alcohol-associated brain impairments affect visuospatial
abilities and higher cognitive functioning (7). Visuospatial
abilities include perceiving and remembering the relative
locations of objects in 2- and 3-dimensional space. Examples
include driving a car or assembling a piece of furniture based
on instructions contained in a line drawing. Higher cognitive
functioning includes the abstract-thinking capabilities needed
to organize a plan, set it in motion, and change it as needed
(2).
Most alcoholics entering treatment perform as well as
nonalcoholics on tests of overall intelligence. However,
alcoholics perform poorly on neuropsychological tests that
measure specific cognitive abilities (8). For example, an
alcoholic who has remained abstinent after treatment may have no
apparent difficulty filing office documents correctly, a task
that engages multiple brain regions. However, that same person
might be unable to devise a completely different filing system,
a task closely associated with higher cognitive functioning.
How Much Is Too Much?
The link between duration and lifetime quantity of drinking and
the development of cognitive problems is unclear. Some
investigators have proposed that cognitive performance worsens
in direct proportion to the severity and duration of alcoholism
(6,9). Studies suggest that social drinkers who consume more
than 21 drinks per week also fit into this category (6). Other
investigators have suggested that cognitive deficits may be
detectable only in those alcoholics who have been drinking
regularly for 10 years or more (8,10). Long-term,
light-to-moderate social drinkers have been found to fall into
this category as well, showing cognitive deficits equivalent to
those found in detoxified alcoholics (8). Although further
research is needed to determine how a person's pattern of
drinking is related to cognitive impairment, some deficits are
possible even in people who are not heavy drinkers.
Tracking Structural and Functional Brain Abnormalities
Structural and functional brain abnormalities generally are
measured by noninvasive imaging techniques that provide a
picture of the living brain with minimal risk to the individual.
Structural imaging techniques, such as computed tomography and
magnetic resonance imaging, are used to generate computerized
pictures of living tissue. Functional imaging techniques, such
as positron emission tomography and magnetic resonance
spectroscopy, permit scientists to study cell activity by
tracking blood flow and energy metabolism. For more information
about imaging, see Alcohol Alert No. 47, "Imaging and
Alcoholism: A Window on the Brain."
Structural imaging consistently reveals that compared with
nonalcoholics, most alcoholics' brains are smaller and less
dense (11,12). Loss of brain volume is most noticeable in two
areas: the outer layer (i.e., the cortex) of the frontal lobe,
which is considered a major center of higher mental functions
(7,12,13); and the cerebellum, which is responsible largely for
gait and balance as well as certain aspects of learning (14).
Support for these results is provided by functional imaging
studies, which reveal altered brain activity throughout the
cortex and cerebellum of heavy drinkers (15). In addition,
functional imaging often is sufficiently sensitive to detect
these irregularities before they can be observed by structural
imaging techniques, and even before major cognitive problems
themselves become manifest. This suggests that functional
imaging may be particularly useful for detecting the early
stages of cognitive decline (15).
Understanding the Basis of Cognitive Impairment
Accurate measurement of cognitive abilities is challenging, and
relating those abilities to a specific brain irregularity simply
may not be possible with the current technology (16).
Discrepancies among research findings have led scientists to
develop improved cognitive-measuring techniques. Using a battery
of tests, Beatty and colleagues (9) have suggested that
widespread (i.e., diffuse) cognitive impairment could arise from
damage to multiple brain areas, each of which regulates distinct
but related abilities. Likewise, damaging the network of brain
cells that synchronizes the overall activity of those multiple
areas may produce the same cognitive impairments previously
attributed to localized damage (9).
Is Impairment Reversible?
Certain alcohol-related cognitive impairment is reversible with
abstinence (17). Newly detoxified adult alcoholics often exhibit
mild yet significant deficits in some cognitive abilities,
especially problem-solving, short-term memory, and visuospatial
abilities (18). By remaining abstinent, however, the recovering
alcoholic will continue to recover brain function over a period
of several months to 1 year (19)-with improvements in working
memory, visuospatial functioning, and attention-accompanied by
significant increases in brain volume, compared with treated
alcoholics who have subsequently relapsed to drinking (18).
For decades
people have been getting help with addiction through
intervention,
drug
rehab and entering
drug
rehab treatment. Success can be achieved.
Rewiring Brain Networks
Reversibility of alcohol-related cognitive function also may be
the result of a reorganization of key brain-cell networks. Some
researchers have proposed that such reorganization may
contribute to the success of alcoholism treatment. Using
advanced imaging techniques, Pfefferbaum and colleagues (20)
examined the brain activity of cognitively impaired alcoholic
participants during a series of tests designed to assess
cognitive function. They found that although the alcoholic
subjects had abnormal patterns of brain activation, compared
with control subjects, they were able to complete the tasks
equally well, suggesting that the brain systems in alcoholics
can be functionally reorganized so that tasks formerly performed
by alcohol-damaged brain systems are shunted to alternative
brain systems. This finding-that cognitively impaired alcoholic
patients use different brain pathways than unimpaired patients
to achieve equivalent outcome-also was suggested in a study of
patients in 12-step treatment programs (4). Functional brain
reorganization may be particularly advantageous for adolescent
alcohol abusers in treatment, because their developing brains
are still in the process of establishing nerve-cell networks
(21).
Cognitive Function and Alcoholism Treatment
The exact role that cognitive function has in alcoholism
treatment success is unclear. Structural and functional imaging,
as well as more specific cognitive tests, may provide scientists
with the tools needed to reveal subtle relationships between
alcohol-related cognitive impairment and recovery. Meanwhile,
certain conclusions can be drawn from existing research that
help to explain how cognitive function may influence alcoholism
treatment:
Cognitive deficits have been hypothesized to affect the efficacy
of alcoholism treatment, although a clear association has not
been established. One view finds that cognitively impaired
patients may not be able to comprehend the information imparted
during therapy and, thus, may not make full use of the
strategies presented, thereby hampering recovery. Another view
is that cognitive functioning may not directly influence
treatment outcome, but may impact other factors that, in turn,
contribute to treatment success (22). Focusing on those
factors-such as improved nutrition, opportunities for exercise,
careful evaluation of comorbid mental or medical disorders,
and/or treatment strategies aimed at enticing the patient out of
long-standing social isolation-ultimately may be more beneficial
than focusing exclusively on recovery from alcoholism.
Other types of non-alcohol-related brain damage also can produce
symptoms resembling those associated with chronic alcoholism.
Clinicians must be aware that no matter the cause of the
impairment, it may have an impact on the patient's ability to
benefit fully from alcohol-treatment strategies.
Cognitive impairment is usually most severe during the first
weeks of abstinence, perhaps making it difficult for some
alcoholics to benefit from educational and skill-development
sessions, which are important components of many treatment
programs (22,23). For example, one study found that alcoholics
tested soon after entering treatment were unable to recall
treatment-related information presented in a film they had just
been shown (4). As time goes by and cognitive function improves,
however, patients may make better use of information presented
to them in individual and group therapy, educational programs,
and 12-step programs.
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Cognitive Impairment and Recovery From Alcoholism-
A Commentary by NIAAA Director Enoch Gordis, M.D.
The new noninvasive imaging techniques that allow us to "see"
how the brain operates have been a boon to the study of
cognition. Through this medium, we now know that the brain is
capable of "rewiring" itself. In doing so, the brain can regain
some of the cognitive abilities previously diminished as a
result of damage from alcohol or other diseases. The brain's
remarkable ability to recover is important for at least two
reasons. First, alcohol use over a period of time, even at low
levels of drinking, can produce varying degrees of cognitive
damage, a problem that is of particular concern because alcohol
use is so widespread. Thus, the brain's self-repairing ability
may help defer or reduce alcohol-induced cognitive problems
among a large portion of the population. Second, the brain's
ability to rewire itself may have implications in terms of
adolescent drinking. Recent evidence suggests that the
adolescent brain, which is still forming important cellular
connections, is more vulnerable than the adult brain to
alcohol-induced damage. This is particularly troubling, given
the problems associated with chronic binge drinking, which is
all too common among young people. The brain's ability to rewire
important neurological systems might help mitigate a lifetime of
cognitive difficulties resulting from chronic drinking during
adolescence, but we do not yet know if this is true. Future
research will help clarify this and other important questions
about alcohol's effect on cognition.
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