Parts of the brain affected by alcoholism

Thinking 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 thinking functioning (i.e., mental activities that involve acquiring, storing, retrieving, and using information).

Persistent thinking 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.

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 .

It stands to reason that thinking impairment also may impede recovery from alcoholism, although evidence has not conclusively shown this to be the case.  For example, one study looked at 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.

Thinking and Alcohol

Most alcoholics exhibit mild-to-moderate deficiencies in intellectual functioning, along with diminished brain size and regional changes in brain-cell activity. The most prevalent alcohol-associated brain impairments affect visuospatial abilities and higher thinking functioning. 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 thinking functioning includes the abstract-thinking capabilities needed to organize a plan, set it in motion, and change it as needed .

Most alcoholics entering treatment perform as well as non-alcoholics on tests of overall intelligence. However, alcoholics perform poorly on neuropsychological tests that measure specific thinking abilities. 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 thinking functioning.

Tracking Structural and Functional Brain Abnormalities

Structural and functional brain abnormalities generally are measured by non-invasive 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.

Structural imaging consistently reveals that compared with non-alcoholics, most alcoholics’ brains are smaller and less dense. 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; and the cerebellum, which is responsible largely for gait and balance as well as certain aspects of learning.

Support for these results is provided by functional imaging studies, which reveal altered brain activity throughout the cortex and cerebellum of heavy drinkers.

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 thinking problems themselves become manifest. This suggests that functional imaging may be particularly useful for detecting the early stages of thinking decline.

Understanding the Basis of Thinking Impairment

Accurate measurement of thinking abilities is challenging, and relating those abilities to a specific brain irregularity simply may not be possible with the current technology.

Discrepancies among research findings have led scientists to develop improved thinking-measuring techniques. Using a battery of tests, Beatty and colleagues have suggested that widespread (i.e., diffuse) thinking 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 thinking impairments previously attributed to localized damage.

Is Impairment Reversible?

Certain alcohol-related thinking impairment is reversible with abstinence.

Newly detoxified adult alcoholics often exhibit mild yet significant deficits in some thinking abilities, especially problem-solving, short-term memory, and visuospatial abilities.

By remaining abstinent, however, the recovering alcoholic will continue to recover brain function over a period of several months to 1 year -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 .

Rewiring Brain Networks

Reversibility of alcohol-related thinking 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 examined the brain activity of thinking impaired alcoholic participants during a series of tests designed to assess thinking 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 thinking 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.

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 .

Thinking Function and Alcoholism Treatment

The exact role that thinking function has in alcoholism treatment success is unclear. Structural and functional imaging, as well as more specific thinking tests, may provide scientists with the tools needed to reveal subtle relationships between alcohol-related thinking impairment and recovery.

Meanwhile, certain conclusions can be drawn from existing research that help to explain how thinking function may influence alcoholism treatment:

Thinking deficits have been hypothesized to affect the efficacy of alcoholism treatment, although a clear association has not been established

  • .One view finds that thinking 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 thinking functioning may not directly influence treatment outcome, but may impact other factors that, in turn, contribute to treatment success.
  • 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.

Related Reading:

The Turmoil of Someone Else's Drinking
Seven Weeks to Sobriety: The Proven Program to Fight Alcoholism through Nutrition
Alcoholics Anonymous: Reproduction of the First Printing of the First Edition
Relapse Toolkit