Recent alcohol research

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There was an interesting recent news story from Reuters. Researchers at the University of Missouri-Columbia found that, “Young adults who binge drink frequently are more likely to show disadvantageous decision-making patterns than their peers who don’t drink as heavily” (from the news article). You can’t assume that just because drinking and poor decision making are correlated that the drinking causes the poor decisions (because people who are poorer at decision making in general may drink more) but as I like to say, “Correlation does not imply causation but neither does does it deny causation.”

On the other hand, there is some evidence that drinking alcohol might slow down the progression and/or onset of dementia (e.g., Alzheimer’s Disease): Alcohol and dementia article. Again, the study is correlational so firm causations should not be inferred.

These two articles demonstrate that there is still a lot of  uncertainty about the long-term effects of alcohol consumption.

Anosognosia and Dementia

Anosognosia is a word that means unawareness of functional deficit. It is a common condition in people with Alzheimer’s Disease (AD) – they are not fully aware of their deficits. We can’t state that people with AD never have awareness of their deficits because there is a fair amount of evidence that in the earlier stages of AD there is at least some awareness of memory problems and slowed cognition. The relative anosognosia in AD patients can be contrasted with Parkinson’s patients who are all too aware of their deficits. Theirs is mainly a motoric disorder, which is brought about by neuronal death in the substantia nigra, an area of the brain that produces dopamine (a neurotransmitter). The resting tremors and slowed movements can been extremely frustrating to people with Parkinson’s disease because they are completely aware of their problems.

On Alzheimer’s Disease and other dementias

There are two general classes of dementias: cortical and subcortical. A cortical dementia is one like Alzheimer’s Disease (AD) where the outer layer (the “bark”) of the brain is first affected. AD typically affects the ventromedial frontal and dorsomedial temporal lobes first. The medial portions of the temporal lobes (e.g., hippocampus and parahippocampal gyrus) are heavily involved in memory processes. So typically with AD we first see atrophy (or volume loss) in those regions; the gray matter (bodies of neurons) die off and the brain shrinks. We are still not entirely sure what causes AD – we know genetics plays a part as do environmental factors such as exercise, nutrition, and education but we don’t know the specific pathology of the disease. AD also is related to swelling to some degree; so an adult who is approaching old age can likely reduce the chances of getting AD simply by taking a “baby aspirin” daily. At the very least it will likely delay the onset and slow down the progression of the disease.

There are also subcortical dementias. These can occur as a result of stroke, Huntington’s disease, or Parkinson’s disease. These types of dementias can occur and worsen rapidly (in the case of strokes) or can be fairly mild initially (as in Parkinson’s-type dementias). Subcortical dementias will over time and in the latest stages of the disease become indistinguishable from AD. Another type of subcortical dementia is Dementia with Lewy Bodies (DLB, or Lewy-body dementia). This is a disease that appears to combine aspects of Parkinson’s, Alzheimer’s, and schizophrenia. People with DLB often have vivid visual hallucinations and other psychoses. It is a terrible disease for the person with it as well as caretakers and family.