Alcohol's damage to the brain

While moderate drinking seems to have a protective effect against age-related cognitive decline and dementia, cognitive impairment produced by excess alcohol is only too evident. Here are a few less obvious cognitive effects:

Simulated laparoscopic surgery was impaired in both novices and experts on the day following an evening during which excessive alcohol was consumed, although experts were less impaired than novices. Performance had returned to baseline levels by 4:00 p.m.

When people drank before viewing a video of serious road traffic accidents, those given a smaller amount of alcohol experienced more flashbacks during the next week than those given a larger amount of alcohol, and those given no alcohol. Those who had large amounts of alcohol had poorer memories of the event. It’s suggested that alcohol impairs contextual memory first.

Another study found that recognition of different-race faces was unaffected by alcohol, but recognition of own-race faces was — meaning recognition of same-race faces was at about the same level of accuracy as different-race faces.

Cognitive impairment produced by excess alcohol is of course only too evident. Here are a few less obvious cognitive effects:

Simulated laparoscopic surgery was impaired in both novices and experts on the day following an evening during which excessive alcohol was consumed, although experts were less impaired than novices. Performance had returned to baseline levels by 4:00 p.m.

When people drank before viewing a video of serious road traffic accidents, those given a smaller amount of alcohol experienced more flashbacks during the next week than those given a larger amount of alcohol, and those given no alcohol. Those who had large amounts of alcohol had poorer memories of the event. It’s suggested that alcohol impairs contextual memory first.

Another study found that recognition of different-race faces was unaffected by alcohol, but recognition of own-race faces was — meaning recognition of same-race faces was at about the same level of accuracy as different-race faces.

Heavy drinking

Heavy drinking can be chronic, or occasional. Both have their price.

A rat study suggests that it doesn’t take all that long before heavy drinking produces long-lasting cognitive deficits. Rats drinking for eight weeks (but not four) developed deficits that lasted at least 12 weeks after drinking stopped — “equivalent to a human that drank six to eight beers or one bottle of wine a day every day for six years experiencing learning and memory deficits up to nine years after they stopped drinking alcohol."

Brain scans of heavy social drinkers have revealed damage to white matter that was associated with lower executive and working memory functions. This is consistent with a self-report study that found that heavy users of alcohol were more likely to miss appointments, forget birthdays and pay bills on time, and to forget whether they had done something or where they had put something.

One study suggests that heavy drinking is particularly a problem for those infected with HIV. The mediotemporal lobe is affected early in both these conditions, so it is not surprising that those positive for HIV with a history of chronic heavy drinking were found to have trouble encoding new information for long-term memory.

Smoking and alcohol

Smoking has a particularly negative effect in conjunction with alcohol (and unfortunately they are often found in tandem). While moderate drinking can in some circumstances have positive effects on the brain, this is probably not the case for those who smoke. Moreover, smoking makes it much harder for the brain to recover from the effects of alcohol abuse, the damage done to the brain by heavy alcohol consumption is likely to be much worse if the individual is a smoker.

Alcoholism

One of the characteristics of alcoholics is that they don’t recognize the extent of their problem. So perhaps it’s no surprise that a study found that alcoholics were relatively unaware of their memory deficits and believed that their memory was much better than it was. Moreover, the greater their deficits, the less they were aware of them!

Years of heavy alcohol consumption impair executive functions, including judgment, problem solving, decision making, planning, and social conduct.

Imaging studies indicate that the brains of alcoholics develop compensatory mechanisms to maintain cognitive skills despite alcohol's damages. It seems likely that this wider activity comes at the expense of other tasks, thus reducing their ability to multitask.

Excessive chronic drinking is also associated with deficits in comprehending emotional information, such as recognizing different facial expressions, and visuospatial deficits, characterized by difficulties completing tasks such as putting pieces of a puzzle together or map reading. While long-term abstinence can recover most of the cognitive function lost, spatial processing abilities seem much harder to recover.

In line with these problems of executive function, episodic and spatial memory, the prefrontal cortex and the hippocampus are especially vulnerable to the effects of chronic alcoholism.

Alcoholics have also been found to have an impaired cortisol response to stress, and this is associated with lower scores on measures of problem-solving ability and memory. Another exacerbating factor may come from poorer sleep — recovering alcoholics have been found to have significantly poorer sleep quality.

There is some evidence that women are more vulnerable to the effects of binge drinking and chronic heavy drinking.

Alcohol and the adolescent brain

Binge drinking is particularly evident among young people. Several studies point to effects on executive functions, including attention and working memory. This has consequences for planning and decision-making, as well as memory tasks.

Memory impairment following too much alcohol is particularly common among adolescent drinkers, possibly because of disruption in the hippocampus, which is still developing during adolescence.

Other physiological consequences of teenage binge drinking may be damaged white matter connectivity, and reduced activity of many neurotransmitter genes. There is some indication that some of these effects may persist into adulthood.

Prenatal exposure

Studies suggest that there is no safe dose, nor safe time to drink, for pregnant women, although the timing does affect the nature of the damage. It seems that alcohol is especially damaging for the development of the dopamine system.

Children prenatally exposed to alcohol are not consistently impaired however. A monkey study suggests why — it seems a gene variant makes the carrier more susceptible to the effects of fetal alcohol exposure. The gene has previously been implicated in increased depression risk.

Other research has suggested that children whose mothers are older than 30 years, those whose mothers have alcohol dependence, those whose parents provide a less stimulating environment, and those whose mothers reported drinking during the time of conception, are at greater risk from prenatal alcohol exposure.

It’s also the case that cognitive deficits are not always evident. One study found that children prenatally exposed to moderate-to-heavy levels of alcohol were perfectly competent at simple tasks, but failed when asked to multi-task. Such working memory deficits may partly be a result of slower processing speed.

Hope comes from a finding that two factors can considerably mitigate the negative effects of prenatal alcohol exposure: being diagnosed early in life and being raised in a stable and nurturing environment.

Children with fetal alcohol spectrum disorder are particularly impaired in mathematical ability, possibly due to specific deficits in memory for numbers and sequences.

Distinguishing Fetal Alcohol Spectrum Disorder from other developmental disorders may have got easier, with a simple test that measures eye movement.

Chronic use of alcohol and marijuana during youth has been associated with poorer neural and cognitive function, which appears to continue into adulthood. A new study looking specifically at white-matter changes provides more support for the idea that adolescent brains may be at particular risk from the damage that substance abuse can bring.

The brain-imaging study compared 41 adolescents (aged 16-20) with extensive marijuana- and alcohol-use histories by mid-adolescence with 51 adolescents with no such history. The study found that substance users showed poorer white matter integrity in seven tracts (right and left superior longitudinal fasciculus, right posterior thalamic radiations, right prefrontal thalamic fibers, right superior temporal gyrus white matter, right inferior longitudinal fasciculus, left posterior corona radiata).

Two brain scans were taken, at baseline and at 18 months. Substance use interviews were given every six months.

More alcohol use during the interval was associated with worse integrity in both the right and left superior longitudinal fasciculi, above and beyond baseline values in these bundles. Marijuana use didn’t predict change over time. Those who had a history of more risk-taking behaviors showed poorer integrity of the right prefrontal thalamic fibers.

The findings add to previous research showing white matter problems in youth with substance-use histories. The study points to alcohol use during adolescence being particularly problematic. It also suggests that youth who engage in risk-taking behaviors may tend to have poorly developed fronto-thalamic tracts.

All of this is particularly worrying because it is thought that maturation of the brain during adolescence is the foundation for self-control, suggesting that substance abuse during this period may have long-lasting effects on the individual’s ability to plan, organize, and self-regulate.

It’s always difficult in human studies to disentangle the effects of lifestyle factors. Alcohol is a case in point, and in particular the vexed question of whether any alcohol is safe during pregnancy. A new study, however, has avoided the complication of co-occurring lifestyle and environment factors by looking directly at genetic variants.

This study, believed to be the first substantial one of its kind, used genetic variation to investigate the effects of moderate (<6 units of alcohol per week) drinking during pregnancy among a large group of women and their children. Since the individual variations that people have in their DNA are not connected to lifestyle and social factors, the approach removes that potential complication.

The study, involving 4,167 children, found that four genetic variants in alcohol-metabolizing genes were strongly related to lower IQ at age eight. But this effect was only seen among the children of women who were moderate drinkers (heavy drinkers were not included in the study), pointing to the effect requiring exposure to alcohol in the womb.

Ten SNPs from four genes previously implicated in alcohol metabolism, intake, or dependency, were analyzed. Four SNPs (particular variants) were related to children’s scores on the cognitive test (WISC), of which three are rare and one quite common. There was an additive effect, with carriers of multiple ‘bad’ alleles being more affected.

There was some evidence that only drinking one or two drinks a week was not harmful to the fetus, but because the numbers of women were relatively small, and individual variability was high, this can’t be assessed with any great certainty.

The critical factor appears to be metabolism of alcohol, with mothers who are ‘fast' metabolizers being safer for their fetus than mothers who metabolize alcohol more slowly.

Mothers' alcohol intake was based on questionnaires completed when they were 18 weeks and 32 weeks pregnant. ‘Moderate’ was defined as between one and six drinks a week. All participants were of white-European origin.

Binge drinking occurs most frequently among young people, and there has been concern that consequences will be especially severe if the brain is still developing, as it is in adolescence. Because of the fact that it is only some parts of the brain — most crucially the prefrontal cortex and the hippocampus — that are still developing, it makes sense that only some functions will be affected.

I recently reported on a finding that binge drinking university students, performed more poorly on tests of verbal memory, but not on a test of visual memory. A new study looks at another function: spatial working memory. This task involves the hippocampus, and animal research has indicated that this region may be especially vulnerable to binge drinking. Spatial working memory is involved in such activities as driving, figural reasoning, sports, and navigation.

The study involved 95 adolescents (aged 16-19) from San Diego-area public schools: 40 binge drinking (27 males, 13 females) and 55 control (31 males, 24 females). Brain scans while performing a spatial working memory task revealed that there were significant gender differences in brain activation patterns for those who engaged in binge drinking. Specifically, in eight regions spanning the frontal cortex, anterior cingulate, temporal cortex, and cerebellum, female binge drinkers showed less activation than female controls, while male bingers exhibited greater activation than male controls. For female binge drinkers, less activation was associated with poorer sustained attention and working memory performances, while for male binge drinkers, greater activation was linked to better spatial performance.

The differences between male binge drinkers and controls were smaller than that seen in the female groups, suggesting that female teens may be particularly vulnerable. This is not the first study to find a gender difference in the brains’ response to excess alcohol. In this case it may have to do, at least partly, with differences in maturity — female brains mature earlier than males’.

Following animal research indicating that binge drinking damages the hippocampus, and other research showing that this learning and memory center is still developing during adolescence, a new study has investigated the effects of binge drinking on learning in university students. The study, involving 122 Spanish university students (aged 18-20), of whom half engaged in binge drinking, found a clear association between binge drinking and a lower ability to learn new verbal information.

Specifically, binge drinkers were more affected by interference in the Rey Auditory Verbal Learning Test, and remembered fewer words; they also performed worse on the Weschler Memory Scale-3rd ed. (WMS-III) Logical Memory subtest, both on immediate and delayed recall. However, there were no differences between the two groups on the WMS-III Family Pictures subtest (measuring visual declarative memory).

These results persisted even after controlling for other possible confounding variables such as intellectual levels, history of neurological or psychopathological disorders, other drug use, or family history of alcoholism.

The genders were evenly represented in both groups. Interestingly, and in contradiction of some other research, women were not found to be more vulnerable to the neurotoxic effects of binge drinking.

Laparoscopic surgery makes intense demands on cognitive, perceptual and visuospatial abilities, rendering it particularly vulnerable to the effects of alcohol (and also making it a sensitive indicator). In a real-world type experiment, students and experts participated in a study looking at the effects of previous-night’s carousing on next-day’s performance on the Minimally Invasive Surgical Trainer Virtual Reality (for which all participants received training, providing baseline scores).

The first experiment involved 16 male final-year science students, of whom 8 were asked to consume alcohol freely at a group dinner, while the other 8 went to a dinner at which no alcohol was served. The second experiment involved eight laparoscopic experts, all of whom were asked to consume alcohol freely at their group dinner. Participants were tested on the simulator the next day at 9:00 a.m., 1:00 p.m. and 4:00 p.m.

Among the students, those who had consumed excessive alcohol performed considerably worse in terms of time, errors and economy of diathermy (ability to perform technique designed to produce local application of heat), and showed considerable performance variability. Their performance in terms of errors and diathermy was significantly impaired compared to that of the control group. Differences in the time it took participants to perform the tasks were only significant at 9:00 a.m.

Experts were (thankfully!) less impaired by their night out. Nevertheless, they made more errors than they had at baseline, and the difference at 1:00 p.m. was statistically significant. They were also significantly slower during the 1:00 p.m. tests. Performance had returned to baseline levels by 4:00 p.m.

Binge drinking is, unfortunately, most common among adolescents (12-20 years). But this is a time when brains are still developing. Does this make them more vulnerable to the detrimental effects of excessive alcohol?

A study involving adolescent mice has revealed that not only did an alcoholic binge reduce the activity of many neurotransmitter genes, but that gene expression in adulthood was even more seriously reduced. Although this deficit didn’t translate into problems with spatial learning, adult mice that had been exposed to excess alcohol in adolescence were significantly worse on a reversal learning task. Moreover, certain brain regions (the olfactory bulb and basal forebrain) were smaller.

In humans, it is thought that these impairments might translate into greater difficulty in adapting to changed situations, in evaluating consequences and controlling impulses.

Similarly, another recent study involving teenagers (15-21) has found that activity in the prefrontal cortex varied according to how heavily they smoked, with those who smoked most heavily having the least activity.

The 25 smokers and 25 non-smokers were tested on a Stop-Signal Task, which tests a person’s ability to inhibit an action. Despite the differences in activity level, smokers and non-smokers performed similarly on the task, suggesting that other brain areas are in some way compensating for the impaired prefrontal cortex. Nevertheless, reduced activity in the prefrontal cortex, which is still developing in adolescence, does suggest long-term consequences for decision-making and cognitive control.

A study involving 48 adolescents, of whom 19 had been diagnosed with substance abuse/dependence, and 14 had a family history of substance abuse but no history of personal use, has found that greater alcohol use was associated with a significant decrease in attention and executive function (which is involved in planning and decision-making), while greater marijuana use was associated with poorer memory. Adolescents in the substance abuse group had lower scores in attention, memory, and processing speed, compared to the other groups, while those with a family history of abuse (but no personal history) had poorer visuospatial ability.

Data from 217 children from Inuit communities in Arctic Quebec (average age 11), of whom some had mothers that reported binge drinking during pregnancy, has revealed that the alcohol-exposed group, while similar to the control in accuracy and reaction time, showed a significant differences in their brains’ electrical activity while doing those tasks (a Go/No-go response inhibition task and a continuous recognition memory task). The differences suggest that fetal alcohol exposure is associated with reduced efficiency in the initial extracting of the meaning of a stimulus, reduced allocation of attention to the task, and poorer conscious recognition memory processing.

Metamemory (understanding your own memory capabilities) is important for learning. Now a study involving 28 alcoholics has found that, compared to controls, they not only performed more poorly on a test of episodic memory, but they were less accurate in their assessments of how good their memory was. The episodic memory task involved learning 20 pairs of items, followed by a recall and a recognition test 20 minutes later. Before the recognition test, participants rated their ability to recognize each nonrecalled word among 4 items. The alcoholics were relatively unaware of their memory deficits and believed that their memory was much better than it was. On a questionnaire of their general memory capacities, they also tended to report themselves as much more capable than they were. Their over-estimation was related to their low performance on tests of executive function.

The finding has implications for any recovery program, since alcoholics will tend to believe that they have mastered any learning long before they have.

An imaging study has revealed that children (aged 5-15) whose mothers abused methamphetamine and alcohol during pregnancy had structural abnormalities in the brain that were more severe than those seen in children whose mothers abused alcohol alone. In particular, the striatal region was significantly smaller, and within the group, size of the caudate correlated negatively with IQ. Limbic structures, in particularly the cingulate cortex and the right inferior frontal gyrus, were significantly bigger. The striatal and limbic structures are also known to be particularly affected in adult methamphetamine abusers.

Older news items (pre-2010) brought over from the old website

Alcoholism's effect on sleep persists

A study involving 42 long-term alcoholics who had not had a drink for up to 719 days (mean age 49 years, 27 men) has found that, compared to controls, alcoholics had significantly poorer sleep quality, measured by a significantly lower percentage of slow wave sleep and significantly more stage 1 non-rapid eye movement (NREM) sleep. Moreover, estimated lifetime alcohol consumption was significantly related to the scores on the Pittsburgh Sleep Quality Index, with higher lifetime consumption predicting less sleep satisfaction. The reduction in slow wave activity was specific to NREM sleep. This could act as an exacerbating factor in alcoholics' cognitive decline.

[792] Colrain, I. M., Turlington S., & Baker F. C. (2009).  Impact of alcoholism on sleep architecture and EEG power spectra in men and women. Sleep. 32(10), 1341 - 1352.

http://www.eurekalert.org/pub_releases/2009-10/aaos-aeo092309.php

Alcoholics show abnormal brain activity when processing facial expressions

Excessive chronic drinking is known to be associated with deficits in comprehending emotional information, such as recognizing different facial expressions. Now an imaging study of abstinent long-term alcoholics has found that they show decreased and abnormal activity in the amygdala and hippocampus when looking at facial expressions. They also show increased activity in the lateral prefrontal cortex, perhaps in an attempt to compensate for the failure of the limbic areas. The finding is consistent with other studies showing alcoholics invoking additional and sometimes higher-order brain systems to accomplish a relatively simple task at normal levels. The study compared 15 abstinent long-term alcoholics and 15 healthy, nonalcoholic controls, matched on socioeconomic backgrounds, age, education, and IQ.

[1044] Marinkovic, K., Oscar-Berman M., Urban T., O'Reilly C. E., Howard J. A., Sawyer K., et al. (2009).  Alcoholism and dampened temporal limbic activation to emotional faces. Alcoholism, Clinical and Experimental Research. 33(11), 1880 - 1892.

http://www.eurekalert.org/pub_releases/2009-08/ace-edc080509.php
http://www.eurekalert.org/pub_releases/2009-08/bumc-rfa081109.php

Binge drinking affects attention and working memory in young university students

A Spanish study of 95 first-year university students, 42 of them binge drinkers, has found that those who engaged in binge drinking required greater attentional processing during a visual working memory task in order to carry it out correctly. They also had difficulties differentiating between relevant and irrelevant stimuli. Binge drinkers are defined as males who drink five or more standard alcohol drinks, and females who drink four or more, on one occasion and within a two-hour interval. Some 40% of university students in the U.S. are considered binge drinkers.

[231] Crego A, Holguín SR, Parada M, Mota N, Corral M, Cadaveira F. Binge drinking affects attentional and visual working memory processing in young university students. Alcoholism, Clinical and Experimental Research [Internet]. 2009 ;33(11):1870 - 1879. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19673739

http://www.eurekalert.org/pub_releases/2009-08/ace-bda080509.php

HIV infection and chronic drinking together impair encoding of new experiences

A study involving 40 individuals with HIV, 38 with chronic alcoholism, 47 with both HIV and chronic alcoholism, and 39 controls, has found that although those with only one of these disorders mostly performed at levels comparable to controls on episodic and working memory tasks, those who were both positive for HIV and had a history of chronic heavy drinking were impaired on tests of immediate episodic memory (but not working memory) — meaning that they have trouble encoding new information for long-term memory. The finding is consistent with the fact that the mediotemporal lobe is affected early by both these conditions. Heavy drinking is very common among those infected with HIV.

[440] Fama R, Rosenbloom MJ, Nichols NB, Pfefferbaum A, Sullivan EV. Working and episodic memory in HIV infection, alcoholism, and their comorbidity: baseline and 1-year follow-up examinations. Alcoholism, Clinical and Experimental Research [Internet]. 2009 ;33(10):1815 - 1824. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19656122

http://www.eurekalert.org/pub_releases/2009-07/ace-hia072009.php

Adolescent binge drinking may compromise white matter

An imaging study of 28 teens, of whom half had a history of binge drinking (but did not meet the criteria for alcohol abuse), has found that those who had engaged in binge drinking episodes had lower coherence of white matter fibers in 18 different areas across the brain. The findings add to a growing literature indicating that adolescent alcohol involvement is associated with specific brain characteristics. White matter integrity is essential to the efficient relay of information in the brain.

[1426] McQueeny T, Schweinsburg BC, Schweinsburg AD, Jacobus J, Bava S, Frank LR, Tapert SF. Altered white matter integrity in adolescent binge drinkers. Alcoholism, Clinical and Experimental Research [Internet]. 2009 ;33(7):1278 - 1285. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19389185

http://www.physorg.com/news159646086.html
http://www.eurekalert.org/pub_releases/2009-04/ace-abd041509.php

Alcoholics’ brains maintain language skills at a cost

Despite the damage done by alcoholism to the frontal lobes and cerebellum, areas involved in language processing, alcoholics' language skills appear to be relatively spared from alcohol's damaging effects. A new study of 12 alcoholic males and 12 healthy controls suggests that alcoholics develop compensatory mechanisms to maintain their language skills despite alcohol's damages. The comparable performance on an auditory language task between the two groups was underlain by different neural activity (specifically, the alcoholic group showed greater activity in the left middle frontal gyrus, the right superior frontal gyrus, and the cerebellar vermis). It seems likely that this wider activity comes at the expense of other tasks, thus reducing their ability to multitask.

[926] Chanraud-Guillermo, S., Andoh J., Martelli C., Artiges E., Pallier C., Aubin H. - J., et al. (2009).  Imaging of language-related brain regions in detoxified alcoholics. Alcoholism, Clinical and Experimental Research. 33(6), 977 - 984.

http://www.eurekalert.org/pub_releases/2009-03/ace-tbm031209.php

Drinking alcohol associated with smaller brain volume

It is estimated that brain volume decreases by 1.9% per decade, accompanied by an increase in white matter lesions. Because moderate alcohol consumption has been associated with a lower risk of cardiovascular disease, it’s been thought that small amounts of alcohol might also reduce age-related declines in brain volume, although it’s known that large amounts of alcohol will reduce brain volume. However, a large, long-running study, has now found that, even at low levels of alcohol consumption, brain volume was negatively affected. Moreover, although men were more likely to be heavier drinkers, the association between drinking and brain volume was stronger in women.

[1191] Paul CA, Au R, Fredman L, Massaro JM, Seshadri S, DeCarli C, Wolf PA. Association of Alcohol Consumption With Brain Volume in the Framingham Study. Arch Neurol [Internet]. 2008 ;65(10):1363 - 1367. Available from: http://archneur.ama-assn.org/cgi/content/abstract/65/10/1363

http://www.eurekalert.org/pub_releases/2008-10/jaaj-daa100908.php

Heavy, chronic drinking can cause significant hippocampal tissue loss

An imaging study of 8 heavy-drinking alcoholics and 8 age and ethnicity matched non-alcoholics (all male) found that total hippocampus volume was significantly reduced among the alcoholics.

[677] Beresford, T. P., Arciniegas D. B., Alfers J., Clapp L., Martin B., Du Y., et al. (2006).  Hippocampus Volume Loss Due to Chronic Heavy Drinking. Alcoholism: Clinical and Experimental Research. 30(11), 1866 - 1870.

http://www.eurekalert.org/pub_releases/2006-10/ace-hcd101606.php

Most of the cognitive deficits associated with alcoholism recoverable

Results of a study involving middle-aged alcoholics who have been sober for six months to 13 years, suggest that long-term abstinent alcoholics can recover most of their neurocognitive deficits. However, deficits in spatial-processing abilities continued. Visuospatial processes are important for many daily activities, including driving, reading a map, assembling things, and performing tasks that require spatial orientation. The study doesn’t however know how much damage had been done when the alcoholics ceased drinking; further studies are exploring the recovery of older abstinent alcoholics who ceased drinking at different ages.

[856] Fein, G., Torres J., Price L. J., & Sclafani V. D. (2006).  Cognitive Performance in Long-Term Abstinent Alcoholic Individuals. Alcoholism: Clinical and Experimental Research. 30(9), 1538 - 1544.

http://www.eurekalert.org/pub_releases/2006-08/ace-lam082106.php

Brain atrophy occurs faster in women alcoholics

A study of 34 male and 42 female alcoholics has found that, although the women had been alcoholics for just 5.5 years on average, compared to the average 10.4 years for the men, the women had lost as much proportionate brain volume as the men. The findings are consistent with other studies suggesting that women suffer from the effects of alcohol abuse faster.

[1258] Mann, K., Ackermann K., Croissant B., Mundle G., Nakovics H., & Diehl A. (2005).  Neuroimaging of Gender Differences in Alcohol Dependence: Are Women More Vulnerable?. Alcoholism: Clinical and Experimental Research. 29(5), 896 - 901.

http://www.nature.com/news/2005/050509/full/050509-15.html

Drinking for just eight weeks impairs learning and memory in mice

It’s well established that chronic alcohol consumption can produce deficits in learning and memory. A new rodent study, however, is the first to show that continuous drinking for as little as eight weeks can produce deficits in learning and memory that last at least 12 weeks after drinking stopped — “equivalent to a human that drank six to eight beers or one bottle of wine a day every day for six years experiencing learning and memory deficits up to nine years after they stopped drinking alcohol." These deficits were global — that is, they affected long-term memory for every type of task tested. Short-term memory was not affected. Rats who drank for only four weeks did not experience the same effects.

[522] Farr SA, Scherrer JF, Banks WA, Flood JF, Morley JE. Chronic Ethanol Consumption Impairs Learning and Memory After Cessation of Ethanol. Alcoholism: Clinical and Experimental Research [Internet]. 2005 ;29(6):971 - 982. Available from: http://dx.doi.org/10.1097/01.ALC.0000171038.03371.56

http://www.eurekalert.org/pub_releases/2005-06/ace-dfj060605.php

Cognitive effects of binge drinking worse for women

A new study looked at the cognitive effects of binge drinking, which apparently is on the rise in several countries, including Britain and the US. The study involved 100 healthy moderate-to-heavy social drinkers aged between 18 and 30. There were equal numbers of males and females. The study found that female binge drinkers performed worse on the working-memory and vigilance tasks than did the female non-binge drinkers.

[1311] Townshend JM, Duka T. Binge Drinking, Cognitive Performance and Mood in a Population of Young Social Drinkers. Alcoholism: Clinical and Experimental Research [Internet]. 2005 ;29(3):317 - 325. Available from: http://dx.doi.org/10.1097/01.ALC.0000156453.05028.F5

http://www.eurekalert.org/pub_releases/2005-03/ace-bdc030705.php

Alcohol's damaging effects on adolescent brain function

A number of speakers at Symposium speakers at the June 2004 Research Society on Alcoholism meeting in Vancouver, reported on research concerning the vulnerability of the adolescent brain to the damaging effects of alcohol. Some of the findings presented were:

  • The adolescent brain is more vulnerable than the adult brain to disruption from activities such as binge drinking. Adolescent rats that were exposed to binge drinking appear to have permanent damage in their adult brains.
  • Subtle but important brain changes occur among adolescents with Alcohol Use Disorder, resulting in a decreased ability in problem solving, verbal and non-verbal retrieval, visuospatial skills, and working memory.
  • The association between antisocial behavior during adolescence and alcoholism may be explained by abnormalities in the frontal limbic system, which appears to cause "blunted emotional reactivity".
  • Alcohol-induced memory impairments, such as "blackouts", are particularly common among young drinkers and may be at least in part due to disrupted neural plasticity in the hippocampus, which is centrally involved in the formation of autobiographical memories.

[1238] Monti PM, Miranda, Jr R, Nixon K, Sher KJ, Swartzwelder SH, Tapert SF, White A, Crews FT. Adolescence: Booze, Brains, and Behavior. Alcoholism: Clinical and Experimental Research [Internet]. 2005 ;29(2):207 - 220. Available from: http://dx.doi.org/10.1097/01.ALC.0000153551.11000.F3

http://www.eurekalert.org/pub_releases/2005-02/ace-ade020705.php

Alcoholics can have deficits in visuoperception and frontal executive function despite sobriety

Detoxified alcoholics often have visuospatial and visuoperceptual deficits, characterized by difficulties completing tasks such as putting pieces of a puzzle together or map reading. A new study has found that, even with prolonged sobriety, alcoholics show deficits in visuoperception and frontal executive functioning of the brain. Furthermore, alcoholics utilize a more complex higher-order cognitive system (frontal executive functions) to perform the same tasks as individuals without a history of alcoholism. The potential problem with this is that if that same system is needed for a competing task, alcoholics may be at a disadvantage because that system would otherwise be engaged. The study involved 51 recently detoxified nonamnesic alcoholic men (ages 29 to 66 years) compared with 63 "normal," control men (ages 21 to 70 years).

Fama, R., Pfefferbaum, A. & Sullivan, E. V. 2004. Perceptual Learning in Detoxified Alcoholic Men: Contributions From Explicit Memory, Executive Function, and Age. Alcoholism: Clinical & Experimental Research, 28(11), 1657-1665.

http://www.eurekalert.org/pub_releases/2004-11/ace-ach110804.php

New brain cells develop during alcohol abstinence

A rat study has found that the detrimental effect of alcohol on the formation of new neurons in the adult rat hippocampus is followed by a pronounced increase in new neuron formation in the hippocampus within four-to-five weeks of abstinence. This included a twofold burst in brain cell proliferation at day seven of abstinence. The findings may have significant implications for treatment of alcoholism during recovery. The discovery of regeneration of neurons in recovery opens up new avenues of therapies aimed at regeneration of brain cells.

[393] Nixon, K., & Crews F. T. (2004).  Temporally Specific Burst in Cell Proliferation Increases Hippocampal Neurogenesis in Protracted Abstinence from Alcohol. J. Neurosci.. 24(43), 9714 - 9722.

http://www.eurekalert.org/pub_releases/2004-11/uonc-nbc110504.php

Cognitive function of alcohol abuse patients may influence treatment outcome

Years of heavy alcohol consumption are known to impair many abilities generally referred to as “executive functions.” Such functions include judgment, problem solving, decision making, planning, and social conduct. But alcohol affects executive functioning both chronically and acutely. New research has found that alcohol abuse patients show significant deficits in executive functioning (specifically, abstract reasoning, memory discrimination, and effectiveness on timed tasks) during the critical first weeks of abstinence. The finding has implications for treatment programs, as the early phases of most treatment programs for alcohol abusers commonly require working in groups, making plans for the future, inhibiting behaviors related to their addiction, and remembering specific things. It is suggested that clinicians should scale down their expectations of what patients can do until more of their executive functioning comes back. The researchers are now intending to explore how long it takes the majority of people to regain most of their executive functioning.

[194] Zinn, S., Stein R., & Swartzwelder S. H. (2004).  Executive Functioning Early in Abstinence From Alcohol. Alcoholism: Clinical and Experimental Research. 28(9), 1338 - 1346.

http://www.eurekalert.org/pub_releases/2004-09/ace-cco090504.php
http://www.eurekalert.org/pub_releases/2004-09/dumc-cfo091004.php

Brain damage found among heavy social drinkers

Almost all knowledge about brain damage due to chronic alcohol consumption has been gathered from alcoholics, generally toward the end of an institutionalized treatment program or many months into abstinence. A new study however, uses magnetic resonance technology to examine brain damage in heavy drinkers who are not in treatment and function relatively well in the community. The study found that frontal white matter NAA – generally considered to be a marker of neuronal damage – was lower in heavy drinkers than light drinkers, and was associated with lower executive and working memory functions. Some of the behaviors that could be associated with the metabolite changes include the inability to apply consequences from past actions, difficulties with abstract concepts of time and money, difficulties with storing and retrieving information, and frequently needing external motivators.

[220] Weiner MW, Meyerhoff DJ, Blumenfeld R, Truran D, Lindgren J, Flenniken D, Cardenas V, Chao LL, Rothlind J, Studholme C. Effects of Heavy Drinking, Binge Drinking, and Family History of Alcoholism on Regional Brain Metabolites. Alcoholism: Clinical and Experimental Research [Internet]. 2004 ;28(4):650 - 661. Available from: http://dx.doi.org/10.1097/01.ALC.0000121805.12350.CA

http://www.eurekalert.org/pub_releases/2004-04/ace-sab040704.php

Even small amounts of alcohol or anesthetics may damage the developing brain

Mouse studies suggest that even small amounts of alcohol or anesthetic drugs can trigger nerve cell death in the developing brain. The brain appears most sensitive to this effect during the development stage known as the brain growth spurt. In humans this lasts from about the sixth month of pregnancy to a child's third birthday. Nerve cells are genetically programmed to commit suicide if they fail to make synaptic connections on time. Alcohol and anesthetic drugs interfere with the brain's neurotransmitter systems and with the formation of those synaptic connections, automatically activating a signal within the neuron that directs it to commit suicide.

Olney, J.W. 2004. Perinatal Drug/Alcohol Exposure and Neuronal Suicide – Public Health Implications. Paper presented February 14 at the annual meeting of the American Association for the Advancement of Science in Seattle.

http://www.eurekalert.org/pub_releases/2004-02/wuso-sao021104.php

Hippocampal damage seen in those with alcoholic memory disorder and those with Alzheimer's

A comparison between the brains of five men with alcoholic Korsakoff's syndrome and the brains of men with Alzheimer's disease as well as the brains of healthy men, found that the brains of all Korsakoff's patients and Alzheimer's patients were comparable in significant volume loss in the hippocampus. Greater hippocampal damage (for Korsakoff's patients) and smaller hippocampal size (for Alzheimer’s) was correlated with poorer memory performance. It is suggested that, although there are of course a number of differences between these disorders, the nature of the memory impairment may be the same. Awareness of the similarities may help detection of both disorders.

[262] Sullivan, E. V., & Marsh L. (2003).  Hippocampal volume deficits in alcoholic Korsakoff's syndrome. Neurology. 61(12), 1716 - 1719.

http://www.eurekalert.org/pub_releases/2003-12/aaon-seu121503.php

Alcohol damages day-to-day memory function

A new study involving 763 participants (465 female, 298 males) used self-report questionnaires: the Prospective Memory Questionnaire (PMQ), the Everyday Memory Questionnaire (EMQ), and the UEL (University of East London) Recreational Drug Use Questionnaire, and found that heavy users of alcohol reported making consistently more errors than those who said that they consumed little or no alcohol. More specifically, those who reported higher levels of alcohol consumption were more likely to miss appointments, forget birthdays and pay bills on time (prospective memory), as well as more problems remembering whether they had done something, like locking the door or switching off the lights or oven, or where they had put items like house keys. The study also found a significant increase in reported memory problems by people who claimed to drink between 10 and 25 units each week in comparison to non-drinkers – this is within the ’safe drinking’ limits suggested by U.K. government guidelines.

[1042] Ling J, Heffernan TM, Buchanan T, Rodgers J, Scholey AB, Parrott AC. Effects of Alcohol on Subjective Ratings of Prospective and Everyday Memory Deficits. Alcoholism: Clinical and Experimental Research [Internet]. 2003 ;27(6):970 - 974. Available from: http://dx.doi.org/10.1111/j.1530-0277.2003.tb04422.x

http://www.eurekalert.org/pub_releases/2003-06/ace-add060903.php

Study of alcoholics reveals connection between cerebellum and prefrontal cortex

Two functions commonly compromised by chronic alcoholism are executive functions (such as problem solving, putting things in order, working memory, doing multiple tasks at once) and balance (the ability to walk a straight line or stand on one foot, especially with eyes closed or in the dark). Executive functions are primarily processed in the prefrontal cortex, while balance and postural stability are functions of the cerebellum. Previous studies have shown that the prefrontal cortex and regions of the cerebellum are especially vulnerable to the effects of chronic alcoholism. Although these areas are spatially far apart (the former in the frontal lobes, the latter in the hindbrain), they are connected in a variety of ways, most particularly through the pons and the thalamus. An imaging study of 25 nonamnesic alcoholic men suggests that these connections may compound the damaging effects of alcohol on these brain regions, and that the cerebellum, through these connections, can exert a significant effect on functions of the prefrontal cortex.

[356] Sullivan, E. V. (2003).  Compromised Pontocerebellar and Cerebellothalamocortical Systems: Speculations on Their Contributions to Cognitive and Motor Impairment in Nonamnesic Alcoholism. Alcoholism: Clinical and Experimental Research. 27(9), 1409 - 1419.

http://www.eurekalert.org/pub_releases/2003-09/ace-amc090803.php

Alcoholics' cognitive impairment associated with impaired reaction to stress

The body secretes a hormone called cortisol in response to stress. Areas of the brain involved in memory and problem-solving are responsive to cortisol. A new study has found impaired release of cortisol in recently detoxified alcoholics when performing two tasks known to induce stress: mental arithmetic problems and a "cold pressor" task, which requires submerging one hand in ice water for 90 seconds. This was associated with lower scores on measures of problem-solving ability and memory. The study also found that, among alcoholics, the number of withdrawals from alcohol was the strongest predictor of memory impairments, but not of problem-solving ability. The greater the alcoholics' relative cortisol levels were during alcohol withdrawal, the more likely they were to have low scores on one of the problem-solving tests. Nonalcoholic participants showed a connection between higher post-stress cortisol levels and impaired memory, a finding supported by earlier research.

[340] Errico, A. L., King A. C., Lovallo W. R., & Parsons O. A. (2002).  Cortisol Dysregulation and Cognitive Impairment in Abstinent Male Alcoholics. Alcoholism: Clinical and Experimental Research. 26(8), 1198 - 1204.

http://www.eurekalert.org/pub_releases/2002-08/cfta-air080902.php