The lawyer knew something was wrong with her 61-year-old mother.

She had begun showing up for appointments two hours early. Or two hours late. She was paying less attention to how she looked. She'd had two wrecks in quick succession on her way to work as a judge's administrative assistant.

The lawyer, who works in a small town on the outskirts of Baltimore, knew her mother drank a fair amount at night, but she also knew her mother was still getting promotions.

She suspected depression. A therapist agreed. When medication didn't clear up the cognitive problems, though, the lawyer took her mother for a full neuropsychological evaluation.

The surprising diagnosis: alcohol-related dementia.

A special MRI showed shrinkage in parts of the brain known to be damaged by heavy drinking. She had visual and spatial problems, plus poor memory and problems with executive function, the cognitive skills that help us make and carry out plans, her geriatric neuropsychologist, Nicole Absar, explained.

Chronic alcohol use, she said, can lead to cognitive problems that are hard to distinguish from other, better-known forms of dementia. The condition is probably underdiagnosed and definitely understudied.

It matters because, unlike other dementias, which get worse over time, alcohol-related brain damage doesn't progress if people stop drinking. It can get better.

George Koob, director of the National Institute on Alcohol Abuse and Alcoholism, said the question of how alcohol exposure affects the aging brain deserves more attention, and he plans to make it a priority.

"It's something that we haven't put much energy into," he said, "something that I am personally quite interested in."

This goes beyond older drinkers because alcohol abuse transcends age. Koob is concerned about the long-term effects of binge drinking, especially in high school and college students whose brains are still forming. Drinking disproportionately affects the frontal lobe, a brain region needed not only for good decision-making but for resisting addiction. A related question is whether those who drink heavily when young - or who used illicit drugs - are more likely to have cognitive problems later in life when their brains are more vulnerable because of age and other illnesses.

Aaron White, senior scientific adviser to Koob, said there is evidence that baby boomers drink more than the generations above and below them and have been slower to slack off on the drinking as they have aged. "Together, such findings suggest that baby boomers are bringing their alcohol use with them into older ages," he said. They also used and continue to use more drugs.

Tony Rao, a London geriatric psychiatrist, has been raising the alarm in England about a potential wave of alcohol-related brain problems as more baby boomers reach retirement age. He outlined his concerns last year in the respected medical journal Lancet Psychiatry.

Though the number of people diagnosed with alcohol-related dementia is small, Rao said that it was growing faster than the aged population and that most doctors weren't looking for it.

"Alcohol is the last thing on people's minds," Rao said, "when they look at this chronically damaged brain."

He said his cause had not been embraced. Some have criticized his "nanny state" call for less drinking. "Everywhere you go . . . you've got barriers to effective research, effective policy-making, and effective assessment," he said.

'The entire body'

The role alcohol plays in late-life cognitive impairment is a controversial subject.

There is general agreement about Wernicke-Korsakoff syndrome, a kind of brain damage caused by a vitamin deficiency from poor nutrition. The lawyer's mother was diagnosed with a variant of that syndrome. Experts say it is becoming less common.

Some question whether alcohol directly causes other dementia symptoms and suggest it more likely contributes indirectly through liver damage, poor diet, lack of exercise, and accidents.

"Clearly, heavy alcohol use is bad for the entire body," said Kristine Yaffe, a prominent dementia expert and professor of psychiatry and neurology at the University of California San Francisco.

Though Yaffe often wonders what drinking has done to patients, she remains skeptical of alcohol as a dementia cause.

"I think the field is confusing," she said.

It is clear that alcohol in higher quantities causes brain damage throughout the life span, but experts don't know how much of that damage is permanent or whether more moderate drinking can cause smaller, cumulative injuries. It is also not clear how alcohol interacts with other causes of age-related thinking problems.

All our brains shrink and work more slowly in some realms as we age. Then there are forms of dementia caused by the buildup of misfolded proteins: Alzheimer's disease, Lewy body dementia, and frontotemporal dementia. Vascular dementia, caused by poor circulation and small strokes, is another common reason for poor cognitive functioning.

Absar, who treated the lawyer's mother at her practice at the Copper Ridge Memory Clinic in Sykesville, Md., said it was often difficult to tell which or how many kinds of dementia a patient has. Although dementia caused only by alcohol is unusual, she suspects alcohol plays a role in about a quarter of the dementia cases she sees.

Drinking is clearly not a good idea for people who already have dementia, and, in general, older bodies don't metabolize alcohol as well as young ones.

"A glass of wine now is like drinking three glasses of wine when you're 20," said Dan Kaufer, chief of cognitive and behavioral neurology at the University of North Carolina Memory Disorders Program.

David Oslin, a University of Pennsylvania psychiatrist who has studied alcohol abuse and dementia, examined dementia in a VA nursing home. His study, done in 2003, is still one of the few on the topic. Ten percent of the patients had alcohol-related dementia, compared with 16.5 percent who had Alzheimer's disease, 29 percent with vascular dementia, and 44 percent with some mixture of dementias. "These folks end up being under the radar or labeled with Alzheimer's disease," he said.

Oslin looked at very heavy drinkers, men who drank 35 drinks a week for five years or women who had 28 drinks a week.

"It's very unlikely that you would get this from being a social drinker," he said.

No absolutes

There is evidence that light to moderate drinkers (a drink a day for women, two for men) have better health than abstainers, largely because of better cardiovascular health. In general, what's good for the heart is good for the brain.

There is no absolute cutoff for safe - or damaging - drinking. The danger point may vary with other health problems and individual characteristics.

Most of the work on how alcohol damages the brain has been done in recovering alcoholics.

Catherine Fortier, a clinical neuropsychologist at Harvard Medical School, has found reduced gray matter or nerve cells across the entire brain in that group. The damage was worst in the frontal temporal lobes. There was also a reduction in white matter - fibers that connect parts of the brain - especially in the frontal lobe.

That kind of damage has been associated with deficits in impulse control or the ability to change thinking or behavior, problems that also are seen in heavy drinkers.

Fortier's research found some improvement in the brains of recovering alcoholics, particularly younger ones.

"People who stopped drinking prior to 50 had greater recovery than people who stopped after that," she said.

Edith Sullivan, a neuropsychologist at Stanford University, compared brain structure and functioning in recovering alcoholics and normal drinkers as they aged. The alcohol abusers started out with more problems in connections between parts of the brain, but everyone declined over time. The alcoholics who started drinking heavily again declined faster than the normal agers. Those who stayed on the wagon got better, drawing closer to the nonalcoholics.

Though the brain can improve when drinking stops, Sullivan said, some functions remain fragile, including balance, working and spatial memory, and the ability to inhibit emotional responses like, say, anger at the boss. She found long-lasting balance problems. Caregivers and alcoholics themselves should be alert to the risk of falls in this group.

Sullivan found that recovering alcoholics who had learned to perform well on tests of working spatial memory skills were not using their brains as efficiently as members of a control group. How that will affect them later in life is unknown.

She is a little worried about people who are now living longer, retiring with some money, and growing accustomed to a few drinks at the country club or even at senior housing facilities, which now host happy hours.

She drinks a glass of red wine most nights herself, but thinks everyone should take one night a week off from alcohol. If you find you miss it too much that night, it's a sign you probably need to take more nights off.