Alcohol problems affect almost 33 million adults and most have never sought treatment, according to a government survey that suggests rates have increased in recent years.

The study is the first national estimate based on a new term, "alcohol use disorder," in a widely used psychiatric handbook that was updated in 2013.

Five things to know about the research published Wednesday in the journal JAMA Psychiatry:

DEFINING ALCOHOL PROBLEMS

The revised handbook, the DSM-5, defines problem drinkers or those with the disorder as people with at least two of 11 symptoms, including drinking that harms performance at work, school or home, frequent hangovers and failed attempts to limit drinking. Mild problems involve two to three symptoms; severe involve at least six symptoms. The new handbook combined alcohol abuse and dependence, which had been separate disorders, added craving as one symptom and eliminated alcohol-related legal problems as another.

THE NUMBERS

Researchers from the National Institute on Alcohol Abuse and Alcoholism asked 36,000 adults during 2012 or 2013 about lifetime drinking habits, including current or within the past year. About 14 percent of adults were current or recent problem drinkers, or nearly 33 million nationally, and 30 percent — almost 69 million — had been at some point in their lives. Mild drinking problems were the most common, while 14 percent had ever experienced severe drinking problems.

Using the old definition, the rates were 13 percent for current or recent problem drinking and 44 percent for lifetime prevalence — up from 9 percent and 30 percent in the agency's 2001-02 survey.

HEAVY DRINKING

Nearly 40 percent of adults who reported any recent drinking had engaged in binge drinking — downing at least five drinks in a day at least once in the past year, up from 31 percent in the earlier survey. Even heavier drinking also increased but was less common.

WHO'S DRINKING?

Drinking problems were most prevalent among men, whites and Native Americans. Low-income adults, those younger than 30 and those who never married also relatively high rates. Problem drinking also was more common among city dwellers than those in rural areas, while the West and Midwest had higher rates than other regions.

STIGMA & DENIAL

Dr. George Koob, director of the federal agency that did the survey, said it's unclear why problem drinking has increased but that many people underestimate the dangers of excessive alcohol. Many won't seek help because of "stigma and denial," and many don't realize that medications and behavior treatments can help.

"There's a lore that there's only Alcoholics Anonymous out there and that's not true," he said.