(Reuters Health) - High-risk drinking among U.S. adults increased about 30 percent between 2001-2002 and 2012-2013, according to a new study that called the proportion Americans developing alcohol dependence a “public health crisis.”

The study defined high-risk drinking as regular consumption of four drinks a day for women or five for men. U.S. adults with an alcohol use disorder, defined as a dependence on alcohol, also increased nearly 50 percent during the period studied, researchers found.

Increases in drinking were greatest among women, older adults, racial and ethnic minorities and people with low education and income levels, the study found.

“Light drinking has been shown to be helpful for people’s health overall, but heavy drinking can lead to some harms and impairment,” said study’s lead author Deborah Hasin, of Columbia University in New York.

Heavy drinking and alcohol use disorders are risk factors for health issues such as high blood pressure, heart problems, stroke, cancer and infections, Hasin and colleagues wrote in the medical journal JAMA Psychiatry.

Past studies found alcohol use in the United States declined between the 1970s and early 1990s. More recent research, however, has suggested increases in alcohol use between the 1990s and early 2000s.

The new findings are based on face-to-face interviews with nationally representative samples of adults in 2001-2002 and 2012-2013.

The proportion of adults using alcohol during the previous year increased from about 65 percent to about 73 percent over the study period. Drinking more than four or five alcoholic beverages in one sitting also increased from about 10 percent to about 13 percent, researchers found.

The proportion of adults who met the criteria for an alcohol use disorder increased from about 9 percent to about 13 percent.

“People need to really take some of the information about the potential harms of heavy drinking into account when determining when and how much to drink,” Hasin said.

“Policymakers and health professionals need to be aware of this, too,” she added.

The study does not explain why alcohol drinking and abuse increased, but researchers suggest some explanations could be changing social norms and its use as a coping device.

“Researchers will be trying to examine why these changes are happening,” Hasin said.

SOURCE: bit.ly/2uoeMc0 JAMA Psychiatry, online August 9, 2017.