One in four adults reported a change in alcohol use almost immediately after stay-at-home orders were issued, according to a study of twins led by Washington State University researchers.

The study, published recently in Frontiers in Psychiatry, surveyed more than 900 twin pairs from the Washington State Twin Registry from March 26 to April 5, 2020, just after stay-at-home orders were issued in Washington on March 23. An estimated 14% of survey respondents said they drank more alcohol than the week prior and reported higher levels of stress and anxiety than those who did not drink alcohol and those whose use stayed the same.

“We expected that down the road people might turn to alcohol after the stay-at-home orders were issued, but apparently it happened right off the bat,” said Ally Avery, lead author of the study and a scientific operations manager at WSU’s Elson S. Floyd College of Medicine. “It shows the need to make sure there is more mental health support since it had an impact on people right away.”

Surprisingly, the study showed that the 11% who decreased their drinking also had higher levels of stress and anxiety than the groups with no change–suggesting that any change in alcohol use may be associated with mental health issues.

The study did not examine the reasons behind the link between a decrease in drinking and increase in stress and anxiety, but Avery said one possibility is that these were social drinkers who were missing out on after-work happy hours and other occasions where they drank with friends.

The researchers conducted the study with twins so that they could look at whether changes in alcohol use and mental health were mediated by genetic or shared environmental factors since twins raised in the same family share many formative experiences. Twins also have common genetics with fraternal twins sharing approximately half of their genes while identical twins share all of their genes.

In this study, the researchers found that the association between changes in alcohol use, and stress and anxiety were relatively small and confounded by between-family factors and demographic characteristics.

Still the link between the pandemic, alcohol use, and stress and anxiety is concerning, Avery said. The researchers are continuing to survey this group at longer intervals to see if the increased drinking persists and whether it becomes a bigger problem.