A new study out of Yale University has produced a surprising discovery that HIV-positive men may be more sensitive to alcohol than those who are not.

The findings were published in the latest issue of the journal AIDS and Behavior. Researchers at Yale and the VA Pittsburgh Healthcare System compiled data from 2,600 men who were enrolled in a Veterans Aging Cohort study and asked how many drinks it took to “feel a buzz or high” from alcohol. The men with detectable HIV needed a quarter less of a drink on average to feel a buzz than those who were either uninfected or had suppressed HIV.

“The reason for the difference is not clear,” said Dr. Amy C. Justice, professor in medicine and public health at Yale. “It may be that HIV-positive men are more sensitive to alcohol for some reason or that more alcohol is retained in the blood of those men.”

The new findings could play a role in how regularly HIV-infected men take their medications. Justice suggested that “once people have HIV, alcohol makes it less likely they will take their antiretroviral medications.” Considering that both alcohol and the HIV virus damage both the liver and immune system, this combination can produce significant damage.

Separate studies have found that other substances can also accelerate the progression of the disease and increase rates of new transmissions. A study released in March 2014 by the University of California, San Diego found that crystal meth users displayed faster progressions to full blown AIDS and a higher risk of cognitive impairment. The findings also produced evidence that those who used meth may also have a deeper HIV DNA reservoir than those who did not.

However, the scientists were not able to explain the link between meth use and faster progressions of HIV. They also concluded that despite 40% of study participants using other drugs including marijuana and cocaine, these substances did not contribute to the progression of HIV or risk of cognitive impairment.