Alcohol itself doesn’t have a detrimental effect on CD4 cell counts for people taking antiretroviral (ARV) therapy, a recent study concludes. But this isn’t a simple carte blanche to drink up, say its authors, as well as other experts on the topic of substance use within the HIV population.

“Among all the factors that affect non-adherence to medications, alcohol is the most robust,” said Seth Kalichman, a professor of psychology at the University of Connecticut and the lead author of a related study. Looking at people with HIV who are taking ARVs and who also drink alcohol, he found that half of them purposefully skipped their medications when drinking.

Previous research has documented that alcohol’s disorienting effects significantly lower adherence rates. It has also uncovered that a majority of people living with HIV in the United States falsely believe that ARVs and booze are a harmful mix—a notion that essentially amounts to a wives’ tale. (Important exceptions are those coinfected with hepatitis B or C, for whom any alcohol consumption is highly toxic to the liver.)

Participants in Kalichman’s study who held these erroneous beliefs about toxicity were more likely to skip or stop their HIV meds while drinking. What’s more, they were less likely to maintain an undetectable viral load and more likely to have a CD4 count below 200.

Kalichman said that health care providers urgently need to intervene and challenge these misconceptions among their patients.