HIV-positive gay men's fluctuations in mood are linked to their sexual risk taking, according to a new study from Columbia University's Mailman School of Public Health. Publishing their findings in Health Psychology, researchers gave weekly surveys over a six-week period to 106 sexually active, HIV-positive men who have sex with men living in New York City. At the week 1, 3 and 5 marks, the men answered questions about their sexual behavior, depression and well-being during the previous week.

Sixty-six percent of the participants reported intercourse without a condom during the previous two-month period. Eighty-one percent of them had sex with multiple partners.

While past research has not found that depression leads to higher rates of condomless sex—and has even suggested that being down in the dumps reduces such behavior—this study is unique in its approach: It examined not just mood, but also deviations from an average mood over time and how they correlate to risky sex.

During the weeks when participants' depression was higher than their average individual levels, they were 71 percent more likely to have any episode of intercourse without a condom and 149 percent more likely to have an episode of condomless sex with an HIV-negative partner. On the other hand, during the weeks when the participants' positive mood was higher than their individual average, the likelihood of any sex without latex was 60 percent lower and serodiscordant sex without a condom was 58 percent lower.

As Patrick A. Wilson, PhD, an associate professor of sociomedical sciences at the Mailman School and the study's lead author, said in a release: “We all have bad days and good days, and bad weeks and good weeks. That's life. But it turns out that how moods change can be a big factor in influencing condom use.”

To read a press release on the study, click here.

To read the study abstract, click here.