In a recent poll, 77% of you said you sometimes suffer from depression. If you’re on antidepressants and HIV meds, you need to know how they’ll interact. Interactions can drop or raise med blood levels, altering drug efficacy (even threatening resistance and treatment failure, in the case of HIV meds) or increasing side effects (such as seizures, in the case of some antidepressants).

POZ investigated how anti-depressants and common herbal mood enhancers mix with HIV med newcomers. Here’s the blues news (with some background):

Many interactions happen when drugs are processed by the same CYP450 enzymes in the liver. Sharing CYP450 causes one drug to boost another’s levels; that’s how the protease inhibitor Norvir (ritonavir) lifts other PIs. Norvir is the big culprit in raising other meds, too, says Judith Rabkin, PhD, of New York City’s Columbia University, who studies antidepressants in positive people.

Drug-level raisers: Newly approved PIs Aptivus (tipranavir) and Prezista (darunavir) and the experimental brecanavir—all boosted by Norvir—may raise levels of tricyclics, SSRIs and Wellbutrin (bupropion). That’s because these meds are processed by that same CYP450 enzyme. Experimental CCR5 entry inhibitors maraviroc and vicriviroc use CYP450 too, so they may also boost blues meds. So far, integrase inhibitor MK-0518, like nukes, seems to avoid the problem.

Level droppers: Since older non-nukes can lower some antidepressant levels, the experimental non-nuke etravirine (TMC125) may do so as well. Further study will tell. The herb St. John’s wort can drop levels of both PIs and non-nukes. Testing each experimental HIV med with all existing drugs and supplements, says Rabkin, is “extremely expensive and difficult.”

Uncertain: Supplements like SAM-e and DHEA aren’t FDA-approved or well studied, so interactions with HIV meds are unknown. Beware.

Ask Doc about measuring your blood drug levels and adjusting or switching meds as needed. Mention everything you take: scripts, over-the-counter meds, street drugs and herbs. That’s one way to keep happy.