Acne drug affects brain function.

The oral medication Accutane, known generically as isotretinoin, is one of the most popular ways to treat severe acne. However, anecdotal complaints linking isotretinoin to depression and suicide have left some doctors and patients concerned about the drug's safety.

J. Douglas Bremner of Emory University Hospital in Atlanta and his colleagues reasoned that if isotretinoin does play a role in causing depression, the drug must exert some noticeable effect on the brain. To test that idea, the researchers administered positron emission tomography (PET) scans, which measure activity in regions of the brain, to a group of 28 people with acne. A battery of psychological tests beforehand found no correlation between severity of the participants' acne and whether they felt depressed.

The volunteers then received either isotretinoin or a course of oral antibiotics, another common treatment for acne. After 4 months, Bremner's team gave each person a second PET scan.

The researchers found that people who took isotretinoin showed decreased activity in the orbitofrontal cortex, a brain area thought to control mood and social interaction. Participants who took antibiotics showed no change in any brain region between the first and second PET scans.

Bremner acknowledges that these findings are preliminary, but he argues that doctors should keep an eye out for depression as a possible side effect of isotretinoin.