New pediatric research beacon for larger studies

December 1, 2005

Harrison Hot Springs, British Columbia — According to Robert Sidbury, M.D., two of the most important pediatric studies published this year investigated the alleged connection between isotretinoin and depression, thoughts of suicide and even suicide itself among some teenage users being treated for acne.

Dr. Sidbury, assistant professor, department of pediatrics/division of dermatology, University of Washington School of Medicine, Seattle, also cites results of a study of topical sunflower seed oil and Aquaphor (Beiersdorf) use in premature Bangladeshi infants to decrease likelihood of nosocomial infection.

Isotretinoin study

The researchers used a self-reporting depression instrument to measure degree of depression in three-to four-month follow-up visits.

"Of the 101 patients who completed this study, there was found to be no increase in the prevalence of depression symptoms in the isotretinoin group," Dr. Sidbury says. "This was an uncontrolled, small trial and more and larger studies are needed before any real conclusions can be drawn about whether isotretinoin can cause depression or suicidal ideation; however, any good negative studies with regard to this important question are reassuring.

Ultimately, however, the standard of care remains the same: Always screen patients - especially teenagers - for depression symptoms, be very selective when prescribing isotretinoin, and be vigilant in follow-up for developing signs of depression, he says.

Second study

Another isotretinoin-related study appeared in the American Journal of Psychiatry, and focused on functional brain imaging in acne patients treated with isotretinoin, Dr. Sidbury says.

"This was a prospective, unblinded, non-randomized trial of 28 patients ages 18 to 50 with refractory acne, treated with a four-month course of either oral antibiotic or isotretinoin," Dr. Sidbury says. "PET scans were performed both before and after treatment, with the goal of making a correlation between brain metabolism and behavioral and epidemiologic variables."

The study's results, according to Dr. Sidbury, showed no difference in depressive symptoms between the isotretinoin and oral-antibiotics groups.

The greatest imaging changes were in isotretinoin patients who developed a headache, though the significance of this finding is unclear, he says. However, in the isotretinoin group only, PET scanning revealed significantly decreased levels of brain metabolism in regions of the brain thought to mediate symptoms of depression.

"This small, unrandomized study is not conclusive regarding the association between isotretinoin and depressive symptoms, but it does suggest biologic plausibility to the association."

Dr. Sidbury notes that one significant problem with this study was poor matching for confounding variables between groups.

Topical sunflower oil

Another recent study Dr. Sidbury cited appeared in Lancet and focused on the effects of treatment with topical sunflower oil on nosocomial infections in preterm infants.

"This was a controlled, randomized comparison trial of topical sunflower-seed oil and Aquaphor in Bangladeshi infants born before the thirty-third week of pregnancy," Dr. Sidbury says. "One hundred fifty nine infants were treated with the sunflower oil, 157 with Aquaphor. Results showed that the infants treated with sunflower oil were 41 percent less likely to develop nosocomial infection. The Aquaphor group also had decreased rates of infection, but not as statistically significant as the sunflower-seed oil group."