Drug May Cut Psoriasis Depression

Depression, Fatigue Eased in Study of Arthritis Drug, Enbrel

From the WebMD Archives

Dec. 15, 2005 -- Enbrel, a drug approved to treat rheumatoid and psoriatic arthritis, might also help psoriasis patients mentally and physically.

The finding, published in The Lancet, comes from a study of 618 people with moderate to severe psoriasis.

The study's main goal was to test Enbrel as a psoriasis skin treatment. The researchers also noticed a drop in depression and fatigue in patients who got Enbrel instead of a fake drug.

The researchers included Stephen Tyring, MD, of the dermatology department at the University of Texas Health Science Center, and Ranga Krishnan, MD, a professor of psychiatry and behavioral sciences at Duke University Medical Center.

'Exciting' Science

"While depression scores improved, we cannot be sure why," Krishnan says, in a news release. "Our next step is to run this type of trial in people who have depression but not psoriasis."

"At this point, no one should run to their doctor and ask for this drug for depression," Krishnan continues. "However, the science is very exciting to us."

Enbrel blocks an inflammatory chemical called tumor necrosis factor alpha (TNF-alpha). TNF-alpha has been linked to fatigue and sleepiness, and it may also be connected to depression, according to background information in the study.

Psoriasis and Depression

Psoriasis is a common, chronic condition marked by patches of itchy, scaly, and sometimes inflamed skin, often on the elbows, hands, feet, scalp, or back.

Some psoriasis cases are mild. Others are severe, leaving patients feeling self-conscious, isolated, and depressed.

"Depression, substance abuse, and suicidality are common and problematic in patients with psoriasis," write Tyring and colleagues.

Depression is also common in people in general and depression treatments (including talk therapy and the use of antidepressants) are often helpful.

Psoriasis Study

The Enbrel study lasted three months. During that time, all patients got two weekly injections.

Half of the patients got shots of Enbrel. The others got shots containing no medicine (placebo). No one knew which patients received Enbrel.

Patients rated their depression and fatigue at the study's start and during the fourth, eighth, and 12th weeks. They were also screened by a researcher for depression.


Depression, Fatigue Before Treatment

At the study's start, about a third of participants in both groups appeared to be mildly to severely depressed.

The patients also reported more fatigue than the general public, the researchers note.

Depression, Fatigue After Treatment

Depression and fatigue eased for both treatment groups, with bigger gains reported for patients taking Enbrel.

By the study's end, depressed patients had significant improvements in areas including sexual symptoms, interest, appearance, and work or other activities.

More patients taking Enbrel also reached the study's goal for improvement in joint and skin problems caused by psoriasis. That goal was reached by 47% of the Enbrel group, compared with 5% of the placebo group.

Side Effects

The most common side effects were reactions at the injection sites. Infections were more common in the Enbrel group but not by much, the researchers note.

No patients became suicidal during the study. If any had become suicidal, those patients would have been removed from the study and given psychiatric care.

Surprising Data

"Surprisingly, the majority of patients in this study did not have significant depression at baseline, by contrast with what is known about the general psoriasis population," write Tyring and colleagues.

They suggest that the study's design might partly explain that. Patients were excluded if they had a history of psychiatric disorders that might interfere with study participation.

The study was partly designed by Immunex, which invented Enbrel. Immunex and Wyeth Research funded the study. Amgen, which now owns Immunex, provided "editorial assistance" in writing the paper, the researchers write.

WebMD Health News Reviewed by Ann Edmundson, MD, PhD on December 15, 2005


SOURCES: Tyring, S. The Lancet, Dec. 14, 2005; online edition. WebMD Medical Reference: "Psoriasis Overview." News release, Duke University Medical Center
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