Psoriasis Severity Does Not Appear to Increase Depression Risk

While previous studies have identified a link between psoriasis—a debilitating skin condition that affects about 4 percent of the population—and depression, a study published September 30 in JAMA Dermatology suggests that the severity of psoriasis does not influence the risk of depression.

The findings suggest that “[t]he degree of depression may be more tied to patients’ perception of how society views their physical appearance, as opposed to how severe the psoriasis is objectively,” lead author Roger Ho, M.D., M.P.H., of the Ronald O. Perelman Department of Dermatology at New York University School of Medicine, said. “This should encourage physicians to screen all psoriasis patients for depression, regardless of how mild the skin problems may appear.”

Ho, along with his NYU dermatology colleagues Brandon Cohen, B.S., and Kathryn Martires, M.D., examined patient data available as part of the National Health and Nutrition Examination Survey. They compiled information on more than 12,000 patients collected from 2009 to 2012, which included 351 cases of psoriasis and 968 cases of depression.

The prevalence of depression was about twice as high among psoriasis patients (16.5 percent) compared with people without a history of psoriasis (8.9 percent). This twofold risk increase remained the same even when factoring in other potential risk factors, such as cardiovascular problems.

Psoriasis is an autoimmune disorder, and it has been linked to an increased risk of heart attacks and strokes—both of which also increase the risk of depression. Yet the psoriasis patients with a history of heart attacks or strokes had no increased risk of depression compared with psoriasis patients with no such history, suggesting that psoriasis’ depression risks are independent of its cardiovascular interactions.

Also, psoriasis patients were divided into two groups: those with limited psoriasis and those with extensive psoriasis; there was no significant difference in depression rates between these groups (18.4 percent for limited psoraiasis and 23.1 percent for extensive).

“Overall this was a very well-designed study that considered a lot of variables, with the exception of testing whether psoriasis medications had any effect on depression,” James Bourgeois, O.D., M.D., a clinical professor of psychiatry at the University of California, San Francisco, told Psychiatric News. He was not involved in the study.

“It is also nice to see some attention paid to an illness that is chronic but not necessarily life-threatening, and highlighting that such conditions also have a strong psychiatric burden,” he continued.

Moving forward, Bourgeois thinks that some prospective studies would be worthwhile, as researchers continue to recognize the bidirectional relationship between mental and physical health problems.

“We see it frequently in chronic pain; the pain leads to depression, which in turn exacerbates the level of pain,” Bourgeois said. “It would be interesting to see if depression may likewise influence psoriasis and also test whether actively treating depression might reduce the severity of psoriasis.” ■