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A UCalgary study sheds light on psoriatic arthritis

A UCalgary study sheds light on psoriatic arthritis

A new link between psoriasis and depression, and the subsequent development of psoriatic arthritis calls for better mental health assessment

Nearly one million Canadians live with psoriasis. Characterized by red, scaly patches (called plaques) on the skin, psoriasis is often itchy and painful; it can also lead to low self-esteem. People with psoriasis have an increased risk for many major medical disorders, including psoriatic arthritis, an inflammation of the joints that can lead to irreversible joint damage.  In fact, between 10 to 30 per cent of patients with psoriasis develop psoriatic arthritis. 

For years, the rheumatology and dermatology communities have been trying to understand why some patients with psoriasis go on to develop psoriatic arthritis. A team of UCalgary researchers believe they have found a link.

The link between depression and psoriatic arthritis

A multidisciplinary team, led by senior investigator Cheryl Barnabe of the McCaig Institute for Bone and Joint Health and the O’Brien Institute for Public Health, Cumming School of Medicine has found that psoriasis patients who developed depression were at a 37 per cent greater risk of subsequently developing psoriatic arthritis, compared with psoriasis patients who did not develop depression. Their findings were published recently in the Journal of Investigative Dermatology.

Because of the highly visible nature of psoriasis, people with the condition often experience social isolation and depression. Based on recent laboratory work demonstrating that major depressive disorder is associated with increased systemic inflammation, the team of researchers hypothesized that psoriasis patients who develop depression are at increased risk of subsequently developing psoriatic arthritis.

Investigators used a primary care medical records database in the United Kingdom to identify over 70,000 patients with a new diagnosis of psoriasis. Through follow-up records, they identified individuals who subsequently developed depression and those who developed psoriatic arthritis. Patients were followed for up to 25 years or until they developed psoriatic arthritis.

Statistical analysis showed that patients with psoriasis who developed major depressive disorder were at 37 per cent greater risk of subsequently developing psoriatic arthritis compared with patients who did not develop depression, even after accounting for numerous other factors such as age, body mass, other illnesses and use of alcohol.

First author and a MD-PhD Leaders in Medicine student Ryan Lewinson points out that more work is needed to identify the role of both depression and systemic inflammation, which is elevated in depression, in psoriatic arthritis.  "Future studies will need to focus on the mechanisms involved in the relationship between psoriasis, depression and development of arthritis," he says.

Prevention is key

The study highlights the need for heightened prevention, detection and management of depression in patients with psoriasis. According to Barnabe, it’s important to get the study findings out to physicians who treat psoriasis patients. “Addressing depression in patients with psoriasis might keep them from developing psoriatic arthritis, preventing the need for long-term immunosuppression and damage to bones, joints and tendons before it occurs.”

  

Cheryl Barnabe is an Associate Professor with the Division of Rheumatology, in the University of Calgary’s Cumming School of Medicine and a member of the McCaig Institute for Bone and Joint Health and the O’Brien Institute for Public Health. 

Ryan Lewinson completed his PhD in the Biomedical Engineering Program in the Schulich School of Engineering, University of Calgary, and is currently in his final year of medical school in the Cumming School of Medicine.  He receives funding from the Canadian Institute for Health Research, the Canadian Association of Psoriasis Patients and Alberta Innovates.