About 1 in 5 people with psoriasis also have depression, and the rate is similar for anxiety, according to a new study. The report published in Psychiatric researchis believed to be the first to systematically estimate the worldwide prevalence of psychiatric comorbidity among people with this skin condition.
The study authors say an estimated 125 million people worldwide have psoriasis, and many of these people experience co-morbidities such as cardiovascular disease, diabetes and metabolic syndrome. There is also evidence that people with psoriasis are more likely to have co-morbid mental illnesses, but the researchers said there is currently a lack of comprehensive understanding in the scientific community about the exact prevalence of such co-morbidities.
“Although systematic reviews of psoriasis and its comorbidities such as depression, anxiety, and bipolar disorder have been conducted, no studies have systematically focused on the epidemiology of mental disorders, including depression, anxiety, and suicide,” they wrote.
They decided to search 5 academic and medical databases to find studies that examined the prevalence of mental health comorbidities in people with psoriasis. They identified 56 studies published between 1986 and the study’s cut-off date in May 2022.
After pooling the data, they found that the prevalence of diabetes in people with psoriasis was 20%; of anxiety, 21%; and suicide – 0.77%. People in North America were more likely to have depression, and those in South America were more likely to experience anxiety, the authors added. Suicide data were only included in studies of people in Europe and North America, they noted.
In terms of incidence per 1,000 person-years, the authors found 42.1 cases of depression, 24.7 cases of anxiety, and 2.6 cases of suicide. The researchers said these data support the idea that mental health should be a key factor in the treatment of people with psoriasis.
“Due to changes in skin appearance, patients with psoriasis are more likely to experience a high psychosocial burden, including comorbid depression, anxiety, and suicidal ideation,” the authors said. “Furthermore, the medical community and the public have recognized that mental health significantly impacts the quality of life of patients with psoriasis.”
The researchers said the link between psoriasis and depression may be related to pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukins 17 and 23.
“Some studies have shown that TNF-α antagonists, which can be used to treat psoriasis, are equally effective in patients with depression,” they note.
The authors add that there may also be a link between systemic inflammation and suicide risk.
“The molecular mechanisms underlying the comorbidity of psoriasis and anxiety may be attributed to sympathetic nervous system disturbances and abnormal expression of neuropeptides, including calcitonin gene-related peptide, substance P, and nerve growth factor,” they write them.
Still, although the authors say their report helps show the links between psoriasis and mental disorders and the range in prevalence of comorbid mental disorders from region to region, it is not designed to understand the underlying biological causes of the associations. Those answers, they said, will require further study.
reference
Liu L, Lin N, Yu Y, et al. Epidemiology of mental health comorbidity in patients with psoriasis: an analysis of trends from 1986 to 2019. Psychiatry Res. Published online January 23, 2023. doi:10.1016/j.psychres.2023.115078