What Is the Impact of Psoriasis on Patients' Mental Health?

Patients with psoriasis often have other physical diseases, and these somatic comorbidities can have a bigger effect on the patient’s mental health than the skin symptoms from their psoriasis, according to a study published in JAMA Dermatology.

Researchers in Sweden used a population-based registry data from Swedish patients in routine clinical care. Patients with psoriasis were matched with control participants without psoriasis by age, sex, and municipality. All participants in the study were free of existing psychiatric illness (PI).

“Little is known about the independent risks imparted by skin psoriasis compared with somatic comorbidity on the development of PI or whether they have additive or synergistic associations,” the authors explained.

A total of 93,239 patients with skin psoriasis and 1,387,495 control participants were enrolled between January 2005 and December 2010. Patients with psoriasis had their first diagnosis during the study period. For the study, PI was a composite measure of depression, anxiety, and suicidality, which was composed of suicidal ideation, suicide attempt, and completed suicide. The Elixhauser Comorbidity Index (ECI) and the Charlson Comorbidity Index (CCI) were used to calculate comorbidity profiles for each patient in the year before baseline.

The authors found that the interaction between skin psoriasis and ECI and between skin psoriasis and CCI were not statistically significant, which indicated skin psoriasis and somatic comorbidities do not act synergistically. The authors noted that “both skin psoriasis and somatic comorbidity are independent risk factors for PI onset.”

Patients who were sicker (with both skin psoriasis and somatic comorbidity) had the highest rate of incident PI. However, patients with skin psoriasis but no somatic comorbidity actually had a lower rate of PI onset compared with the control participants who had somatic comorbidity.

The authors speculated that the somatic comorbidities in the ECI and CCI may be considered severe compared with skin psoriasis, which explains why they may contribute more to PI onset. They also noted that since somatic comorbidity is broadly defined, patients may have multiple diseases compared with the patients with skin psoriasis and no somatic comorbidity who only had 1 recorded disease.

They recommended that future research understand the interaction of clinical severity with somatic comorbidity and PI in patients with psoriasis. They also noted that the findings support use of holistic patient management.

"I would be delighted if our study could support the trend towards a more holistic view on psoriasis care," coauthor Marcus Schmitt-Egenolf, MD, PhD, dermatologist and professor at Umeå University, said in a statement. “At the doctor's office, lifestyle factors should be discussed in the awareness that individual responsibility may be limited by available personal and community resources. Such an approach may improve the complete triad of psoriasis—skin symptoms, somatic and mental health alike.”

Reference

Geale K, Henriksson M, Jokinen J, Schmitt-Egenolf M. Association of skin psoriasis and somatic comorbidity with the development of psychiatric illness in a nationwide Swedish study. JAMA Dermatol. Published online June 3, 2020. doi:10.1001/jamadermatol.2020.1398