Those with hidradenitis suppurativa (HS) are more likely than those without the disease to develop depression or anxiety; however, patients treated with biologics appear to have a lower risk of depression, according to a study recently published in JAMA Dermatology.
HS is a chronic, inflammatory skin disorder that causes painful lesions, scarring and a foul-smelling discharge in areas where skin rubs together, such as the underarms and groin.
Affecting roughly 1% to 2% of the population, mostly women, HS usually begins in late adolescence or early adulthood. However, diagnosis is often delayed by an average of seven years, which can worsen symptoms and contribute to psychological distress.
Beyond the skin, HS is associated with conditions including cardiovascular disease, inflammatory bowel disease (IBD), metabolic syndrome and polycystic ovarian syndrome. These comorbidities are believed to stem from factors such as systemic inflammation, obesity, smoking and genetics.
HS also carries a significant mental health burden.
Studies have found higher rates of depression and anxiety among those with HS compared with the general population, especially among women, smokers and those with alcohol use disorders. Potential drivers include chronic pain, impaired body image, sexual dysfunction and social or economic challenges such as unemployment.
A recent review found that HS patients face elevated risks not only of depression and anxiety, but also of bipolar disorder, psychotic disorders, substance abuse and suicide. Another study reported that those with HS, especially severe cases, often experience poorer sleep, mood and overall quality of life.
Studies have found higher rates of depression and anxiety among those with HS compared with the general population, especially among women, smokers and those with alcohol use disorders.
While these associations are documented, few studies have examined whether disease severity influences mental health outcomes, or whether HS increases the likelihood of recurrent depression and anxiety in those with a prior history.
To look into this association, researchers conducted the nationwide cohort study that used Danish health registries to track all residents of Denmark from January 1, 1997, to December 31, 2022. Data on demographics, education, income, medical conditions, hospital visits and prescriptions were linked using personal identification numbers. HS cases were identified from hospital diagnoses, and participants were considered unexposed until their first HS diagnosis. Controls from the general population were matched 4:1 by age and sex.
The main outcomes were new cases of depression or anxiety, based on hospital records or prescriptions for antidepressants or anxiety medicines. Other factors included income level, lifestyle habits and other health conditions.
HS severity was estimated by treatment type (topical, systemic nonbiologic, or biologic) and the number of HS-related surgeries. Participants were followed from their start date until the first mental health outcome, death, migration or study end. To ensure only new cases were captured, those with depression or anxiety in the three years prior to the index date were excluded.
The analysis included 10,206 patients with HS and 40,125 matched controls. The mean age in both groups was about 38 years, and 69.9% were female. Compared with controls, HS patients had higher rates of alcohol use disorder (5.8% vs 2.6%), smoking (14.0% vs 3.8%), drug use disorder (5.1% vs 0.8%), diabetes, hypertension and IBD. They were also less likely to be in the highest income or education brackets.
It was also found that about 55.5% of patients received systemic nonbiologic drugs, while 6.5% received biologics. Those treated with biologics had the highest prevalence of substance use disorders and IBD.
During follow-up, HS patients had a higher incidence of new-onset depression or anxiety than controls. had a 52% higher overall risk of developing depression or anxiety, with depression risk (HR 1.69) higher than anxiety risk (HR 1.48). The higher risk showed up in all treatment groups, but for those using biologics, depression risk was not significantly different from people without HS. Having more hospital stays for HS-related surgery was linked to higher risk, but researchers did not find a clear pattern of risk increasing with more surgeries.
At the start of the study, people with HS were more likely to have had depression or anxiety in the past, but during follow-up, their chances of it coming back were about the same as those without HS.
This study had several strengths, including a large number of participants, long follow-up and detailed registry data that made it possible to account for other health conditions and factors. It also looked at both depression and anxiety in the same group of patients and broke down the results by signs of disease severity.
The study had several limitations. Because the registry data were not collected for research, some patients may have been misclassified or had undiagnosed HS. Depression and anxiety were defined broadly, from mild to severe, making it difficult to measure the effect of illness severity.
Disease severity was based on treatments received, which may not match a patient’s actual condition and can be affected by doctor or patient choices. In addition, medication adherence wasn’t measured. HS cases treated only in primary care were also excluded, and the mostly White Danish population means the results may not apply to other groups.
The authors of this study stressed that clinicians should screen for depression and anxiety in all HS patients, regardless of disease severity, given the significant risk identified. They urged for further research to uncover other factors that may contribute to mental health challenges in this population.