This cross-sectional study explores whether ocular features of keratoconjunctivitis sicca (KCS) or symptoms of dry eye disease are associated with depression in women with Sjögren syndrome (SS).
Study design
Researchers examined 3,514 participants from the Sjögren’s International Collaborative Clinical Alliance (SICCA), which is composed of 9 international clinical sites. Only females who met 1 of 5 criteria for SS were included in this analysis. Baseline questionnaires, laboratory workup and ocular examinations, including the Patient Health Questionnaire 9 (PHQ-9), were assessed to determine depression.
Outcomes
The authors demonstrated that dry eye and SS symptoms (e.g., eyes feeling dry, OR 1.82; mouth feeling dry, OR 2.13) were far more associated with depression than clinical findings such as staining scores. Women with SS had a lower odds of depression than those without SS, regardless of whether the women were symptomatic (OR 0.68) or asymptomatic (OR 0.59).
Limitations
The seemingly protective effect of SS against depression, while superficially a conundrum, may be explained by the reduced anxiety associated with having a known diagnosis versus bias stemming from questionnaire-based data.
A biological explanation may also exist, in that elevated SS titers could produce less depression-inducing inflammatory substances such as serum amyloid A.
Clinical significance
The authors provide important evidence to support the link between SS and depression. They present a much higher prevalence of depression than the general population, highlighting the importance of recognizing this link to improve quality of life.