1. Increased risk of depression in patients with cutaneous lupus erythematosus and systemic lupus erythematosus: a Danish nationwide cohort study 
Jeanette Halskou Hesselvig1, Alexander Egeberg1, Kristian Kofoed1, Gunnar Gislason2, Lene Dreyer3,4,5
1 Department of Dermatology and Allergy, Herlev and Gentofte University Hospital, Copenhagen, Denmark
2 Department of Cardiology, Herlev and Gentofte University Hospital, Copenhagen, Denmark
3 Department of Rheumatology, Herlev and Gentofte University Hospital, Copenhagen, Denmark
4 The Parker Institute, Bispebjerg and Frederiksberg Hospital, Frederiksberg, Denmark
5 Departments of Clinical Medicine and Rheumatology, Aalborg University and Aalborg University Hospital, Aalborg, Denmark
British Journal of Dermatology. DOI: /bjd.16831

2. Lead author: Jeanette Halskou Hesselvig

3. Introduction What’s already known?
Reported prevalences of depression in patients with systemic lupus erythematosus (SLE) range widely, while the prevalence of depression in cutaneous lupus erythematosus (CLE) remains severely understudied

4. Objective
To examine whether patients with SLE or CLE have increased risk of depression

5. Methods
A nationwide observational cohort study based on the Danish health registers
We included patients ≥18 years with a first-time diagnosis of SLE or CLE between 2000­­­–2015
We matched the cases (SLE or CLE) with general population in a 1:10 ratio

6. Methods
Analyses of risk for depression and antidepressant use were performed in Cox regression models
The analyses were adjusted for age, sex, socio- economic status, smoking, alcohol abuse, prior depression, and prior antidepressant use

7. Results
The study comprised 1,424 and 2,065 patients with CLE and SLE, respectively, matched with 34,890 people from the general population
We followed the patients with CLE and SLE for 8,103 and 15,270 person- years, respectively

8. Results
SLE and CLE were associated with a significantly increased risk of depression and antidepressant use (Table 2)
Table 2 Crude and adjusted hazard ratios for depression and antidepressant use in patients with lupus erythematosus compared with the general population
Table 2 Crude and adjusted hazard ratios for depression and antidepressant use in patients with lupus erythematosus compared with the general population

9. Results
Patients with SLE or CLE had an increased risk of severe depression compared with general population (Fig. 1)
Severe depression was defined as a hospitalization due to depression at a Department of Psychiatry or at a hospital in general
Department of psychiatry
Department of psychiatry

10. Discussion
We found a 2-fold increased risk of depression in patients with CLE or SLE compared with the the general population in Denmark
The risk of depression is of similar magnitude in CLE and SLE indicating that the involvement of the skin as well as the systemic involvement affects the overall risk of depression

11. Discussion
The cause for the increased risk of depression remains unclear
It can be a direct consequence of the disease as due to the systemic inflammation, or an indirect consequence as due to the psychological burden of having a chronic disease

12. Conclusions What does this study add?
In this nationwide cohort study patients with CLE or SLE had a 2-fold increased risk of depression compared with the general population in Denmark

13. Research Team
Jeanette Halskou Alexander Egeberg Kristian Kofoed Gunnar Gislason Lene Dreyer
Hesselvig

14. Call for correspondence
Why not join the debate on this article through our correspondence section?
Rapid responses should not exceed 350 words, four references and one figure
Further details can be found here