Correspondence (letter to the editor): Causes of Depression in Sarcoidosis

Many thanks for this great review article (1). I am a general practitioner who runs a sarcoidosis clinic, and as such I missed the psychosomatic aspect. This is relevant because almost all of my sarcoidosis patients experience depression. Little of relevance is to be found in the literature. An older article (2) from Göttingen offers the conclusion that sarcoidosis patients are “mostly in a chronic situation of conflict or overload” and that they can be “described as workaholic in some cases.” The study included very few patients, and participants had completed and returned an extremely comprehensive questionnaire. My conclusion is that it was particularly conscientious and helpful patients that were studied in this setting.

My own impression is that depression in sarcoidosis is based on four factors. Firstly, biochemistry: inflammation affects psychological and cognitive functions, as is the case in many autoimmune conditions and interferon therapy. Mediators of inflammation will cause depression quasi-physiologically. Secondly, the leaden fatigue hampers everyday coping and social contacts. Thirdly, sarcoidosis often develops at a young age and takes a chronic and burdensome course, and its treatment may trigger adverse effects—all of which cause worry and anxiety. Fourthly, even small doses of steroids can trigger depression or make it worse.

One further points: In my patients, I measure both vitamin D concentrations: 25-hydroxyvitamin D and 1.25-hydroxyvitamin D, and in the ratio of the two I see a parameter of activity that is often more sensitive than angiotensin-converting enzyme and the soluble interleukin-2 receptor. Furthermore, some sarcoidosis patients have evident vitamin D deficiency, and an indication for substitution exists.