A Case-Control Study of Corticosteroid Exposure as a Risk Factor for Clinically-Diagnosed Depressive Disorders in a Hospitalized Population

OBJECTIVE: Depressive symptoms may be a side effect of exogenous corticosteroids. However, the literature does not confirm that corticosteroid exposure is associated with the occurrence of depressive disorders. The objective of this study was to determine whether or not corticosteroid exposures are associated with clinical diagnoses of depressive disorders in hospitalized patients. METHOD: The study used a case-control design. Cases and 2 control groups were selected from a health records case summary database maintained at the Calgary General Hospital. Additional data were collected by chart review. RESULTS: The analysis reproduced associations between depressive diagnoses and several psychosocial and biological risk factors. However, the data did not suggest that corticosteroids were associated with an elevated risk of depressive diagnoses. In fact, odds ratios for corticosteroid exposure were less than 1, consistent with a protective effect. CONCLUSIONS: Although corticosteroids may produce depressive symptoms as a side effect, corticosteroid exposures are not associated with an elevated risk of clinically diagnosed depressive disorders in hospitalized patients. There are several possible explanations for this. Depressive syndromes associated with corticosteroid exposure may not clinically resemble depressive disorders, and may not warrant a diagnosis of a depressive disorder. Alternatively, clinicians may not identify and formally diagnose depressive disorders caused by corticosteroids.