[Pseudo-Cushing syndrome. Physiopathologic aspects and differential diagnosis]

Pseudo-Cushing Syndromes (PCS) are a heterogeneous group of disorders, including alcoholism and depression, that share many of the clinical and biochemical features of Cushing's Syndrome (CS). It has been suggested that hypercortisolism of PCS may be the result of increased hypothalamic corticotropin-releasing hormone secretion in the context of a hypothalamic-pituitary-adrenal axis that is otherwise normally constituted. The substantial overlap in clinical features and daily urinary free cortisol levels between several patients with CS and those with PCS can make the differential diagnosis difficult. The most accurate tests in the distinction of CS from alcohol-induced PCS are dexamethasone-CRH and a midnight serum cortisol measurement. In depressed patients, the insulin tolerance test may be useful, although some overlap may exist. This brief review summarises the principal pathophysiological events of PCS and provides a useful strategy for differential diagnosis.