[Factors interfering with the dexamethasone suppression test]

Area of Science:

• Endocrinology
• Psychiatry
• Clinical Chemistry

Context:

• The dexamethasone suppression test (DST) is a crucial diagnostic tool.
• Accurate interpretation of DST results is vital in endocrinology and psychiatry.
• Several factors can interfere with DST accuracy.

Purpose:

• To elucidate variables affecting dexamethasone suppression test interpretation.
• To identify common causes of false-positive and false-negative DST results.

Summary:

• False-positive DST results can stem from physiological stress, weight loss, alcohol withdrawal, and medications like diphenylhydantoin, phenobarbital, rifampicin, carbamazepine, and lithium.
• Therapies with spironolactone, naloxone, alpha-1-mimetic agents, and estrogen may elevate plasma cortisol.
• False-negative DST results are observed in liver disease and with high-dose benzodiazepines, indomethacin, methadone, and ketoconazole.

Impact:

• Improved understanding of DST limitations.
• Enhanced diagnostic accuracy in endocrine and psychiatric disorders.
• Guidance for clinicians on interpreting DST results in the presence of confounding factors.