Dexamethasone Suppression Test


  • EPIC Code:
  • LAB2287
  • Soft Test Code:
  • DST
Alternate Names
  • Dexamethasone Suppresion for Depression
  • DST
Included Tests

Baseline Cortisol; 4pm Cortisol; 11pm Cortisol

Specimen Collection & Preparation

Patient Preparation

 Patient should discontinue taking Biotin, Vitamin B7, or Vitamin H 48 hours before getting blood drawn.

Specimen Requirements

1.0 mL Serum in a SST Gold Top Tube

Alternate Specimen

1.0 mL Serum from a Red Top Tube in a Plastic Vial


48 hours Refrigerated

24 hours unspun

Collection Instructions

Depression Method
1. Request a baseline Cortisol to be drawn before dosage is given.
2.  A dose of 1 mg of Dexamethasone is to be given to the patient at 11:00 P.M.
3. Request a 4:00 P.M. and 11:00 P.M. Cortisol to be drawn the next day. Minor variations from these time (+) or (-) one hour, will not affect the performance of the test.

Minimum Volume

Neonatal Volumne

Clinical Interpretation

Reference Range:

Refer to Interpretive Results

Test Comments:

 Patients taking vitamin supplements containing high doses of biotin (>5 mg/day) may have falsely increased test results generated.

  • Chemiluminescence (CL)


Two methods are acceptable for Dexamethasone Suppression Testing. 
    The first one is used primarily as a screening test for Cushing’s Syndrome (Test Code DSTC1)
    The second is used on psychiatric patients to diagnose depression.(Test Code DST)

Production Schedule

Sites Performed
  • Parkview Regional Medical Center
  • Chemistry

Coding & Compliance

CPT Coding

82533 x 3