Common Tests Or Labs To Diagnose Depression

The first step in evaluating a patients depression level (hyperlink “DEPRESSION” to main depression overview page) is a thorough history and discussion including any new symptoms, distress, new life changes, lifestyle changes, etc. and a complete physical examination.


Type of Test

What is Tested?

Normal Range

Blood Test Thyroid function and glucose levels TSH= .5-6 uU/mlT4 = 4.6-12 ug/dl

T3 = 80-180 ng/dl

RAIU= 10-30%

TBG= 12-20 ug/dl

Glucose= 70-100

Complete blood count (CBC) Hemoglobin, hemocrit and white and red blood cell count HemoglobinMen: 13-18 gm/dL

Women: 12-17 gm/dL 


Men: 45-52

Women: 37-48

WBC= 4300-10,800 cmm

RBC= 4.2-5.9 million cells/cubic millimeter

Computed Tomography

(CT Scan)

Brain Scan uses many x-ray viewsNormal would show no masses, no constriction of cerebral blood flow, no obstruction of sinuses or fluid sacs
Magnetic Resonance Imaging (MRI) Brain No breakage in neural synapses, no masses, no obstruction, no constriction of blood vessels



Torso A normal EKG is a pattern with a P wave followed by a QRS wave, with an interval rest period whereupon the pattern recurs.P wave rate = 60-100 bpm

P height < 2.5 mm in lead II

P width < .11 in lead II

PR interval= .12-.20 s

QRS complex < .12 s

Normal ST segment= no elevation or depression



Head 8 Hz most wave frequencies when awake. Some waves are recognized by shape, scalp location and distribution as well as symmetry. There are certain patterns considered normal for both awake and asleep.Epileptics and various nerve disorders demonstrate an abnormal pattern or wave frequency of 7 or less.


There are several well-respected cognitive tests available to screen for depression and some are geared to a specific age group.


Age 7-17 years - Children’s Depression Inventory (CDI)

  • Seeks input from parents and teachers about the child
  • Input reflects family and home situations
  • Input reflects academics and school interactions
  • Questionnaire of 27 questions with 3 descriptive statements each reflecting feelings within a 2-week interval.
  • Developed by Dr. Maria Kovacs at University of Pittsburgh


Age 14-80 - Beck Depression Inventory (BDI-II)

  • Questionnaire with 21 multiple-choice questions
  • Depression symptoms are measured in each item
  • Extent of depression is determined by score tally
  • Designed by Dr. Neil Beck at University of Pennsylvania


Adults - Hamilton Depression Rating Scale (HAM-D)

  • Oral examination of 21 questions as opposed to the others
  • Gold standard for rating efficacy of antidepressants (according to March/April 2003 issue of “Psychotherapy and Psychosomatics”)
  • Devised by Dr. Max Hamilton at University of Leeds


Adults - Zung Self-Rating Depression Scale (ZDS)

  • Questionnaire of 20 questions and 4 choice
  • Extent of depression measured by score tally
  • Devised by Dr. William W. K. Zung at Duke University


Elderly - Geriatric Depression Scale (GDS)

  • 30-item Yes/No questionnaire
  • Targets seniors both ailing, healthy, or cognitively impaired
  • Designed by Dr. Joseph Yesavage at Stanford University


Written by Barbara Hales, MD