Inclusion Criteria:

   1. Must meet DSM-IV criteria for Major Depressive Disorder

   2. HAM-D score >18 on a 21-item assessment at eligibility

   3. On at least an adequate dose of fluoxetine (40 mg/day), paroxetine (40 mg/day)
   paroxetine CR (50mg), sertraline (150 mg/day), citalopram (40 mg/day), escitalopram
   (20 mg/day), venlafaxine (150 mg/day), mirtazapine (30 mg/day), or duloxetine (60
   mg/day) for at least 6 weeks (monotherapy).

   4. 20-55 years of age

Exclusion Criteria:

   1. Substance abuse in the past 6 months

   2. ECT in the past 6 months

   3. On a MAOI, tricyclic antidepressant, lithium, an antipsychotic, thyroid augmentation,
   2 antidepressants simultaneously or lamotrigine

   4. History of any psychosis including psychotic depression

   5. History of Bipolar I, Bipolar II, or Bipolar NOS illness, or concurrent symptoms of
   mania or hypomania that do not meet the criteria for any bipolar disorder

   6. History of compulsive gambling

   7. Pregnant females or females of childbearing years not using adequate birth control in
   the opinion of the investigators

   8. Known sensitivity to Pramipexole

   9. Significant suicide risk in the opinion of the investigators

10. Significant medical conditions that would preclude safe participation in the study in
   the opinion of the investigators

11. Psychoactive drugs other than one of the antidepressants listed on Inclusion criteria
   #4. (A non-barbiturate sedative or hypnotic or benzodiazepine such as trazodone
   50mg/day, zolpidem 10mg/day, lorazepam 3mg/day or clonazepam 2mg/day will be allowed
   if it has been in use for at least 1 month prior to the baseline visit.)

12. Significant abnormalities are observed in screening laboratory evaluation.