Adjunctive Allogeneic Mesenchymal Stem Cells for Treatment-resistant Bipolar Depression

Inclusion criteria: 1. Diagnosis of DSM-IV-TR of Bipolar I or Bipolar II disorder as verified by the semi-structured diagnostic interviews SCID. The diagnosis may be supported by information from significant others, and from hospital records. 2. Age: 18-65 years 3. Severity: meet DSM-IV-TR criteria of depressive episode and MADRS of 25 or above 4. Treatment resistance: None response to two trials (during lifetime) with mood stabilizers with proven efficacy in bipolar depression (lithium, lamotrigine, quetiapine, olanzapine) and/or antidepressants. a A trial is defined as at least 6 weeks in adequate or tolerated dose as reported by the patient, or patients that have been unable to comply with 6 weeks trials of mood stabilizer or an antidepressant. b None response: Less than 50% reduction in MADRS values or still meet DSM-IV-TR criteria of depressive episode 5. CRP concentration greater than 5 mg/L 6. Female subjects whom are not pregnant, not breastfeeding, and not planning on becoming pregnant during the study. Female patients of childbearing potential must be using a reliable method of contraception. 7. Patient competent to give informed consent according to the judgment of the clinician 8. Written informed consent 9. Patient sufficiently fluent in English language to ensure valid responses to psychometric testing (needed for validated neurocognitive outcomes testing) Exclusion criteria: 1. MSCs transplant within the last six months 2. Inability to comply with study protocol 3. Patient at high suicidal risk according to clinicians' judgement 4. History of previous brain injury; neurologic impairment and/or deficit; seizure disorder requiring anti-convulsant therapy; renal disease or altered renal function as defined by serum creatinine 2x ULN at admission; hepatic disease or altered liver function as defined by SGPT \> 2 x ULN (non-contusion related), and/or T. Bilirubin 1.5 x ULN at admission; immunosuppression as defined by WBC\<3,000 cells/ml at admission; HIV, splenectomy or cancer 5. Unstable serious medical conditions, including clinically relevant laboratory abnormalities. Conditions that affect neuropsychological assessment such as Parkinson's Disease, Multiple sclerosis, stroke, alcohol and substance abuse or dependence (according to SCID or DSM-IV-TR). Other serious medical illness that is not adequately controlled and, in the investigator's opinion, would not permit the subject to be managed according to the protocol. 6. Hemodynamic instability at the time of MSCs infusion. 7. Positive pregnancy test (at screening or baseline visits).