People with unipolar depression and bipolar disorder may experience cognitive difficulties, even when they’re not currently depressed. In a study published in the journal European Neuropsychopharmacology in 2016, researchers led by Caroline Vintergaard Ott determined that treatment with the hormone erythropoietin (EPO) may help. EPO is produced in the kidney and increases the production of hemoglobin and red cells.
Seventy-nine participants with unipolar or bipolar disorder were randomized to receive infusions of either EPO or a saline solution once a week for eight weeks. By the end of the study, those who received EPO showed significant improvements in the speed of their complex cognitive processing compared to those who received saline. EPO is known to induce the production of red blood cells. The improvements in processing speed lasted for at least another six weeks after red blood cell production would have normalized.
Those participants who received EPO not only had improved scores on tests of processing speed, they also reported fewer cognitive complaints. The EPO treatment was most likely to be effective in participants who had more impaired cognition at the beginning of the study.
In previous research by the same research group presented by Kamilla W. Miskowiak at the 2014 meeting of the International Society of Bipolar Disorders, EPO also improved sustained attention and recognition of happy faces.
Bipolar disorder is associated with cognitive dysfunction, and no definitive treatment has yet been found to reverse these problems with memory and attention. A new study by Kamilla W. Miskowiak presented at the 2014 meeting of the International Society of Bipolar Disorders explored the use of erythropoietin, a hormone that induces the production of red blood cells, as a treatment for cognitive dysfunction in bipolar disorder.
Participants in the double-blind study were randomized to receive either eight weekly erythropoietin infusions (40,000 IU) or eight weekly saline infusions. While there was only a trend toward improvement in verbal memory, there were other statistically significant outcomes: erythropoietin improved sustained attention, recognition of happy faces, and speed of complex information processing across learning, attention, and executive function. These outcomes were not related to changes in reaction time or mood, and lasted as long as six weeks after the eighth erythropoietin infusion, by which time red blood cell production had normalized.