Effects of erythropoietin on memory-relevant neurocircuitry activity and recall in mood disorders.

Journal article

Objective

Erythropoietin (EPO) improves verbal memory and reverses sub-field hippocampal volume loss across depression and bipolar disorder. This study aimed to investigate with functional magnetic resonance imaging (fMRI) whether these effects were accompanied by functional changes in memory-relevant neuro-circuits in this cohort.

Method

Eighty-four patients with treatment-resistant unipolar depression who were moderately depressed or bipolar disorder in remission were randomized to eight weekly erythropoietin (40,000 IU) or saline infusions in a double-blind, parallel-group design. Participants underwent whole-brain fMRI at 3T, mood ratings and blood tests at baseline and week 14. During fMRI, participants performed a picture encoding task followed by post-scan recall.

Results

Sixty-two patients had complete data (EPO: N=32, saline: N=30). EPO improved picture recall and increased encoding-related activity in dorsolateral prefrontal cortex (dlPFC) and temporo-parietal regions, but not in hippocampus. Recall correlated with activity in the identified dlPFC and temporo-parietal regions at baseline, and change in recall correlated with activity change in these regions from baseline to follow-up across the entire cohort. The effects of EPO were not correlated with change in mood, red blood cells, blood pressure or medication.

Conclusion

The findings highlight enhanced encoding-related dlPFC and temporo-parietal activity as key neuronal underpinnings of EPO-associated memory improvement.

Authors: Miskowiak, K; Macoveanu, J; Vinberg, M; Assentoft, E; Randers, L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Acta Psychiatrica Scandinavica
• Volume: 134
• Issue: 3
• Pages: 249-259
• Publication date: 2016-06-01
• Acceptance date: 2016-05-09
• DOI: 10.1111/acps.12597
• EISSN: 1600-0447
• ISSN: 0001-690X
• Pmid: 27259062
• Language: English
• Keywords: cognition disorders; randomized controlled trial; functional neuroimaging; bipolar disorder