Background: Depression exists in mild, moderate, and severe depressive attacks.Evidence suggests that depression is linked to anemia. Several studies have establisheda correlation between depression and anemia. In previous studies, a venous blood samplewas normally used to analyze the average value of hemoglobin and parameters oferythrocytes. The current study examined full blood count (FBC) in different populationsof erythrocytes in individuals with depression (DE) compared to a healthy control group(CON).

Material and Methods: All DE, n=24 were diagnosed with DSM-IV and ICD-10. CON,n=54 served as controls. A Percoll™ gradient was used to separate erythrocytes intodifferent density fractions. In all fractions, FBC, i.e., red blood cell count (RBC),hemoglobin concentration (Hb), mean corpuscular hemoglobin (MCH), mean bodyhemoglobin concentration (MCHC) and mean body volume (MCV) were analyzed usinga CELL-DYN 4000. As a comparison, a second blood sample was also taken, where themean values of FBC were analyzed.

Results: When the mean value of FBC was analyzed, no significant difference was foundbetween the groups. In contrast, when erythrocytes were separated by density, a lesseramount of Hb was found amongst the smaller erythrocytes, i.e. fractions nos. 8-17 (p <0.05). No significant difference was found when measuring MCH and MCHC in the samedensity fractions.

Conclusion: The current study provides evidence that smaller erythrocytes that weredivided by density have less hemoglobin. However, erythrocytes which were notseparated by density i.e. mean values of hemoglobin showed no difference between thegroups. For that reason, it may be of value to perform an extended analysis oferythrocytes and hemoglobin as a complement to the average value of hemoglobin. Thismay be of value when DE patients are investigated for anemia.