Y Yalçın Arslan, N Yalin, A Ozerdem, D Cimrin, Z Tunca

Dokuz Eylul University Faculty of Medicine, Department of Adult Psychiatry, Izmir, Turkey

Objective: Patients with depression have consistently been found to have lower levels of folic acid (FA) than normal population or non-depressed psychiatric patients (Morris et al. 2008). Data on FA status in bipolar depression is scarce.

Methods: In this retrospective cross-sectional study, serum FA lev- els of 260 adult psychiatric in-patients with either DSM-IV bipolar depression (n = 57) or unipolar depression (n = 203) were com- pared to that of patients admitted to the dermatology outpatient clinic within a two year period (n = 456). Medical and psychiatric information and serum FA levels of patients were provided from the medical records and laboratory database of the Dokuz Eylul University Hospital respectively. Controls had no medical record for any psychiatric axis I disorder. For psychiatric inpatients, serum FA levels at the time of hospital admission, for control indi- viduals, first FA values of the two year period were included in the analysis. Statistical analysis was done using SPSS 15.0 (ANOVA, post hoc Bonferonni, after log transformation of values, and Spearman correlation test).

Results: The mean serum FA levels (± SD) were lower in both uni- polar (7.50 ± 4.11 ng/mL) and bipolar (7.41 ± 4.56 ng/mL) depression than controls (8.67 ±  4.28 ng/mL) (p < 0.000 and p = 0.015 respectively). The mean FA levels did not differ between the two patient groups. Age was positively correlated with serum FA levels in unipolar depression and control individuals (r = 0.152, p = 0.031 and r = 0.126, p = 0.007 respectively), but not in patients with bipolar depression (p = 0.236). Serum FA levels were not correlated with the duration of index episode, number of lifetime depressive episodes or baseline Hamilton Depression Scale scores in either depression type. Although FA levels were lower in males of the control group, there was no gender difference with regard to FA levels in either mood disorder.

Discussion: Decrease in serum FA levels is equally important in both bipolar and unipolar depression.

Keywords: folic acid, bipolar depression, unipolar depression

Bipolar Disorders © 2013 John Wiley & Sons A/S, Bipolar Disorders, 15 (Suppl. 1) 53–103