Relationship between serum BDNF levels and cognitive functions, cortisol levels in depressive disorder?

Abstract

Objective: The objective of this study was to examine the relationship between the serum BDNF levels in depressive disorder patients and cognitive functions along with cortisol levels.

Methods: Thirty patients meeting the DSM-IV criteria for major depressive disorder were recruited for this study. Patients had not used any antidepressants. The severity of depression was assessed by the Hamilton Rating of Depression Scale (HAM-D17). Serum BDNF levels were determined by using ELISA. Neuropsychological evaluation included; Digit Span Test, Stroop Test, Verbal Memory Processing Test, and Weschler-Visual Memory.

Results: HAM-D17 scores were 17.09 +/- 4.96 in patients. Serum BDNF levels were established to be 1453.42 +/- 144.51 pg/mL, and mean serum morning cortisol level was established as 11.54 +/- 4.57 mu g/dL. No relationship was determined between the HAM-D17 scores and BDNF levels. The serum BDNF levels were not correlated with cortisol levels, and neuropsychological tests scores. Serum cortisol levels and Stroop test time differences were established to be positively correlated (rs=0.396 p=0.017). Serum cortisol levels were not correlated with other neuropsychogical tests.

Conclusion: No relationship was determined between the BDNF levels and attention and memory performances for patients with depression. It was determined that elevated morning baseline cortisol levels affected attention negatively. There was no correlation between serum BDNF levels and morning cortisol levels.