Decreased levels of serum brain-derived neurotrophic factor in both depressed and euthymic patients with unipolar depression and in euthymic patients with bipolar I and II disorders.

Abstract

OBJECTIVES:

Brain-derived neurotrophic factor (BDNF) has been proposed as a candidate molecule in the pathophysiology of major depressive disorder (MDD) and bipolar disorders (BD). Reduced levels of peripheral BDNF have been found in drug-free MDD patients, in drug-treated depressed or manic patients with BD type I (BD-I), but not in drug-treated euthymic BD-I individuals. No study has been done in patients with BD type II (BD-II). Moreover, the influence of Axis I psychiatric comorbidity on circulating BDNF in affective patients has never been evaluated. Therefore, in the present study, we aimed: (i) to confirm previous findings on peripheral BDNF in MDD and BD-I patients; (ii) to assess whether changes in circulating BDNF occur also in patients with BD-II; and (iii) to exclude the possibility that comorbid psychiatric disorders exerted an effect on BDNF levels in affective patients.

METHODS:

We measured serum BDNF concentrations by an enzyme-linked immunosorbent assay method in 85 subjects, including 24 euthymic patients with unipolar depression (UD), 17 euthymic patients with BD-I, 11 euthymic patients with BD-II, 11 UD patients with a current major depressive episode and 22 drug-free healthy controls. At the time of the study, 15 patients were drug-treated; the remaining ones were drug-free for at least four weeks.

RESULTS:

Compared to healthy controls, serum BDNF concentrations were significantly reduced in all the patient groups (F(4,80) = 3.840, p = 0.006) with no significant difference among them. Drug treatments and comorbid psychiatric disorders had no effect on lowered circulating BDNF levels in affective patients.

CONCLUSIONS:

Present results confirm previous independent findings of reduced circulating BDNF in patients with MDD and report, for the first time, decreased serum BDNF levels in euthymic patients with UD, BD-I and BD-II, independently from drug treatment status and concomitant Axis I psychiatric disorders.

• Authors: P Monteleone, C Serritella, V Martiadis, M Maj
• Journal: Bipolar disorders (Bipolar Disord) Vol. 10 Issue 1 Pg. 95-100 (Feb 2008) ISSN: 1398-5647 [Print] Denmark
• PMID: 18199246 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Brain-Derived Neurotrophic Factor

Topics

• Adult
• Bipolar Disorder (blood, classification, complications)
• Brain-Derived Neurotrophic Factor (blood)
• Depression (blood, complications)
• Female
• Humans
• Male
• Middle Aged
• Outpatients