Brain-derived neurotrophic factor (BDNF) and its precursor proBDNF as diagnostic biomarkers for major depressive disorder and bipolar disorder

Excerpt

Major depressive disorder (MDD) and bipolar disorder (BD) are the most common adult-onset mood disorders. They are two etiologically related, but clinically distinct psychiatric illnesses. Their shared clinical features result in high rates of misdiagnosis, due to lack of differentiating biomarkers between the disorders. More frequently, BD is misdiagnosed as MDD, because of their overlapping symptomology, the often later onset of mania, and the frequent occurrence of depressive episodes in BD patients. Misdiagnosis is also high when BD patients present symptoms indicative of a clinically significant depressive episode, but are premorbid for manic symptoms, or previous manic states have not been recognized. Incorrect treatment of BD with antidepressant monotherapy increases the risk of antidepressant-induced mania and “cycle acceleration” (an increased frequency of episodes), both of which can have detrimental effects on disease prognosis in these patients. Therefore, the development of specific biomarkers for these disorders would be invaluable for establishing the correct diagnosis and treatment of MDD and BD [1]. …