Increased BDNF Levels in Long-term Bipolar Disorder Patients

Abstract

The present study suggests that long-term BD patients exhibit increased circulating levels of BDNF.

Peripheral blood brain-derived neurotrophic factor in bipolar disorder: a comprehensive systematic review and meta-analysis

“…Thirtyfive studies, comprising a total of 2238 bipolar disorder patients and 1560 healthy control subjects, were eligible for review and included in the meta-analysis with a minimum of one pair-wise comparison each. [11][12][13][19][20][21]26, Exclusion of full 63 text articles and reports were based on (a) data on BDNF levels were unavailable, [66][67][68] (b) patients not suffering from bipolar disorder, [69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84] (c) the study not evaluating peripheral BDNF levels, (d) the study being a review or a comment, [107][108][109][110][111][112][113][114][115][116][117][118][119] (e) the study not comparing states or comparing bipolar patients with healthy control subjects [120][121][122] and/or (f) the study investigated treatment of experimental nature 123,124 and (g) the study presenting duplicate data presented in an included article. …”

“…Thirty-two studies were included in the meta-analysis of BDNF differences between bipolar disorder patients in various affective states and healthy control subjects. 11,13,19,20,26,[38][39][40][41][42] Ten studies provided data for comparisons between affective states in bipolar disorder patients, 12,19,20,26,38,41,42,46,48,65 of which two studies 12,26 included within-subject comparisons between a manic and euthymic state and one study 26 included withinsubjects comparisons between a depressed and euthymic state and a depressed and manic state (Supplementary Table 2-4S). Seven studies investigated changes in BDNF levels before and after treatment of an acute affective episode, 12,21,43,46,47,57,64 with follow-up periods ranging from 4 to 52 weeks.…”

“…41,42,44,45,48,49,64 Fifteen studies investigated plasma BDNF levels and twenty studies investigated serum BDNF levels. Ten studies reported the time of day blood samples were obtained, 12,19,21,26,39,45,52,53,56,61 ranging from 0800 to 1700 h. Six studies reported obtaining blood samples in a fasting state, 21,26,53,56,61,62 with the remaining studies providing no information regarding fasting state. Blinding of laboratory staff to the clinical state of participants was reported in eight studies.…”

“…Importantly, recent investigations have yielded substantial variation in outcomes between studies. 19,20 None of previous reviews have compared BDNF levels between affective states directly, relying on indirect evidence and did not evaluate the effect of medication in group-wise comparisons. More importantly, the incomplete matching between groups and the inherent risk of confounding related to several variables known to affect BDNF levels, such as body mass index (BMI), 21 exercise, 22 smoking and alcohol use, 23 was not addressed in a critical evaluation of the evidence and conclusions.…”

Neurotrophic factors in tension-type headache

“…Patients with TTH had more anxiety and depressive symptoms than controls. NF levels have been previously correlated with depression and anxiety disorders 16,17,18,19,20 . Despite this, there were no significant correlations among NF levels and anxiety and depression scores, and TTH patients with moderate anxiety and depression scores had not altered NF levels.…”