Brain-derived neurotrophic factor levels in newly diagnosed patients with bipolar disorder, their unaffected first-degree relatives and healthy controls

Abstract

Background Brain-derived neurotrophic factor (BDNF), which facilitates neuroplasticity and synaptogenesis, may be decreased in bipolar disorder, but has not been systematically investigated in people with newly diagnosed bipolar disorder and unaffected first-degree relatives. Aims To compare BDNF levels in patients with newly diagnosed bipolar disorder, their unaffected first-degree relatives and healthy controls. Method The study investigated plasma BDNF levels in patients (n = 371) with newly diagnosed bipolar disorder, their unaffected first-degree relatives (n = 98) and healthy controls (n = 200) using enzyme-linked immunosorbent assay. We further investigated associations between BDNF levels and illness-related variables and medication status. Results BDNF levels were found to be 22.0% (95% CI 1.107–1.343) higher in patients with bipolar disorder compared with healthy controls (P < 0.001) and 15.6% higher in unaffected first-degree relatives compared with healthy controls (95% CI 1.007–1.327, P = 0.04), when adjusting for age and gender. Further, BDNF levels were positively associated with duration of illness at a trend level (P = 0.05), age (P = 0.001) and use of anti-epileptic medication (P = 0.05). Conclusions These findings suggest that BDNF levels are not decreased in the early stages of bipolar disorder and in unaffected first-degree relatives contrasting with prior findings during later stages of the illness.

Is SARS-CoV-2 a Risk Factor of Bipolar Disorder?—A Narrative Review

“…However, some studies also indicated an increased level of BDNF among patients with newly diagnosed BD—up to 22% compared to the control group. It was also noted that the level of BDNF positively correlated with the duration of the disease, which is in contrast to the results of other studies [ 147 ], which showed that BDNF is reduced only in patients with advanced stage of BD, and its levels decline with the duration of the disease [ 148 ]. Lin et al (2016) also did not seem to confirm the reduction in BDNF in manic patients.…”

“…These results, however, are not consistent in all cases and there are studies that do not show a decrease in BDNF, or even its increase among patients who developed “long-COVID” [ 160 ]. The decrease in BDNF is also noticeable among patients with BD, although the opposite results can be found in this case as well [ 144 , 145 , 147 ]. Such a picture may correspond to the hypothesis that there is an overall decrease in BDNF during the course and progression of BD, but manic episodes may be triggered by a temporary and rapid increase in BDNF secretion [ 150 ].…”

Plasma BDNF and Cytokines Correlated with Protein Biomarkers for Bipolar II Disorder

“…In addition, we found a significantly positive correlation between levels of FARSB and BDNF in both patients and controls. A previous study reported decreased peripheral BDNF in BD in the later stage [19]; however, one recent study found that BDNF levels were increased in early-staged BD [35]. The study by Petersen et al [35] suggested that increased BDNF in patients with BD in the early stage of the illness compared to controls may be explained by ( 1) younger age of the study group as well as (2) in-time diagnosis and in-time treatment intervention.…”

“…A previous study reported decreased peripheral BDNF in BD in the later stage [19]; however, one recent study found that BDNF levels were increased in early-staged BD [35]. The study by Petersen et al [35] suggested that increased BDNF in patients with BD in the early stage of the illness compared to controls may be explained by ( 1) younger age of the study group as well as (2) in-time diagnosis and in-time treatment intervention. Another meta-analysis comprised of 3798 participants found that BDNF levels increased with illness duration of BD [36].…”

Investigation of Blood-Brain Barrier Disruption in an Animal Model of Mania Induced by d-Amphetamine

“…Speci cally, mood episodes include mania, hypomania, and alternating episodes of depression (Grande et al, 2016). Although no speci c biomarker has been identi ed, individuals with BD present with increased peripheral levels of in ammatory and oxidative stress markers accompanied by altered levels of neurotrophic factors (van den Ameele et al, 2020Ameele et al, , 2017Fernandes et al, 2011;Ghafouri-Fard et al, 2019;Kim et al, 2007;Petersen et al, 2021). Hence, BD is associated with a chronic low-grade in ammatory state, which seems to be coordinated with mood symptoms and cognitive de cits during the cour Bipolar disorder (BD) is a recurrent chronic and disabling disorder characterized by uctuations in mood, energy, and functioning (American Psychiatric Association, 2013).…”