Reduced Cortical Thicknesses of Adolescents with Bipolar Disorder and Relationship with Brain-derived Neurotrophic Factor

Scand J Child Adolesc Psychiatr Psychol. 2023 Jun 26;11(1):78-86. doi: 10.2478/sjcapp-2023-0008. eCollection 2023 Jan.

Abstract

Background: Cortical thickness (CT) and brain-derived neurotrophic factor (BDNF) were widely investigated in bipolar disorder (BD). Previous studies focused on the association between the volume of subcortical regions and neurotrophic factor levels.

Objective: In this study, we aimed to evaluate the association of the CT in youth with early-onset BD with BDNF levels as a potential peripheral marker of neuronal integrity.

Method: Twenty-three euthymic patients having a clinical diagnosis of BD and 17 healthy subjects as an age-matched control group with neuroimaging and blood BDNF levels were found eligible for CT measurement. A structural magnetic resonance scan (MRI) and timely blood samples were drawn.

Results: Youth with BD exhibited lower cortical thickness in caudal part of left (L) middle frontal gyrus, right (R) paracentral gyrus, triangular part of R inferior frontal gyrus, R pericalcarine region, R precentral gyrus, L precentral gyrus, R superior frontal gyrus and L superior frontal gyrus when compared to healthy controls. The effect sizes of these differences were moderate to large (d=0.67-0.98) There was a significant correlation between BDNF levels with caudal part of the R anterior cingulate gyrus (CPRACG) in adolescents with BD (r=0.49, p=0.023).

Conclusion: As a special region for mood regulation, the CT of the caudal part of the R anterior cingulate gyrus had a positive correlation with BDNF. Regarding the key role of CPRACG for affective regulation skills, our results should be replicated in future follow-up studies, investigating a predictive neuroimaging biomarker for the early-onset BD.

Keywords: Brain-derived neurotrophic factor; Cortical thickness; Early-onset bipolar disorder; Neurotrophic factors.

Grants and funding

This study was supported by the Dokuz Eylül University Foundation of Scientific Research Projects (BAP) and was partly supported by the Research Support Award 2008 of the International Society for Bipolar Disorders-affiliated Society for Bipolar Disorders-Turkey.