Tobias Bracht1, Helge Horn2, Werner Strik2, Andrea Federspiel3, Susanne Schnell4, Oliver Höfle2, Katharina Stegmayer2, Roland Wiest5, Thomas Dierks3, Thomas J Müller2, Sebastian Walther2. 1. University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: bracht@puk.unibe.ch. 2. University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. 3. University Hospital of Psychiatry, Department of Psychiatric Neurophysiology, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. 4. Departments of Radiology and Biomedical Engineering, Northwestern University, Feinberg School of Medicine, 737 N. Michigan Ave Suite 1600, Chicago, IL 60611, USA. 5. Institute of Diagnostic and Interventional Neuroradiology, Inselspital, University of Bern, Freiburgstrasse 3010, Bern, Switzerland.
Abstract
BACKGROUND: The medial forebrain bundle (MFB) is a key structure of the reward system and connects the ventral tegmental area (VTA) with the nucleus accumbens (NAcc), the medial and lateral orbitofrontal cortex (mOFC, lOFC) and the dorsolateral prefrontal cortex (dlPFC). Previous diffusion tensor imaging (DTI) studies in major depressive disorder point to white matter alterations of regions which may be incorporated in the MFB. Therefore, it was the aim of our study to probe white matter integrity of the MFB using a DTI-based probabilistic fibre tracking approach. METHODS: 22 patients with major depressive disorder (MDD) (12 melancholic-MDD patients, 10 non-melancholic-MDD patients) and 21 healthy controls underwent DTI scans. We used a bilateral probabilistic fibre tracking approach to extract pathways between the VTA and NACC, mOFC, lOFC, dlPFC respectively. Mean fractional anisotropy (FA) values were used to compare structural connectivity between groups. RESULTS: Mean-FA did not differ between healthy controls and all MDD patients. Compared to healthy controls melancholic MDD-patients had reduced mean-FA in right VTA-lOFC and VTA-dlPFC connections. Furthermore, melancholic-MDD patients had lower mean-FA than non-melancholic MDD-patients in the right VTA-lOFC connection. Mean-FA of these pathways correlated negatively with depression scale rating scores. LIMITATIONS: Due to the small sample size and heterogeneous age group comparisons between melancholic and non-melancholic MDD-patients should be regarded as preliminary. CONCLUSIONS: Our results suggest that the melancholic subtype of MDD is characterized by white matter microstructure alterations of the MFB. White matter microstructure is associated with both depression severity and anhedonia.
BACKGROUND: The medial forebrain bundle (MFB) is a key structure of the reward system and connects the ventral tegmental area (VTA) with the nucleus accumbens (NAcc), the medial and lateral orbitofrontal cortex (mOFC, lOFC) and the dorsolateral prefrontal cortex (dlPFC). Previous diffusion tensor imaging (DTI) studies in major depressive disorder point to white matter alterations of regions which may be incorporated in the MFB. Therefore, it was the aim of our study to probe white matter integrity of the MFB using a DTI-based probabilistic fibre tracking approach. METHODS: 22 patients with major depressive disorder (MDD) (12 melancholic-MDDpatients, 10 non-melancholic-MDDpatients) and 21 healthy controls underwent DTI scans. We used a bilateral probabilistic fibre tracking approach to extract pathways between the VTA and NACC, mOFC, lOFC, dlPFC respectively. Mean fractional anisotropy (FA) values were used to compare structural connectivity between groups. RESULTS: Mean-FA did not differ between healthy controls and all MDDpatients. Compared to healthy controls melancholic MDD-patients had reduced mean-FA in right VTA-lOFC and VTA-dlPFC connections. Furthermore, melancholic-MDDpatients had lower mean-FA than non-melancholic MDD-patients in the right VTA-lOFC connection. Mean-FA of these pathways correlated negatively with depression scale rating scores. LIMITATIONS: Due to the small sample size and heterogeneous age group comparisons between melancholic and non-melancholic MDD-patients should be regarded as preliminary. CONCLUSIONS: Our results suggest that the melancholic subtype of MDD is characterized by white matter microstructure alterations of the MFB. White matter microstructure is associated with both depression severity and anhedonia.
Authors: Mina M Rizk; Harry Rubin-Falcone; John Keilp; Jeffrey M Miller; M Elizabeth Sublette; Ainsley Burke; Maria A Oquendo; Ahmed M Kamal; Mohamed A Abdelhameed; J John Mann Journal: J Affect Disord Date: 2017-06-30 Impact factor: 4.839
Authors: Gavin J B Elias; Aaron Loh; Dave Gwun; Aditya Pancholi; Alexandre Boutet; Clemens Neudorfer; Jürgen Germann; Andrew Namasivayam; Robert Gramer; Michelle Paff; Andres M Lozano Journal: Brain Date: 2021-04-12 Impact factor: 13.501