White matter pathway organization of the reward system is related to positive and negative symptoms in schizophrenia.
The reward system in schizophrenia has been linked to the emergence of delusions on the one hand and to negative symptoms such as affective flattening on the other hand. Previous Diffusion Tensor Imaging (DTI) studies reported white matter microstructure alterations of regions related to the reward system. The present study aimed at extending these findings by specifically investigating connection pathways of the reward system in schizophrenia. Therefore, 24 patients with schizophrenia and 22 healthy controls matched for age and gender underwent DTI-scans. Using a probabilistic fiber tracking approach we bilaterally extracted pathways connecting the ventral tegmental area (VTA) with the nucleus accumbens (NAcc), the medial and lateral orbitofrontal cortices (mOFC, lOFC), the dorsolateral prefrontal cortex (dlPFC) and the amygdala; as well as pathways connecting NAcc with mOFC, lOFC, dlPFC and amygdala resulting in a total of 18 connections. Probability indices forming part of a bundle of interest (PIBI) were compared between groups using independent t-tests. In 6 connection pathways PIBI-values were increased in schizophrenia. In 3 of these pathways the spatial extension of connection pathways was decreased. In schizophrenia patients, there was a negative correlation of PIBI-values and PANSS negative scores in the left VTA-amygdala and in the left NAcc-mOFC connection. A sum score of delusions and hallucinations correlated positively with PIBI-values of the left amygdala-NAcc connection. Structural organization of specific segments of white matter pathways of the reward system in schizophrenia may contribute to the emergence of delusions and negative symptoms in schizophrenia.
University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: bracht@puk.unibe.ch.
Tobias
T
Bracht
University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: horn@puk.unibe.ch.
Helge
H
Horn
University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: strik@puk.unibe.ch.
Werner
W
Strik
University Hospital of Psychiatry, Department of Psychiatric Neurophysiology, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: Federspiel@puk.unibe.ch.
Andrea
A
Federspiel
University Hospital of Psychiatry, Department of Psychiatric Neurophysiology, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: razavi@puk.unibe.ch.
Nadja
N
Razavi
University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: stegmayer@puk.unibe.ch.
Katharina
K
Stegmayer
Institute of Diagnostic and Interventional Neuroradiology, Inselspital, University of Bern, Freiburgstrasse, 3010 Bern, Switzerland. Electronic address: roland.wiest@insel.ch.
Roland
R
Wiest
University Hospital of Psychiatry, Department of Psychiatric Neurophysiology, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: Dierks@puk.unibe.ch.
Thomas
T
Dierks
University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: Mueller@puk.unibe.ch.
Thomas J
TJ
Müller
University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. Electronic address: walther@puk.unibe.ch.
Sebastian
S
Walther
D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009434:Neural Pathways / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology*; D013223:Statistics as Topic; D055815:Young Adult
Delusions; Diffusion Tensor Imaging; Fiber tracking; Hallucinations; Salience system