Frontal white matter anisotropy and symptom severity of late-life depression: a magnetic resonance diffusion tensor imaging study
- K Nobuhara1,
- G Okugawa1,
- T Sugimoto1,
- T Minami1,
- C Tamagaki1,
- K Takase1,
- Y Saito1,
- S Sawada2,
- T Kinoshita1
- 1Department of Neuropsychiatry, Kansai Medical University, Moriguchi, Japan
- 2Department of Radiology, Kansai Medical University, Moriguchi, Japan
- Correspondence to: Dr Kenji Nobuhara 10-15 Fumizono-cho Moriguchi City, 570-8506, Japan;
- Received 29 September 2004
- Accepted 8 April 2005
- Revised 7 April 2005
Objectives: To investigate the disruption of neural circuits in the frontal lobes and limbic structures in late-life depressed patients compared with healthy controls, and to examine the correlation between the degree of microstructural abnormalities of white matter and clinical symptom severity in late-life depression.
Methods: Thirteen patients with late-life depression and matched control subjects underwent diffusion tensor imaging. Fractional anisotropy (FA), an index of the integrity of white matter tracts, was determined in the white matter of frontal, temporal, and occipital brain regions and the corpus callosum.
Results: A significant reduction was found in white matter FA values of widespread regions of the frontal and temporal lobes of depressed patients. Also, there was some evidence suggesting that white matter FA values of the inferior frontal brain region are inversely related to severity of depression.
Conclusions: These results suggest the possible loss of integrity within frontal and temporal white matter fibre tracts and implicate the orbitofrontal circuit in symptom severity in late-life depression.
- AC/PC, anterior commissure/posterior commissure
- DTI, diffusion tensor imaging
- FA, fractional anisotropy
- HDRS, Hamilton Depression Rating Scale
- ROI, region of interest
This work was supported by a grant from the Ministry of Education, Science, and Culture of Japan (16591173).
Competing interests: none declared