title: Impaired frontothalamic circuitry in suicidal patients with depression revealed by diffusion tensor imaging at 3.0 T.
abstract: BACKGROUND
  The neurobiology of suicide is largely unknown. Studies of white matter tracts in patients with a history of suicidal behaviour have shown alteration in the left anterior limb of the internal capsule (ALIC). Our aim was to determine whether particular target fields of fibre projections through the ALIC are affected in depressed patients who recently attempted suicide.
  
  
  METHODS
  We studied patients with major depressive disorder (MDD) with and without a history of suicide attempts and healthy controls using diffusion tensor imaging (DTI) and deterministic tractography to generate fibre tract maps for each participant. Tract voxels were coded as being unique to the left ALIC. We compared the mean percentage of fibres projecting to relevant brain regions in the 3 groups using analysis of covariance.
  
  
  RESULTS
  We included 63 patients with MDD (23 with and 40 without a history of suicide attempts) and 46 controls in our study. Both groups of depressed patients had reduced fibre projections through the ALIC to the left medial frontal cortex, orbitofrontal cortex and thalamus. Those with a history of suicide attempts had greater abnormalities than those without suicide attempts in the left orbitofrontal cortex and thalamus.
  
  
  CONCLUSIONS
  Diffusion tensor imaging deterministic tracking is unable to distinguish between afferent and efferent pathways, limiting our ability to distinguish the directionality of altered fibre tracts.
  
  
  CONCLUSIONS
  Frontothalamic loops passing through the ALIC are abnormal in patients with depression and significantly more abnormal in depressed patients with a history of suicide attempts than in those without a history of suicide attempts. Abnormal projections to the orbitofrontal cortex and thalamus may disrupt affective and cognitive functions to confer a heightened vulnerability for suicidal behaviour.
authors.affiliation: Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Jia
authors.affiliation: Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Psychiatry, State Key Lab of Biotherapy, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Kuang
authors.affiliation: Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Qizhu
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Su
authors.initials: S
authors.lastname: Lui
authors.affiliation: Departments of Psychiatry and Pediatrics, University of Texas Southwestern, Dallas, Tex., USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Sweeney
authors.affiliation: Huaxi Magnetic Resonance Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Qiyong
authors.initials: Q
authors.lastname: Gong
mesh_terms: D000328:Adult; D003865:Major Depressive Disorder / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D020772:Internal Capsule / Q000473:pathology*; D008297:Male; D013406:Suicide, Attempted; D013788:Thalamus / Q000473:pathology*