title: Frequency-dependent changes in amplitude of low-frequency oscillations in depression: A resting-state fMRI study.
abstract: OBJECTIVE
  We conducted this fMRI study to examine whether the alterations in amplitudes of low-frequency oscillation (LFO) of major depressive disorder (MDD) patients were frequency dependent.
  
  
  METHODS
  The LFO amplitudes (as indexed by amplitude of low-frequency fluctuation [ALFF] and fractional ALFF [fALFF]) within 4 narrowly-defined frequency bands (slow-5: 0.01-0.027Hz, slow-4: 0.027-0.073Hz, slow-3: 0.073-0.198Hz, and slow-2: 0.198-0.25Hz) were computed using resting-state fMRI data of 35 MDD patients and 32 healthy subjects. Repeated-measures analysis of variance (ANOVA) was performed on ALFF and fALFF both within the low frequency bands of slow-4 and slow-5 and within all of the four bands.
  
  
  RESULTS
  We observed significant main effects of group and frequency on ALFF and fALFF in widely distributed brain regions. Importantly, significant group and frequency interaction effects were observed in the ventromedial prefrontal cortex, inferior frontal gyrus, precentral gyrus, in a left-sided fashion, the bilateral posterior cingulate and precuneus, during ANOVA both within slow-4 and slow-5 bands and within all the frequency bands.
  
  
  CONCLUSIONS
  The results suggest that the alterations of LFO amplitudes in specific brain regions in MDD patients could be more sensitively detected in the slow-5 rather than the slow-4 bands. The findings may provide guidance for the frequency choice of future resting-state fMRI studies of MDD.
authors.affiliation: Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), Bejing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), Bejing, China.
authors.forename: Qingmei
authors.initials: Q
authors.lastname: Kong
authors.affiliation: Department of Radiology, 306 Hospital of People's Liberation Army, Beijing, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Li
authors.affiliation: Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), Bejing, China.
authors.forename: Yunai
authors.initials: Y
authors.lastname: Su
authors.affiliation: Department of Radiology, 306 Hospital of People's Liberation Army, Beijing, China.
authors.forename: Yawei
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Mood Disorders Center, Beijing Anding Hospital, Capital Medical University, Beijing, China.
authors.forename: Qinge
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), Bejing, China.
authors.forename: Wenji
authors.initials: W
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China; Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China. Electronic address: mxia@mail.bnu.edu.cn.
authors.forename: Mingrui
authors.initials: M
authors.lastname: Xia
authors.affiliation: Mood Disorders Center, Beijing Anding Hospital, Capital Medical University, Beijing, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Radiology, 306 Hospital of People's Liberation Army, Beijing, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Jin
authors.affiliation: Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), Bejing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
authors.affiliation: Peking University Sixth Hospital (Institute of Mental Health), National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), Bejing, China. Electronic address: si.tian-mei@163.com.
authors.forename: Tianmei
authors.initials: T
authors.lastname: Si
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D003865:Major Depressive Disorder / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D055815:Young Adult
keywords: Frequency dependence; Low-frequency oscillation; Major depressive disorder; Resting state; fMRI