title: Baseline working memory activation deficits in dimensional anxious depression as detected by magnetoencephalography.
abstract: OBJECTIVE
  Anxiety often co-occurs with major depressive disorder (MDD). This preliminary study sought to ascertain the extent to which anxious depression drives group neurobiological differences between patients with MDD and healthy volunteers (HVs).
  
  
  METHODS
  Magnetoencephalography beta-band frequency was used to compare differences in brain response during the N-back working memory task between 30 medication-free patients with treatment-resistant MDD (anxious depression=18; nonanxious depression=12) and 28 HVs.
  
  
  RESULTS
  Compared to HVs, patients with anxious depression had significantly reduced desynchronisation (less activation) in the left precuneus, right cuneus, and left insula extending into the inferior and middle frontal cortex during the 2-back condition compared with the 1-back condition of the N-back working memory task--indicating less activation of these neural networks in patients with anxious depression during the condition with the highest level of task demands. No other significant group differences were found during the working memory conditions.
  
  
  CONCLUSIONS
  This preliminary study suggests that a subset of patients--those with anxious depression--may be driving observed group differences between patients with MDD and HVs. Further neurobiological studies and replication experiments are necessary to determine the extent to which this subgroup has preferentially influenced our understanding of the underlying neurobiology of depression.
authors.affiliation: 1Department of Psychiatry,Massachusetts General Hospital,Boston,MA,USA.
authors.forename: Dawn F
authors.initials: DF
authors.lastname: Ionescu
authors.affiliation: 3Experimental Therapeutics & Pathophysiology Branch,Intramural Research Program,National Institute of Mental Health,National Institutes of Health,Bethesda,MD,USA.
authors.forename: Allison C
authors.initials: AC
authors.lastname: Nugent
authors.affiliation: 3Experimental Therapeutics & Pathophysiology Branch,Intramural Research Program,National Institute of Mental Health,National Institutes of Health,Bethesda,MD,USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Luckenbaugh
authors.affiliation: 3Experimental Therapeutics & Pathophysiology Branch,Intramural Research Program,National Institute of Mental Health,National Institutes of Health,Bethesda,MD,USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Niciu
authors.affiliation: 3Experimental Therapeutics & Pathophysiology Branch,Intramural Research Program,National Institute of Mental Health,National Institutes of Health,Bethesda,MD,USA.
authors.forename: Erica M
authors.initials: EM
authors.lastname: Richards
authors.affiliation: 3Experimental Therapeutics & Pathophysiology Branch,Intramural Research Program,National Institute of Mental Health,National Institutes of Health,Bethesda,MD,USA.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Zarate
authors.affiliation: 3Experimental Therapeutics & Pathophysiology Branch,Intramural Research Program,National Institute of Mental Health,National Institutes of Health,Bethesda,MD,USA.
authors.forename: Maura L
authors.initials: ML
authors.lastname: Furey
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000033:anatomy & histology / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D061218:Depressive Disorder, Treatment-Resistant / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology* / Q000523:psychology; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000503:physiopathology; D013647:Task Performance and Analysis; D055815:Young Adult
keywords: N-back task; anxious depression; magnetoencephalography (MEG); major depressive disorder; neurobiology