title: Magnetoencephalography study of the effect of attention modulation on somatosensory processing in patients with major depressive disorder.
abstract: OBJECTIVE
  Although affective and/or attention modulation of somatosensory processing has been well studied, the biological bases of somatic symptoms in patients with major depressive disorder (MDD) have rarely been examined. To elucidate changes in somatosensory processing underlying somatic symptoms in patients with MDD, we conducted a magnetoencephalography study of patients with MDD and healthy controls.
  
  
  METHODS
  After median nerve stimulation, somatosensory evoked fields (SEF) were recorded in 10 patients with MDD and 10 sex-, age-, and height-matched healthy volunteers under somatosensory attending, visually attending, and non-attending conditions. The latencies and magnitudes of N20m and P60m SEF were examined.
  
  
  RESULTS
  In the MDD group, P60m latency was significantly prolonged, irrespective of attention modulation, whereas N20m latency and root mean squares N20m and P60m amplitudes remained unchanged. Prolonged P60m latency negatively correlated with the somatosensory threshold, which was relatively high in the MDD group. Prolonged P60m latency also negatively correlated with a state of anxiety during the examination, but not with depressive symptoms or psychotropic medication.
  
  
  CONCLUSIONS
  These results suggested that patients with MDD experience dysfunction in somatosensory information processing, approximately 60 ms after stimuli, irrespective of attentional conditions.
authors.affiliation: Sephiroth Clinic, Fukuoka, Japan.
authors.forename: Sumie
authors.initials: S
authors.lastname: Kurita
authors.affiliation: Department of Psychiatry and Neuroscience, Gunma University Graduate School of Medicine, Gunma, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Takei
authors.affiliation: National Center for Geriatrics and Gerontology, Aichi, Japan.
authors.forename: Yohko
authors.initials: Y
authors.lastname: Maki
authors.affiliation: Department of Psychiatry and Neuroscience, Gunma University Graduate School of Medicine, Gunma, Japan.
authors.forename: Suguru
authors.initials: S
authors.lastname: Hattori
authors.affiliation: Takasaki University of Health and Welfare, Gunma, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Uehara
authors.affiliation: Department of Psychiatry and Neuroscience, Gunma University Graduate School of Medicine, Gunma, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Fukuda
authors.affiliation: Department of Psychiatry and Neuroscience, Gunma University Graduate School of Medicine, Gunma, Japan.|International University of Health and Welfare Hospital, Tochigi, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Mikuni
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology
keywords: P60m component; magnetoencephalography; major depressive disorder; somatic symptoms; somatosensory evoked fields