title: Increased cortical excitability with prefrontal high-frequency repetitive transcranial magnetic stimulation in adolescents with treatment-resistant major depressive disorder.
abstract: OBJECTIVE
  To examine changes in motor cortical excitability in adolescent subjects receiving 30 sessions of high-frequency prefrontal repetitive transcranial magnetic stimulation (rTMS).
  
  
  METHODS
  Eight adolescents with treatment-resistant major depressive disorder (MDD) enrolled in an open augmentation trial of 10 Hz rTMS. Resting motor thresholds were obtained by the visualization of movement method with a maximum likelihood threshold hunting computer algorithm at baseline and after every five sessions of rTMS. Motor threshold was recorded as the percentage of total machine output at each measurement.
  
  
  RESULTS
  Motor threshold data from baseline, weeks 2, 4, and 5 were included in a mixed model repeated measure analysis to examine a change in least square mean effect over time. The omnibus effect did not reach statistical significance (F=1.25, p=0.32). However, multiple comparisons from the overall model demonstrated a decrease in the least square mean motor threshold. The mean contrast from baseline to week 5 approached significance (p=0.07). Moreover, a post-hoc analysis with a Wilcoxon signed ranks test demonstrated a significant decrease at week 5 (p=0.03).
  
  
  CONCLUSIONS
  This suggests that high-frequency rTMS may increase cortical excitability in adolescents with treatment-resistant MDD.
authors.affiliation: Division of Child and Adolescent Psychiatry, Department of Psychiatry, UT Southwestern Medical Center Dallas, Dallas, Texas 75390-8589, USA. paul.croarkin@utsouthwestern.edu
authors.forename: Paul E
authors.initials: PE
authors.lastname: Croarkin
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Wall
authors.forename: Paul A
authors.initials: PA
authors.lastname: Nakonezny
authors.forename: Jeylan S
authors.initials: JS
authors.lastname: Buyukdura
authors.forename: Mustafa M
authors.initials: MM
authors.lastname: Husain
authors.forename: Shirlene M
authors.initials: SM
authors.lastname: Sampson
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Emslie
authors.forename: F Andrew
authors.initials: FA
authors.lastname: Kozel
mesh_terms: D000293:Adolescent; D000465:Algorithms; D003865:Major Depressive Disorder / Q000628:therapy*; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D016013:Likelihood Functions; D009044:Motor Cortex / Q000378:metabolism*; D010865:Pilot Projects; D018709:Statistics, Nonparametric; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D016896:Treatment Outcome