Table 2

Results of blinded pulse width and frequency alterations in the stimulus optimization phase in patients undergoing subcallosal cingulate deep brain stimulation for treatment-resistant depression

Pulse widthFrequency
ScaleBaselineOff90/5150/5270/3450/2Off5 Hz20 Hz50 Hz130 Hz185 Hz
Patient 1
 HAM-D-173326252117*28342527242929
 VAS-H001.502.5↑0003000
 PANAS-P141513211615111116151012
 PANAS-N413627282736253727384528
Patient 2
 HAM-D-17301718222413*261713*2012*27
 VAS-H134016↑01114.5↑0
 PANAS-P153132↑251532↑141715161914
 PANAS-N341821282916141720161616
Patient 3
 HAM-D-17332623272216*282828293129
 VAS-H0.30.20.40.40.56↑0.30.30.30.30.30.3
 PANAS-P171620122537↑141715161914
 PANAS-N161314132014141720161618
Patient 4
 HAM-D-17272522242424232525212124
 VAS-H0.80.811.71.24.5↑31.21.23.5↑2.72.4
 PANAS-P171515161416191614141716
 PANAS-N302827233025262829252730
  • ↓ = maximal decrease; ↑ = maximal increase; HAM-D-17 = 17-item Hamilton Rating Scale for Depression; (11) PANAS = Positive and Negative Affective Scale, P for positive, N for negative; (20) VAS-H = visual analogue scale for happy mood.

  • * Signifies a 50% reduction in HAM-D-17 scores. Two patients inadvertently used flat affect (emotionally blunt) to score the sad feelings on the VAS sadness scale; therefore, those results are not reported. Frequency was kept constant at 130 Hz, and voltage was 2–4 V during pulse width changes. Pulse width and voltage were kept constant at 90 μs and 5 V during frequency changes. Patients 1, 2 and 3 showed 50% reduction in HAM-D-17 scores from the baseline following long pulse width (210 and 450 μs) stimulation. Only patient 2 showed clinical response with 20 and 130 Hz stimulation.