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 width					Frequency
Scale	Baseline	Off	90/5	150/5	270/3	450/2	Off	5 Hz	20 Hz	50 Hz	130 Hz	185 Hz
Patient 1
HAM-D-17	33	26	25	21	17*	28	34	25	27	24	29	29
VAS-H	0	0	1.5	0	2.5↑	0	0	0	3	0	0	0
PANAS-P	14	15	13	21	16	15	11	11	16	15	10	12
PANAS-N	41	36	27↓	28	27↓	36	25	37	27	38	45	28
Patient 2
HAM-D-17	30	17	18	22	24	13*	26	17	13*	20	12*	27
VAS-H	1	3	4	0	1	6↑	0	1	1	1	4.5↑	0
PANAS-P	15	31	32↑	25	15	32↑	14	17	15	16	19	14
PANAS-N	34	18	21	28	29	16↓	14	17	20	16	16↓	16
Patient 3
HAM-D-17	33	26	23	27	22	16*	28	28	28	29	31	29
VAS-H	0.3	0.2	0.4	0.4	0.5	6↑	0.3	0.3	0.3	0.3	0.3	0.3
PANAS-P	17	16	20	12	25	37↑	14	17	15	16	19	14
PANAS-N	16	13	14	13	20	14	14	17	20	16	16	18
Patient 4
HAM-D-17	27	25	22	24	24	24	23	25	25	21	21	24
VAS-H	0.8	0.8	1	1.7	1.2	4.5↑	3	1.2	1.2	3.5↑	2.7	2.4
PANAS-P	17	15	15	16	14	16	19	16	14	14	17	16
PANAS-N	30	28	27	23↓	30	25	26	28	29	25	27	30

↓ = 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.