Demographic and clinical characteristics of study participants
| Group; mean ± SD or no. (%)* | |||
|---|---|---|---|
| Characteristic | Bilateral (n = 40) | Unilateral (n = 40) | Sham (n = 41) |
| Age, yr | 46.4 ± 12.5 | 46.5 ± 14.1 | 48.1 ± 12.0 |
| Sex, male:female | 17:23 | 10:30 | 17:24 |
| Education, yr | 16.1 ± 3.4 | 15.6 ± 3.9 | 16.2 ± 3.2 |
| Age at illness onset, yr | 22.6 ± 12.9 | 21.5 ± 12.3 | 25.8 ± 12.9 |
| Recurrent episodes | 37 (92.5) | 37 (92.5) | 37 (90.2) |
| Duration of current episode, mo† | 51.5 ± 70.5 | 30.9 ± 64.1 | 46.9 ± 110.3 |
| No. of episodes‡ | 4.7 ± 4.1 | 4.1 ± 2.1 | 5.7 ± 6.7 |
| Current episode severity | |||
| Severe | 6 (15) | 10 (25) | 13 (31.7) |
| Moderate | 34 (85) | 30 (75) | 28 (68.3) |
| Comorbid anxiety disorder | 3 (7.5) | 5 (12.5) | 6 (14.6) |
| Medication hstory | |||
| ECT | 3 (7.5) | 3 (7.5) | 2 (4.9) |
| SSRI | 25 (62.5) | 18 (45) | 23 (56.1) |
| SNRI | 19 (47.5) | 19 (47.5) | 23 (56.1) |
| TCA | 7 (17.5) | 8 (20) | 4 (9.8) |
| Mirtazapine | 7 (17.5) | 3 (7.5) | 4 (9.8) |
| MAOI | 3 (7.5) | 3 (7.5) | 3 (7.3) |
| Buproprion | 15 (37.5) | 14 (37.5) | 14 (34.1) |
| Lithium | 3 (7.5) | 1 (2.5) | 1 (2.4) |
| Active medication during study | |||
| Benzodiazepine | 20 (50) | 16 (40) | 16 (39.0) |
| Atypical antipsychotic | 12 (30) | 10 (25) | 13 (31.7) |
| Antidepressant–antipsychotic combo | 12 (30) | 9 (22.5) | 12 (29.3) |
| Antidepressant and lithium | 3 (7.5) | 0 (0) | 1 (2.4) |
| Two antidepressants | 20 (50) | 19 (47.5) | 18 (43.9) |
| No antidepressant | 0 (0) | 4 (10) | 2 (4.9) |
| Past alcohol dependence | 2 (5) | 3 (7.5) | 3 (7.3) |
| ATHF for current episode§ | 8.9 ± 8.2) | 5.4 ± 2.6 | 7.8 ± 5.2 |
| Baseline HAMD | 24.1 ± 3.2 | 26 ± 3.4 | 25.5 ± 3.6 |
| Baseline BDI-II | 35.0 ± 10.4 | 35.8 ± 9.8 | 36.0 ± 10.1 |
| Left intensity % adjustment | −1.2 ± 4.0 | 0.7 ± 3.0 | −2.0 ± 7.1 |
| Right intensity % adjustment | −1.1 ± 4.1 | 1.0 ± 3.5 | −0.9 ± 6.1 |
| No. of treatments | 27.1 ± 7.3 | 26.2 ± 8.8 | 26.7 ± 8.4 |
ATHF = Antidepressant History Treatment Form; BDI-II = Beck Depression Inventory; ECT = electroconvulsive therapy; HAMD = Hamilton Rating Scale for Depression; TCA = tricyclic antidepressant; MAOI = monoamine oxidase inhibitor; SD = standard deviation; SNRI = serotonin norepinephrine reuptake inhibitor; SSRI = selective serotonin reuptake inhibitor.
↵* Unless indicated otherwise.
↵† n = 34 in the bilateral group, n = 38 in the unilateral group and n = 40 in the sham group.
↵‡ n = 21 in the bilateral group, n = 21 in the unilateral group and n = 18 in the sham group.
↵§ Significant difference among the groups (p = 0.037).