Clinical and demographic characteristics of the study sample (n = 5)
| Group, mean ± SD | ||
|---|---|---|
| Characteristic | OFF–ON, n = 2 | ON–OFF, n = 3 |
| Age at surgery, yr | 42.0 ± 9.9 | 50.7 ± 14.3 |
| Age at MDD onset, yr | 27.5 ± 0.7 | 20.3 ± 2.5 |
| No. of previous episodes | 3.5 ± 0.7 | 7.3 ± 6.1 |
| No. of previous hospitalizations | 6.5 ± 7.7 | 8.7 ± 8.1 |
| MADRS | ||
| Prerandomization | 2.0 ± 2.8 | 3.4 ± 2.5 |
| First month | 2.0 ± 1.4 | 9.4 ± 10.7 |
| Second month | 11.5 ± 2.1 | 8.4 ± 2.8 |
| Third month | 8.5 ± 12.0 | 7.7 ± 4.5 |
| Fourth month | 2.0 ± 2.8 | 9.7 ± 10.7 |
| Fifth month | 2.0 ± 2.8 | 15.4 ± 6.5 |
| Sixth month | 2.0 ± 2.8 | 14.0 ± 8.5 |
| End point | 4.0 ± 0.7 | 5.7 ± 2.1 |
| HAMD-17 | ||
| Prerandomization | 3.5 ± 2.1 | 3.7 ± 2.3 |
| First month | 6.0 ± 8.5 | 8.7 ± 1.2 |
| Second month | 9.0 ± 4.2 | 6.0 ± 2.0 |
| Third month | 8.5 ± 12.0 | 7.0 ± 5.6 |
| Fourth month | 3.0 ± 1.4 | 7.7 ± 7.4 |
| Fifth month | 2.5 ± 2.1 | 11.3 ± 5.0 |
| Sixth month | 2.0 ± 2.8 | 11.3 ± 5.0 |
| End point | 3.5 ± 0.7 | 5.3 ± 1.2 |
HAMD-17 = 17-item Hamilton Rating Scale for Depression; MADRS = Montogomery-Åsberg Depression Rating Scale; MDD = major depressive disorder; OFF–ON = 3 mo of sham stimulation followed by 3 mo of active stimulation; ON–OFF = 3 mo of active stimulations followed by 3 mo of sham stimulation; SD = standard deviation.