Table 1.
Patient demographic, clinical, and neurophysiological characteristics
| Older adults with depression (n = 92) | Older healthy adults (n = 41) | Younger adults with depression (n = 30) | Younger healthy adults (n = 30) | Statistic | p value | |
|---|---|---|---|---|---|---|
| Demographic characteristics | ||||||
| Age (years) | 66.8 ± 6.1 | 69.0 ± 8.3 | 44.8 ± 10.5 | 44.9 ± 10.8 | F3,189 = 105.7 | <0.001 |
| Sex | 62 F/30 M | 23 F/18 M | 20 F/10 M | 18 F/12 M | χ2(3) = 1.9 | 0.60 |
| Education (years) | 14.5 ± 2.9 | 15.4 ± 2.3 | NA | 16.2 ± 2.9 | F2,158 = 4.9 | 0.009 |
| Handedness | 66 R/8 La | 40 R/1 L | 30 R/0 L | 28 R/2 L | χ2(6) = 11.3 | 0.08 |
| Clinical characteristics | ||||||
| MADRS score | 25.7 ± 5.4 | NA | NA | NA | − | − |
| HAM-D score | NA | − | 25.6 ± 3.0 | − | − | − |
| MMSE score | 29.0 ± 1.1 | NA | NA | NA | − | − |
| CIRS-G score | 6.5 ± 3.7 | NA | NA | NA | − | − |
| Late-onset (≥ 60 years), no. (%) | 19 (21%) | − | − | − | − | − |
| Treatment-resistant, no. (%)b | 69 (75%) | − | 19 (63%) | − | χ2(1) = 1.5 | 0.22 |
| Comorbid anxiety disorder, no. (%) | 32 (35%) | − | 14 (47%) | − | χ2(1) = 1.4 | 0.24 |
| Medication use, no. (%)c | ||||||
| Antidepressants | 45 (49%) | − | 18 (60%) | − | χ2(1) = 1.1 | 0.29 |
| Benzodiazepines | 27 (29%) | − | 11 (37%) | − | χ2(1) = 0.6 | 0.45 |
| Neurophysiological characteristics | ||||||
| TS intensity (%) | 63.5 ± 15.3 | 63.7 ± 12.7 | NA | 59.5 ± 12.7 | F2,159 = 1.0 | 0.38 |
| TS mean MEP amplitude (mV) | 0.98 ± 0.47 | 0.86 ± 0.34 | 0.95 ± 0.24 | 0.93 ± 0.30 | F3,185 = 0.9 | 0.45 |
Abbreviations: R = right, L = left, MADRS = Montgomery-Asberg Depression Rating Scale, MMSE = Mini-Mental State Examination, HAM-D = Hamilton Rating Scale for Depression, RMT = resting motor threshold (% maximum stimulator output), NA = not available, TS = test stimulus, TS intensity = intensity required to elicit 1 mV peak-to-peak MEP amplitude (% maximum stimulator output), MEP = motor-evoked potential
a Handedness data missing for 18 patients
b Treatment resistance defined as non-response to an adequate antidepressant trial (a score ≥ 3 on the Antidepressant Treatment History Form)
c Medication use at the time of neurophysiological testing