Table 2.
Main characteristics
| Total | Low BDNFa | High BDNF | χ²/t/U (df) p value | |
|---|---|---|---|---|
| 94 (100) | N = 47 (50%) | N = 47 (50%) | ||
| Socio-demographics | ||||
| Age, mean (SD) | 73.3 (8.1) | 74.3 (7.7) | 72.2 (8.4) | 1.3 (92) 0.20 |
| Gender, female | 64.0 (68.1) | 31.0 (66.0) | 33.0 (70.2) | 0.2 (1) 0.83 |
| Inclusion site: Amsterdam | 52.0 (55.3) | 18.0 (38.3) | 34.0 (72.3) | 11.0 (1) < 0.01 |
| Educational level | 0.4 (2) 0.82 | |||
| Low | 13.0 (15.9) | 8.0 (18.2) | 5.0 (13.2) | |
| Intermediate | 46.0 (56.1) | 24.0 (54.5) | 22.0 (57.9) | |
| High | 23.0 (28.0) | 12.0 (27.3) | 11.0 (28.9) | |
| Physical health and lifestyle characteristics | ||||
| Smoking, currently n = 78 | 21.0 (26.9) | 7.0 (20.0) | 14.0 (32.6) | 1.5 (1) 0.31 |
| No alcohol use n = 88 | 30.0 (34.1) | 27.0 (60.0) | 31.0 (72.1) | 1.4 (1) 0.27 |
| Physical comorbidities present | 77.0 (81.9) | 33.0 (70.2) | 44.0 (93.6) | 8.7 (1) 0.01 |
| Clinical characteristics | ||||
| MDD with psychotic features | 48.0 (51.1) | 27.0 (57.4) | 21.0 (44.7) | 1.5 (1) 0.30 |
| Late onset (>55 year) of depression | 54.0 (57.4) | 29.0 (61.7) | 25.0 (53.2) | 0.7 (1) 0.53 |
| Duration of index episode in months, median (IQR) n = 88 | 6.0 (10.0) | 5.0 (5.8) | 7.5 (11.3) | −2.1 (86) 0.04b |
| ATHF resistance score, median (IQR), n = 91 | 4.0 (5.0) | 4.0 (5.0) | 5.0 (5.0) | −1.3 (89) 0.20b |
| MMSE score before ECT-treatment, median (IQR), n = 84 | 25.5 (6.0) | 25.0 (6.0) | 26.0 (6.0) | 874.5; 0.95 |
| MADRS-scores, median (IQR) | ||||
| Before ECT-treatment | 34.0 (12.0) | 34.0 (10.0) | 34.0 (15.0) | 0.2 (92) 0.85 |
| After ECT-treatment | 6.0 (9.0) | 6.0 (6.0) | 7.0 (14.0) | −2.1 (92) 0.04b |
| Response to ECT treatment | 77.0 (81.9) | 43.0 (91.5) | 34.0 (72.3) | 5.8 (1) 0.03 |
| Remission after ECT treatment | 65.0 (69.1) | 39.0 (83.0) | 26.0 (55.3) | 8.4 (1) 0.01 |
| MRI characteristics | ||||
| MRI before ECT | 77.0 (81.9) | 39.0 (83.0) | 38.0 (80.9) | 0.1 (1) 1.00 |
| GCA score, median (IQR) | 1.0 (1.0) | 1.0 (1.0) | 1.0 (2.0) | 629.0; 0.21 |
| MTA score, median (IQR) | 1.0 (1.5) | 1.0 (1.0) | 1.0 (1.1) | 636.0; 0.27 |
| ECT characteristics | ||||
| Duration of ECT treatment (days), median (IQR) | 38.5 (24.0) | 38.0 (21.0) | 39.0 (24.0) | −0.5 (92) 0.64b |
| Continuation of psychotropic medication | 36 (38.3) | 15 (31.9) | 21 (44.7) | 1.6 (1) 0.29 |
| BDNF characteristics, mean (SD) | ||||
| BDNF (ng/ml) | ||||
| Pre-ECT | 18.1 (6.6) | 12.9 (3.8) | 23.3 (4.3) | −12.4 (92) < 0.01 |
| Post-ECT | 18.1 (6.2) | 14.5 (5.4) | 21.6 (4.8) | −6.3 (80) < 0.01 |
| Storage time (days) | 831.1 (294.6) | 826.5 (297.8) | 835.8 (294.5) | −0.2 (92) 0.88 |
Data shown as n (%) unless reported otherwise. In case of missing data, the number of complete cases (n=) for that variable is presented in the left column.
BDNF brain-derived neurotrophic factor, IQRinterquartile range, ng nanograms, ml millilitres, SD standard deviation
aBDNF levels have been split on the 50th percentile (17.9 ng/ml), resulting in low and high BDNF subgroups
bSkewed data, T-tests performed on log-transformed data