Table 2 Main characteristics

From: Brain-derived neurotrophic factor as a possible predictor of electroconvulsive therapy outcome

 

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

  1. 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.
  2. BDNF brain-derived neurotrophic factor, IQRinterquartile range, ng nanograms, ml millilitres, SD standard deviation
  3. aBDNF levels have been split on the 50th percentile (17.9 ng/ml), resulting in low and high BDNF subgroups
  4. bSkewed data, T-tests performed on log-transformed data