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Table 1 Socio-demographic and clinical characteristics of participants at baseline

From: Interplay of Val66Met and BDNF methylation: effect on reward learning and cognitive performance in major depression

 

Control group (N = 58)

Depressed group (baseline, N = 80)

Significance

Age (year, mean ± SD)

45.5 ± 12.0

45.4 ± 12.1

t = 0.08

p = 0.93

Gender (N, female/male)

31/27

47/33

X2 = 0.38

p = 0.53

Educational level (low/high)a

13/45

48/32

X2 = 19.3

p < 0.001**

Antidepressant use (%)

None

96.6

4

-

SSRI

1.7

41

 

SNRI

0

34

 

Other (TCA, mirtazapine, bupropion)

1.7

21

 

Early life stress event (% yes)b

10.3

38.0

X2 = 13.18, p < 0.001**

Depression severity (HDRS)

0.6 ± 1.3

16.9 ± 5.0

t = 27.54, p < 0.001**

Anhedonia (SHAPS)

19.2 ± 4.1

35.7 ± 7.6

t = 16.58, p < 0.001**

Cognitive performance (percentile ± SD)

SCWT

65.3 ± 25.3

29.6 ± 2.5

t = 8.28, p < 0.001**

TMT-A

67.8 ± 22.6

35.2 ± 23.0

t = 8.26, p < 0.001**

TMT-B

65.2 ± 26.6

38.3 ± 26.4

t = 5.86, p < 0.001**

DS-F

34.3 ± 25.5

29.7 ± 27.8

t = 0.99, p = 0.32

DS-B

45.9 ± 25.9

42.0 ± 25.5

t = 0.87, p = 0.39

  1. P-values are derived from statistical analysis using independent sample t-test for continuous variables or Chi-Square test for categorical variables
  2. aLow education = finished secondary school or less; High education = any additional education after secondary school
  3. bEarly life stress event: assessed by Structured Trauma Inventory Scale (STI)
  4. HDRS: Hamilton Rating Scale for Depression; SHAPS: Snaith–Hamilton Pleasure Scale; SCWT: Stroop Color and Word Test; TMT-A: Trial Making Test part A; TMT-B: Trial Making Test part B; DS-F: Digit Span Forward; DS-B: Digit Span Backward