Table 1.
Demographic and clinical characteristics by diagnosis and genotype
| Depressed N=176 |
Non depressed N=88 |
df | Test Statistic |
p value | |
|---|---|---|---|---|---|
| BDNF genotype | 1 | x2= 7.47 | 0.01 | ||
| Val/Val | 104 | 67 | |||
| Val/Met and Met/met | 72 | 21 | |||
| Age, y | 69.07(7.02) | 70.13(5.60) | 212 | t=1.32 | 0.19 |
| Sex (percent female) | 62.50 | 70.45 | 1 | x2=1.64 | 0.20 |
| Education | 14.44(3.13) | 16.13(2.35) | 223 | t= 4.89 | <0.0001 |
| MMSE | 28.24(2.15) | 29.13(1.02) | 247 | t= 4.46 | <0.0001 |
| Left Hippocampal Volume n=173 | 2.99(0.43) | 2.98((0.46) | 171 | t=−0.19 | 0.85 |
| Right Hippocampal Volume n=173 | 3.10((0.39) | 3.14((0.45) | 171 | t= 0.70 | 0.49 |
| Total Cerebral volume n=173 | 1158.1(135.95) | 1150.8(121.96) | 171 | t= −0.35 | 0.73 |
| BDNF Genotype | |||||
| Val/Val N= 171 |
Val/met and Met/met N=93 |
df | Test statistic |
p value | |
| Percent depressed | 60.82(104/171) | 70.42(72/93) | 1 | x2= 7.47 | 0.01 |
| Age | 69.84(6.72) | 68.67(6.31) | 262 | t= 1.38 | 0.17 |
| Sex (percent female) | 62.57 | 69.89 | 1 | x2= 1.42 | 0.23 |
| Education | 15.16(2.91) | 14.72(3.14) | 262 | t= 1.13 | 0.26 |
| MMSE n = 251 | 28.63(1.84) | 28.39(1.98) | 249 | t= 0.96 | 0.34 |
| Age of onset of depression n=173 | 46.06 (19.99) | 43.39 (20.52) | 171 | t= 0.85 | 0.39 |
| Left Hippocampal volume n=173 | 2.94 (0.43) | 3.05 (0.44) | 171 | t= −1.69 | 0.09 |
| Right Hippocampal volume n=173 | 3.09 (0.43) | 3.15 (0.39) | 171 | t= −0.85 | 0.40 |
| Total cerebral volume n=173 | 1146.7 (128.33) | 1169.9 (135.36) | 171 | t= −1.13 | 0.26 |
Data presented as mean (SD). Age and education presented in years, MRI measures in milliliters. All comparisons between categorical variables made using the x2 test, and comparisons of continuous variables made using pooled, two-tailed t-tests except for comparisons of age, MMSE, and education between depressed and non-depressed subjects, which required the Satterthwaite t-test for unequal variances.