Table 2.
Characteristics of participants
| Control | MDD | t or x2 | df | p | ||
|---|---|---|---|---|---|---|
| n | 199 | 200 | ||||
| Demographic information | ||||||
| Gender (frequency) | M | 93 (46.7%) | 96 (48.0%) | 0.064 | 1 | 0.8 |
| F | 106 (53.3%) | 104 (52.0%) | ||||
| Age (years, mean ± SD) | 28.7 ± 9.0 | 29.9 ± 8.9 | -1.229 | 397 | 0.195 | |
| 5-HTT genetics | ||||||
| 5-HTT LPR Genotypes (frequency) | ll | 21 (10.6%) | 10 (5.0%) | 6.788* | 2 | 0.034 |
| ls | 80 (40.2%) | 70 (35.0%) | ||||
| ss | 98 (49.2%) | 120 (60.0%) | ||||
| 5-HTT LPR Alleles (frequency) | l | 122 (30.7%) | 90 (22.5%) | 6.789* | 1 | 0.009 |
| s | 276 (69.3%) | 310 (77.5%) | ||||
| 5-HTT VNTR Genotypes (frequency) | STin2.12/12 | 167 (83.9%) | 172 (86.0%) | 1.224 | 2 | 0.542 |
| STin2.12/10 | 31 (15.6%) | 28 (14.0%) | ||||
| STin2.10/10 | 1 (0.5%) | 0 (0.0%) | ||||
| 5-HTT VNTR Alleles (frequency) | STin2.12 | 365 (91.7%) | 372 (93.0%) | 0.471 | 1 | 0.492 |
| STin2.10 | 33 (8.3%) | 28 (7.0%) | ||||
| Psychosocial variables | ||||||
| EPQ (score, mean ± SD) | Total | 192.5 ± 16.4 | 199.9 ± 16.0 | -4.526* | 397 | 0.000 |
| Extraversion | 58.5 ± 10.2 | 43.9 ± 10.8 | 13.87* | 397 | 0.000 | |
| Neuroticism | 44.1 ± 10.6 | 61.5 ± 9.7 | -17.1* | 397 | 0.000 | |
| Psychoticism | 47.5 ± 8.7 | 51.4 ± 10.6 | -3.993* | 397 | 0.000 | |
| Lie | 42.4 ± 10.3 | 43.0 ± 10.2 | -0.664 | 397 | 0.507 | |
| LES (score, mean ± SD) | Total | 25.2 ± 41.0 | 46.8 ± 65.8 | -3.929* | 397 | 0.000 |
| Positive | 9.44 ± 18.4 | 7.9 ± 18.8 | 0.845 | 397 | 0.399 | |
| Negative | 15.8 ± 29.3 | 38.9 ± 52.7 | -5.423* | 397 | 0.000 | |
| SSRS (score, mean ± SD) | Total | 38.1 ± 7.5 | 33.8 ± 7.4 | 5.747* | 397 | 0.000 |
| Objective | 9.1 ± 2.8 | 8.6 ± 2.6 | 1.865 | 397 | 0.063 | |
| Subjective | 21.0 ± 5.1 | 18.67 ± 5.3 | 4.541* | 397 | 0.000 | |
| Use | 8.1 ± 1.8 | 6.6 ± 2.1 | 7.697* | 397 | 0.000 | |
| TCSQ (score, mean ± SD) | Positive | 35.9 ± 6.2 | 25.7 ± 8.1 | 14.151* | 397 | 0.000 |
| Negative | 25.5 ± 7.1 | 35.2 ± 7.6 | -13.42* | 397 | 0.000 |
Frequency: frequencies of each subtype among their may category; t: t value in independent t-test; x2: x2 value in Pearson chi-square test; df: degrees of freedom; SD: standard deviation; 5-HTT: serotonin transporter; LPR: linked polymorphic region in the promoter; VNTR: variable-number-tandem-repeat region in the second intron; EPQ: Eysenck Personality Questionnaire; LES: Life Event Scale; SSRS: Social Support Rating Scale; TCSQ: Trait Coping Style Questionnaire;
*
p<0.05, considered statistically significant.