Table 1.
Demographic and clinical characteristics of the sample
| Total (n = 27) | Non-responders (n = 12) | Responders (n = 15) | Non-responders vs. responders | |
|---|---|---|---|---|
| Age, years | 37.56±11.73 | 43.33±13.23 | 32.93±8.14 | U = 44.0, p = 0.024 |
| Sex (male/female), n | 10/17 | 4/8 | 6/9 | χ2 = 0.13, p = 0.726 |
| Ethnicity (Caucasian/non-Caucasian), n | 20/7 | 8/4 | 12/3 | χ2 = 0.62, p = 0.432 |
| Years of education | 16.15±1.98 | 16.00±2.56 | 16.27±1.44 | U = 83.0, p = 0.724 |
| Household income1, USD | 39,406±26,169 | 43,500±31,035 | 35,313±21,589 | U = 58.5, p = 0.643 |
| BMI | 26.86±4.81 | 29.39±4.37 | 24.84±4.26 | U = 38.5, p = 0.012* |
| Current tobacco users (users/non-users), n | 9/18 | 3/9 | 6/9 | χ2 = 0.68, p = 0.411 |
| Alcohol consumption2, number of drinks | 15.65±3.33 | 20.38±5.34 | 10.92±3.73 | U = 50.0, p = 0.199 |
| HDRS pre-treatment rating | 19.63±3.32 | 19.25±3.39 | 19.93±3.35 | U = 86.5, p = 0.860 |
| HDRS post-treatment rating | 9.78±4.58 | 13.75±2.77 | 6.60±2.92 | U = 6.0, p < 0.001* |
| PANAS negative scale pre-treatment rating3 | 41.75±9.58 | 41.44±9.57 | 42.00±10.05 | U = 49.0, p = 0.970 |
| PANAS negative scale post-treatment rating3 | 27.75±5.20 | 29.11±4.23 | 26.64±5.84 | U = 36.5, p = 0.321 |
| PANAS positive scale pre-treatment rating3 | 26.85±5.03 | 25.22±3.15 | 28.18±5.98 | U = 34.0, p = 0.235 |
| PANAS positive scale post-treatment rating3 | 37.85±10.44 | 33.00±5.20 | 41.82±12.13 | U = 33.5, p = 0.223 |
| YPAS vigorous activity index score4 | 259.08±336.21 | 374.22±427.37 | 166.96±214.39 | U = 64.5, p = 0.207 |
| Lifetime depression chronicity5, months | 141.24±115.99 | 158.58±122.91 | 123.89±121.39 | F = 0.48, p = 0.494 |
| Baseline subjective stress score6 | 24.61±6.19 | 26.20±5.67 | 23.38±6.51 | U = 47.5, p = 0.276 |
| Final SSRI dose7, mg/day | 99.07±34.31 | 112.50±34.86 | 88.33±32.55 | U = 52.0, p = 0.067 |
Values are expressed as means ± SD unless specified otherwise.
Significant at the 0.05 level.
Household income reported by 16 participants (8 responders and 8 non-responders).
Self-reported approximate number of drinks in the month prior to baseline blood draw; data were available for 24 participants (12 responders and 12 non-responders).
PANAS data only include those from participants who completed the scale at both the pre-treatment and the post-treatment time point; data were available for 20 participants (11 responders and 9 non-responders).
The YPAS vigorous activity index score is derived as follows: ‘frequency score’ × ‘duration score’ × participant's weight (in kg); frequency scores range from 0 to 4 and duration scores from 0 to 3 [28].
Data are age adjusted using ANCOVA; lifetime depression chronicity was estimated using the life history charting methods described by Post et al. [29]; only periods of time during which subjects met the DSM-IV criteria for MDD were counted.
Baseline subjective stress was measured using the PSS [27]; scores range from 0 to 40, where higher scores indicate greater levels of perceived stress; data were available for 23 participants (13 responders and 10 non-responders).
Data for final SSRI dose are based on the dose equivalency of sertraline [46].