Table 1.
Participant characteristics.
| Males | Females | rrMDD | |||||
|---|---|---|---|---|---|---|---|
| rrMDD mean ± SEM (range) | CONTROLS mean ± SEM (range) | p value | rrMDD mean ± SEM (range) | CONTROLS mean ± SEM (range) | p value | Males vs. females p value | |
| Subjects enrolled | 23 | 19 | 45 | 40 | – | – | |
| Age | 54 ± 1.4 (42–65) | 56 ± 1.2 (46–64) | 0.28 | 53 ± 1.2 (36–64) | 51 ± 1.2 (36–65) | 0.22 | 0.41 |
| Metabolomic samples analyzed | 23 | 19 | 44 | 40 | – | – | |
| Subjects living alone | 9 | 5 | 0.51 | 19 | 13 | 0.38 | 0.99 |
| Waist circumference (cm) | 101 ± 2.4 (86–127) | 104 ± 3.8 (91–129) | 0.56 | 92 ± 2.1 (67–124) | 85 ± 2.6 (57–111) | 0.05* | 0.01* |
| HAM-D score | 2.0 ± 0.4 (0–6) | 0.7 ± 0.4 (0–4) | 0.02* | 3.0 ± 0.3 (0–9) | 1.2 ± 0.3 (0–5) | 0.0003* | 0.12 |
| Age of 1st episode of MDD | 30 ± 2.1 (9–43) | n/a | 26 ± 1.7 (9–49) | n/a | – | 0.15 | |
| Duration of rMDD (years) | 25 ± 2.4 (6–50) | n/a | 27 ± 1.9 (3–55) | n/a | – | 0.39 | |
| Lifetime episodes of depression at entry | 9.7 ± 2.5 (2–45) | n/a | 8.1 ± 1.9 (2–60) | n/a | – | 0.63 | |
| Years since last depressive episode | 4.1 ± 0.8 (0.1–12) | n/a | 5.1 ± 0.8 (0.1–21) | n/a | – | 0.49 | |
| Subjects completing 2.5 years of follow-up | 20 | 19 | 0.23 | 42 | 40 | 0.50 | 0.33 |
| Subjects suffering recurrence | 11 | n/a | 24 | n/a | 0.99 | ||
| Median time to recurrence (IQR, months)a | 5.5 (1.9–7.6) | n/a | 10.1 (4.9–17.2) | n/a | 0.02* | ||
| Subjects taking CNS medicationsb | 1 | 0 | 0.99 | 3 | 1 | 0.62 | 0.99 |
| Vitamins, supplements, and OTC medications | 0.7 ± 0.19 (0–3) | 0.6 ± 0.22 (0–2) | 0.81 | 1.5 ± 0.22 (0–5) | 0.9 ± 0.24 (0–5) | 0.05* | 0.03* |
| Non-CNS prescription medications | 1.4 ± 0.36 (0–6) | 0.5 ± 0.23 (0–2) | 0.12 | 1.1 ± 0.24 (0–7) | 0.3 ± 0.1 (0–2) | 0.03* | 0.46 |
| Years of educationc | 16 ± 0.8 (9–20) | 16 ± 1.2 (9–25) | 0.90 | 14 ± 0.6 (9–20) | 14 ± 0.6 (10–25) | 0.22 | 0.04* |
| Ethnicity | |||||||
| Northern European | 22 | 19 | 0.99 | 35 | 34 | 0.42 | 0.08 |
| Non-N. European | 1 | 1 | 0.99 | 10 | 6 | 0.42 | 0.08 |
rMDD recurrent major depressive disorder in remission, HAM-D Hamilton depression rating scale, OTC over the counter, CNS central nervous system.
*Significant p value ≤ 0.05.
aData from N = 24 females and 11 males with recurrence in 2.5 years post-enrollment. Excludes data from N = 18 females and 9 males without recurrence. bNo subjects were taking antidepressants (selective or non-selective serotonin or norepinephrine reuptake inhibitors, or tricyclics). The numbers indicate the 1–3 subjects taking low-dose benzodiazepines. These subjects stopped the medication for 1–2 days before the blood draw, depending on the half-life of the drug, then to restarted as indicated. cYears of education: US system, High School=12; AA = 14; Bachelor’s=16; Master’s=18; JD = 19; MD, DO, or ND = 20; PhD=21; MD-PhD=25. Dutch system by Verhage score: 1 = 5 years, 2 = 6 years, 3 = 8 years, 4 = 9 years, 5 = 10 years, 6 = 15 years, 7 = 20 years.