Table 2.
Cohen's kappa coefficients and percentage of agreement between major depressive disorder symptom presentation at baseline and at episode recurrence at 2-, 4-, 6- and 9-year follow-upa
| IDS symptom | 2 years (n = 302) | 4 years (n = 229) | 6 years (n = 190) | 9 years (n = 154) | |
|---|---|---|---|---|---|
| Core symptoms | |||||
| Depressed mood | Baseline | 0.28 (63%) | 0.28 (65%) | 0.22 (61%) | 0.23 (62%) |
| 2 years | − | 0.33 (68%) | 0.14 (59%) | 0.16 (59%) | |
| 4 years | − | − | 0.21 (63%) | 0.26 (63%) | |
| 6 years | − | − | − | 0.45 (73%) | |
| Anhedonia | Baseline | 0.38 (74%) | 0.32 (71%) | 0.34 (71%) | 0.22 (70%) |
| 2 years | − | 0.37 (72%) | 0.32 (67%) | 0.16 (64%) | |
| 4 years | − | − | 0.40 (73%) | 0.46 (78%) | |
| 6 years | − | − | − | 0.42 (73%) | |
| Non-core symptoms | |||||
| Fatigue/loss of energy | Baseline | 0.32 (66%) | 0.23 (64%) | 0.28 (63%) | 0.25 (63%) |
| 2 years | − | 0.35 (69%) | 0.36 (68%) | 0.23 (62%) | |
| 4 years | − | − | 0.37 (69%) | 0.18 (61%) | |
| 6 years | − | − | − | 0.39 (70%) | |
| Appetite/weight change | |||||
| Appetite increase | Baseline | 0.41 (77%) | 0.40 (76%) | 0.19 (68%) | 0.20 (69%) |
| 2 years | − | 0.26 (72%) | 0.40 (82%) | 0.29 (75%) | |
| 4 years | − | − | 0.38 (81%) | 0.13 (68%) | |
| 6 years | − | − | − | 0.07 (79%) | |
| Appetite decrease | Baseline | 0.34 (80%) | 0.31 (83%) | 0.24 (77%) | 0.28 (82%) |
| 2 years | − | 0.22 (86%) | 0.35 (83%) | 0.25 (79%) | |
| 4 years | − | − | 0.07 (86%) | 0.10 (81%) | |
| 6 years | − | − | − | 0.52 (91%) | |
| Weight increase | Baseline | 0.26 (74%) | 0.18 (67%) | 0.21 (76%) | 0.10 (68%) |
| 2 years | − | 0.25 (73%) | 0.21 (80%) | 0.15 (72%) | |
| 4 years | − | − | 0.42 (82%) | 0.27 (79%) | |
| 6 years | − | − | − | 0.22 (71%) | |
| Weight decrease | Baseline | 0.19 (70%) | 0.08 (71%) | 0.09 (70%) | 0.10 (75%) |
| 2 years | − | 0.13 (79%) | 0.13 (80%) | 0.11 (77%) | |
| 4 years | − | − | 0.07 (80%) | 0.15 (83%) | |
| 6 years | − | − | − | 0.06 (76%) | |
| Sleep disturbance | |||||
| Insomnia | Baseline | 0.41 (74%) | 0.45 (74%) | 0.41 (73%) | 0.37 (72%) |
| 2 years | − | 0.47 (75%) | 0.43 (75%) | 0.38 (72%) | |
| 4 years | − | − | 0.43 (74%) | 0.31 (68%) | |
| 6 years | − | − | − | 0.35 (70%) | |
| Hypersomnia | Baseline | 0.34 (83%) | 0.36 (84%) | 0.38 (85%) | 0.14 (80%) |
| 2 years | − | 0.53 (88%) | 0.43 (87%) | 0.45 (87%) | |
| 4 years | − | − | 0.31 (87%) | 0.34 (85%) | |
| 6 years | − | − | − | 0.58 (91%) | |
| Psychomotor disturbance | |||||
| Psychomotor agitation | Baseline | 0.40 (71%) | 0.14 (58%) | 0.20 (70%) | 0.35 (66%) |
| 2 years | − | 0.25 (65%) | 0.50 (78%) | 0.27 (69%) | |
| 4 years | − | − | 0.33 (70%) | 0.16 (62%) | |
| 6 years | − | − | − | 0.22 (67%) | |
| Psychomotor retardation | Baseline | 0.40 (71%) | 0.33 (69%) | 0.34 (62%) | 0.25 (71%) |
| 2 years | − | 0.33 (70%) | 0.37 (70%) | 0.49 (78%) | |
| 4 years | − | − | 0.41 (72%) | 0.39 (71%) | |
| 6 years | − | − | − | 0.41 (71%) | |
| Worthlessness/guilt | Baseline | 0.34 (67%) | 0.35 (67%) | 0.31 (65%) | 0.32 (66%) |
| 2 years | − | 0.25 (62%) | 0.39 (70%) | 0.37 (69%) | |
| 4 years | − | − | 0.42 (71%) | 0.47 (73%) | |
| 6 years | − | − | − | 0.49 (75%) | |
| Concentration difficulties | Baseline | 0.33 (66%) | 0.23 (61%) | 0.29 (65%) | 0.26 (64%) |
| 2 years | − | 0.31 (66%) | 0.16 (58%) | 0.08 (54%) | |
| 4 years | − | − | 0.53 (77%) | 0.21 (61%) | |
| 6 years | − | − | − | 0.43 (73%) | |
| Suicidal ideation | Baseline | 0.38 (80%) | 0.32 (77%) | 0.28 (77%) | 0.42 (80%) |
| 2 years | − | 0.38 (79%) | 0.49 (85%) | 0.32 (78%) | |
| 4 years | − | − | 0.39 (80%) | 0.44 (80%) | |
| 6 years | − | − | − | 0.48 (79%) | |
IDS, Inventory of Depressive Symptomatology.
a.
IDS Likert scale ratings were recoded: 0 and 1 scored as 0 (symptom not present); 2 and 3 scored as 1 (symptom present). Kappa coefficients <0.20 indicate poor consistency, 0.21–0.40 fair consistency, 0.41–0.60 moderate consistency, 0.61–0.80 good consistency and >0.81 very good consistency.22