Table 2. Performance of Machine Learning Model on Predicting the Improvement for Each Symptom of the HRSD-21 Depression Assessment Scale Using Pretreatment EEG Features and Baseline HRSD-21 Scores.
| Symptom and most important featuresa | Contribution, % | C index (95% CI) |
|---|---|---|
| Waking early | ||
| Waking early | 64.3 | 0.835 (0.808-0.858) |
| Self-critical | 8.8 | |
| Nighttime awakening | 8.5 | |
| Physical anxiety | ||
| Physical anxiety | 62.2 | 0.805 (0.772-0.83) |
| Paranoia | 3.6 | |
| O1 alpha absolute | 3.0 | |
| Trouble sleeping | ||
| Trouble sleeping | 57.3 | 0.773 (0.741-0.801) |
| T7-T3 alpha absolute ratio | 6.7 | |
| T7-T3 beta absolute ratio | 4.4 | |
| Self-critical | ||
| Self-critical | 52.8 | 0.743 (0.714-0.771) |
| Nighttime awakening | 7.3 | |
| Loss of interest | 5.7 | |
| Weight loss | ||
| Weight loss | 52.5 | 0.923 (0.896-0.953) |
| F7 gamma relative | 5.1 | |
| Fp2 delta relative | 4.4 | |
| Suicidal thoughts | ||
| Suicidal thoughts | 51.4 | 0.896 (0.873-0.923) |
| Agitation | 5.5 | |
| Appetite changes | 4.5 | |
| Nighttime awakening | ||
| Nighttime awakening | 49.0 | 0.786 (0.761-0.817) |
| Energy loss | 5.5 | |
| Diurnal variation | 5.4 | |
| Agitation | ||
| Agitation | 47.1 | 0.789 (0.759-0.822) |
| Unreality and nihilism | 3.0 | |
| F8 theta relative | 2.9 | |
| Appetite change | ||
| Appetite changes | 45.2 | 0.863 (0.84-0.886) |
| F3 alpha absolute | 2.4 | |
| Fp2 theta absolute | 2.4 | |
| Loss of interest | ||
| Loss of interest | 44.5 | 0.679 (0.647-0.710) |
| Energy loss | 8.4 | |
| Appetite changes | 5.2 | |
| Psychomotor retardation | ||
| Psychomotor retardation | 42.5 | 0.863 (0.833-0.893) |
| P4 alpha absolute | 2.7 | |
| Suicidal thoughts | 2.1 | |
| Unreality and nihilism | ||
| Unreality and nihilism | 40.9 | 0.951 (0.932-0.976) |
| T7-T3 beta relative ratio | 4.7 | |
| F7 beta relative | 3.3 | |
| Worrying | ||
| Worrying | 40.8 | 0.721 (0.688-0.751) |
| Psychomotor retardation | 7.0 | |
| F4 gamma absolute | 6.6 | |
| Libido loss | ||
| Libido loss | 40.8 | 0.777 (0.747-0.807) |
| T8-T4 theta and alpha relative ratio | 3.3 | |
| P8-T6 alpha relative ratio | 3.1 | |
| Obsessive thoughts | ||
| Obsessive thoughts | 39.8 | 0.882 (0.856-0.911) |
| Nighttime awakening | 9.2 | |
| O1 theta absolute | 7.3 | |
| Paranoia | ||
| Paranoia | 39.7 | 0.918 (0.888-0.951) |
| Oz alpha absolute | 6.7 | |
| T8-T4 beta absolute ratio | 4.7 | |
| Health preoccupation | ||
| Health preoccupation | 39.0 | 0.908 (0.872-0.944) |
| C4 theta relative | 6.8 | |
| T8-T4 beta relative ratio | 4.9 | |
| Diurnal variation | ||
| Diurnal variation | 38.3 | 0.831 (0.807-0.857) |
| Cp4 gamma absolute | 4.4 | |
| T7-T3 delta absolute ratio | 4.1 | |
| Energy loss | ||
| Energy loss | 32.5 | 0.676 (0.637-0.713) |
| Pz delta relative | 4.1 | |
| FCz delta relative | 3.4 | |
| Loss of insight | ||
| Loss of insight | 27.3 | 0.963 (0.939-1.000) |
| O1 delta absolute | 18.8 | |
| Oz delta absolute | 6.7 | |
| Depressed mood | ||
| Depressed mood | 23.2 | 0.662 (0.633-0.700) |
| P4 alpha absolute | 3.9 | |
| P4 theta-alpha absolute ratio | 2.7 |
Abbreviations: EEG, electroencephalograph; HRSD-21, 21-Item Hamilton Rating Scale for Depression.
a
The 3 most important features for each model, and their relative contributions computed using Shapley values, are reported.