Participant demographics and questionnaire data*
| Variable | Healthy controls n = 31 | Participants with MDD† n = 24 | p value | Effect size‡ |
|---|---|---|---|---|
| Sex, female/male | 17/14 | 15/9 | 0.57 | 0.063 |
| Age, yr | 29.74 ± 10.02 | 29.71 ± 10.93 | 0.99 | 0.003 |
| Education, yr | 16.94 ± 1.96 | 16.25 ± 2.56 | 0.22 | 0.303 |
| Beck Depression Inventory II score | 1.16 ± 2.02 | 24.96 ± 8.8 | < 0.001** | 3.728 |
| Mood and Anxiety Symptoms Questionnaire§ | ||||
| General Distress–Anxious Symptoms score | 13.27 ± 2.02 | 21.29 ± 7.02 | < 0.001** | 1.553 |
| Anxious Arousal score | 17.67 ± 1.03 | 23.79 ± 8.33 | < 0.005 | 1.031 |
| General Distress–Depressive Symptoms score | 13.67 ± 1.77 | 37.83 ± 10.36 | < 0.001** | 3.251 |
| Anhedonic Depression score | 44.97 ± 10.65 | 84.54 ± 10.39 | < 0.001** | 3.761 |
| Ruminative Response Scale | ||||
| Depression subscale score | 18.52 ± 4.70 | 32.54 ± 4.48 | < 0.001** | 3.054 |
| Brooding subscale score | 7.52 ± 2.03 | 12.63 ± 2.98 | < 0.001** | 2.004 |
| Reflection subscale score | 9.55 ± 3.57 | 12.13 ± 2.95 | 0.005 | 0.788 |
| Pittsburgh Sleep Quality Index score¶ | 2.87 ± 1.93 | 8.48 ± 2.73 | < 0.001** | 2.373 |
| Wechsler Test of Adult Reading score | 118.03 ± 10.56 | 117.32 ± 7.76 | 0.79 | 0.077 |
MDD = major depressive disorder.
↵* Values are mean ± standard deviation unless otherwise indicated. Statistics reflect between-group t tests except for sex (χ2).
↵† Of the 24 participants with MDD, 2 met the criteria for generalized anxiety (past 6 months); 2 reported agoraphobia (past month); 2 reported social anxiety (past month); 2 reported panic attacks (last month); and 7 reported at least one panic attack (lifetime).
↵‡ Cramer V for sex; otherwise Cohen d.
↵§ Data were missing for 1 participant from the control group.
↵¶ A score of 5 or less indicates good sleep quality; a score of greater than 5 indicates poor sleep quality.
↵** Significant following Bonferroni correction for multiple comparisons.