Table 3.
Simple correlations (r) among variables of stress, depression, and sleep quality
| Measure | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1. PSS score | – | .565*** | .821*** | .171 | .431** | .132 | .255 | .369* | −.329* | −.352* |
| 2. Salivary cortisol (wake) | – | – | .545*** | .317 T | .407* | .101 | .338* | .248 | −.358* | −.326 T |
| 3. CESD-10 score | – | – | – | .157 | .571*** | .150 | .269 T | .224 | −.187 | −.381* |
| 4. CRP | – | – | – | – | .220 | .278 | .312 T | .380* | −.439* | −.324 T |
| 5. PSQI overall score | – | – | – | – | – | .301 T | .256 | .021 | .026 | −.333* |
| 6. SOL | – | – | – | – | – | – | −.049 | .043 | −.081 | .096 |
| 7. % TST in N1 | – | – | – | – | – | – | – | −.029 | −.502*** | −.588*** |
| 8. % TST in N2 | – | – | – | – | – | – | – | – | −.569*** | −.478** |
| 9. % TST in N3 | – | – | – | – | – | – | – | – | – | .176 |
| 10. % TST in R | – | – | – | – | – | – | – | – | – |
T
.10 >p>.05,
*
p < .05,
**
p < .01,
***
p <= .001
Abbreviations: PSS = Perceived Stress Scale, CESD-10 = Center for Epidemiologic Studies Depression Scale (10-item version), CRP = C-reactive protein, PSQI = Pittsburgh Sleep Quality Index, SOL = sleep onset latency, TST = total sleep time.