Table 3.
PTSD symptom clusters as predictors of amygdala and hippocampus grey matter volume.
| Step 1 | Step 2 | Step 3 | Step 4 | |||||
|---|---|---|---|---|---|---|---|---|
| Predictors | t-stat | P value | t-stat | P value | t-stat | P value | t-stat | P value |
| Left amygdala | ||||||||
| Age | − 0.97 | .334 | − 0.72 | .474 | − 0.82 | .413 | − 0.90 | .369 |
| Scanner site | − 1.10 | .272 | − 0.96 | .340 | − 0.99 | .326 | − 1.08 | .281 |
| TIV | 8.55 | < .001 | 7.55 | < .001 | 7.53 | < .001 | 7.41 | < .001 |
| Cluster B | – | – | − 0.08 | .939 | − 0.12 | .907 | 0.10 | .923 |
| Cluster C | – | – | 2.13 | .035 | 2.19 | .030 | 1.92 | .058 |
| Cluster D | – | – | 0.07 | .942 | 0.07 | .946 | 0.31 | .757 |
| Cluster E | – | – | − 2.84 | .005 | − 2.73 | .007 | − 2.74 | .007* |
| Anxiety | – | – | – | – | − 0.73 | .464 | − 0.67 | .506 |
| Depression | – | – | – | – | – | – | − 1.05 | .298 |
| R-squared | 0.446 | 0.523 | 0.526 | 0.531 | ||||
| Adjusted R-squared | 0.429 | 0.486 | 0.483 | 0.484 | ||||
| Right amygdala | ||||||||
| Age | − 0.92 | .359 | − 0.96 | .342 | − 0.93 | .355 | − 1.07 | .287 |
| Scanner site | − 2.53 | .012 | − 2.58 | .011 | − 2.56 | .012 | − 2.74 | .007 |
| TIV | 7.39 | < .001 | 6.11 | < .001 | 6.07 | < .001 | 5.97 | < .001 |
| Cluster B | – | – | − 1.17 | .244 | − 1.16 | .249 | − 0.80 | .424 |
| Cluster C | – | – | 3.02 | .003 | 2.98 | .003 | 2.56 | .012* |
| Cluster D | – | – | − 0.15 | .878 | − 0.15 | .879 | 0.25 | .803 |
| Cluster E | – | – | − 1.46 | .148 | − 1.45 | .151 | − 1.47 | .144 |
| Anxiety | – | – | – | – | 0.06 | .951 | 0.17 | .865 |
| Depression | – | – | – | – | – | – | − 1.71 | .089 |
| R-squared | 0.376 | 0.452 | 0.452 | 0.469 | ||||
| Adjusted R-squared | 0.357 | 0.409 | 0.403 | 0.415 | ||||
| Left hippocampus | ||||||||
| Age | − 0.69 | .491 | − 0.58 | .560 | − 0.34 | .736 | − 0.42 | .678 |
| Scanner site | 0.99 | .322 | 1.22 | .225 | 1.30 | .196 | 1.20 | .234 |
| TIV | 9.91 | < .001 | 8.52 | < .001 | 8.60 | < .001 | 8.48 | < .001 |
| Cluster B | – | – | 0.53 | .598 | 0.62 | .538 | 0.81 | .421 |
| Cluster C | – | – | 1.05 | .297 | 0.88 | .381 | 0.64 | .524 |
| Cluster D | – | – | 0.22 | .828 | 0.23 | .819 | 0.46 | .647 |
| Cluster E | – | – | − 1.32 | .189 | − 1.50 | .136 | − 1.51 | .134 |
| Anxiety | – | – | – | – | 1.56 | .121 | 1.63 | .107 |
| Depression | – | – | – | – | – | – | − 1.01 | .314 |
| R-squared | 0.541 | 0.556 | 0.567 | 0.572 | ||||
| Adjusted R-squared | 0.527 | 0.521 | 0.529 | 0.529 | ||||
| Right hippocampus | ||||||||
| Age | − 0.44 | .659 | − 0.39 | .699 | − 0.16 | .874 | − 0.26 | .793 |
| Scanner site | 1.24 | .219 | 1.52 | .131 | 1.60 | .113 | 1.47 | .145 |
| TIV | 9.49 | < .001 | 8.00 | < .001 | 8.06 | < .001 | 7.95 | < .001 |
| Cluster B | – | – | 0.63 | .533 | 0.71 | .480 | 0.96 | .338 |
| Cluster C | – | – | 1.03 | .306 | 0.87 | .386 | 0.57 | .573 |
| Cluster D | – | – | − 0.32 | .751 | − 0.31 | .757 | 0.00 | .996 |
| Cluster E | – | – | − 0.48 | .634 | − 0.65 | .521 | − 0.65 | .515 |
| Anxiety | – | – | – | – | 1.46 | .149 | 1.54 | .126 |
| Depression | – | – | – | – | – | – | − 1.32 | .189 |
| R-squared | 0.522 | 0.533 | 0.544 | 0.553 | ||||
| Adjusted R-squared | 0.507 | 0.497 | 0.503 | 0.508 | ||||
Within the PTSD group, greater hyperarousal symptoms significantly predicted less left amygdala volume, even after controlling for anxiety and depression (denoted *); while greater avoidance symptoms significantly predicted greater right amygdala volume, even after controlling for anxiety and depression (denoted *). PTSD symptom cluster scores within the PTSD group did not significantly (all ps > .0125) predict left or right hippocampal volume. TIV = total intracranial volume.