Table 1.
Means (SD) and Results of Random Effects Mixed Model Analyses for Demographic and Clinical Characteristics of PTSD and Non-PTSD Twin Pairs
| PTSD |
Non-PTSD |
Results of Random Effects Model |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Exposed (n = 18) | Unexposed (n = 18) | Exposed (n = 23) | Unexposed (n = 23) | Diagnosis |
Exposure |
Interaction |
||||
| t | p | t | p | t | p | |||||
| Age (yrs) | 52.3 (3.1) | 52.3 (3.1) | 51.9 (2.3) | 51.9 (2.3) | .54 | .590 | – | – | – | – |
| Education (yrs) | 14.0 (3.0) | 14.1 (2.8) | 14.7 (2.4) | 14.7 (2.6) | .83 | .413 | .06 | .949 | .20 | .841 |
| Estimated IQa | 105.8 (17.4) | 103.8 (12.6) | 118.7 (17.5) | 118.2 (16.2) | 2.95 | .005 | .55 | .586 | .33 | .740 |
| MASTb | 19.4 (16.8) | 4.4 (8.4) | 2.1 (4.4) | 2.2 (4.0) | 4.08 | .001 | 3.12 | .003 | 4.44 | .001 |
| Non-Combat Traumac (number of events) | 7.9 (2.6) | 5.7 (3.8) | 4.9 (3.9) | 4.3 (3.0) | 2.54 | .015 | 1.77 | .084 | 1.24 | .224 |
| Combat Severity | 7.6 (2.1) | – | 3.4 (2.6) | – | 5.46 | < .001 | – | – | – | – |
| CAPS | 72.9 (16.7) | – | 5.7 (7.3) | – | 17.36 | < .001 | – | – | – | – |
PTSD, posttraumatic stress disorder; MAST, Michigan Alcoholism Screening Test; CAPS, Clinician-Administered PTSD Scale (total symptom score).
a
Estimated IQ based on prorated performance on four subtests: Vocabulary, Arithmetic, Picture Arrangement, Block Design (Gilbertson et al. 2006).
b
Data for 1 PTSD (unexposed) and 2 non-PTSD (unexposed only) missing.
c
Lifetime number of non-combat potentially traumatic events. Data for 3 PTSD (Ex only) and 4 non-PTSD (1 = Ex and Ux, 3 = Ux only) missing.