Table 2.
Unadjusted endophenotypes for schizophrenia (SZ) and community comparison subjects (CCS). All endophenotypes were expected to show larger mean values for CCS compared to SZ.
| Community comparison subjects (CCS) (n=517) |
Schizophrenia subjects (SZ) (n=345) |
P-valuea | Effect Sizea |
Difference (CCS – SZ) |
95% CIa | |||
|---|---|---|---|---|---|---|---|---|
| Mean (SD) [Range] |
Number missing (%) |
Mean (SD) [Range] |
Number missing (%) |
|||||
| Antisaccade (proportion correct) b |
0.82 (0.15) [0.04, 1.00] |
22 (4%) | 0.61 (0.26) [0.00, 0.98] |
61 (18%) | <0.0001 | 1.07 | 0.21 | (0.18, 0.24) |
| DS-CPT (d′) c | 2.54 (1.03) [− 0.12, 5.42] |
17 (3%) | 2.35 (1.14) [0.05, 5.42] |
63 (18%) | 0.014 | 0.18 | 0.20 | (0.04, 0.35) |
| CPT-IP 3-digit (d′) d | 2.99 (0.80) [0.92, 4.79] |
23 (4%) | 2.15 (0.84) [− 0.25, 4.52] |
70 (20%) | <0.0001 | 1.03 | 0.84 | (0.72, 0.96) |
| CPT-IP 4-digit (d′) e | 1.96 (0.84) [0.05, 4.26] |
23 (4%) | 1.28 (0.71) [− 0.17, 3.51] |
71 (21%) | <0.0001 | 0.85 | 0.68 | (0.56, 0.80) |
| LNS Forward (number correct) f |
14.3 (2.9) [7, 21] |
3 (1%) | 12.9 (2.9) [4, 21] |
13 (4%) | <0.0001 | 0.48 | 1.4 | (1.0, 1.8) |
| LNS Reordered (number correct) g |
11.4 (2.7) [2, 20] |
2 (<1%) | 9.1 (2.9) [1, 17] |
19 (6%) | <0.0001 | 0.81 | 2.3 | (1.9, 2.7) |
| CVLT total (number correct) h |
56.2 (10.3) [21, 80] |
5 (1%) | 41.6 (12.8) [6, 75] |
24 (7%) | <0.0001 | 1.29 | 14.6 | (13.1, 16.2) |
| CVLT semantic (number correct) i |
2.0 (2.4) [− 3.0, 8.5] |
5 (1%) | 0.4 (1.5) [− 2.2, 7.6] |
16 (5%) | <0.0001 | 0.79 | 1.6 | (1.4, 1.9) |
| Penn CNB | ||||||||
| Speedj | ||||||||
| Sensorimotor | 0.00 (1.00) [− 12.1, 1.3] |
25 (5%) | −0.80 (1.88) [− 12.8, 1.3] |
41 (12%) | <0.0001 | 0.58 | 0.80 | (0.61, 1.00) |
| Motor | 0.00 (1.00) [− 4.9, 4.6] |
27 (5%) | −0.70 (1.43) [− 5.9, 4.5] |
43 (12%) | <0.0001 | 0.59 | 0.70 | (0.53, 0.87) |
| Efficiency (mean of 2 z- scores)k |
||||||||
| Abstraction/mental flexibility |
0.00 (0.85) [− 4.5, 1.1] |
32 (6%) | −0.63 (1.15) [− 6.7, 0.9] |
49 (14%) | <0.0001 | 0.65 | 0.63 | (0.49, 0.77) |
| Face memory | 0.01 (0.84) [− 10.3, 1.4] |
23 (4%) | −0.71 (1.21) [− 10.4, 1.0] |
37 (11%) | <0.0001 | 0.70 | 0.70 | (0.56, 0.84) |
| Spatial memory | 0.00 (0.64) [− 3.2, 1.3] |
35 (7%) | −0.52 (0.98) [− 6.0, 1.4] |
54 (16%) | <0.0001 | 0.66 | 0.52 | (0.41, 0.64) |
| Spatial ability | 0.00 (0.78) [− 4.3, 1.2] |
33 (6%) | −0.27 (1.01) [− 6.3, 1.2] |
60 (17%) | <0.0001 | 0.31 | 0.27 | (0.14, 0.40) |
| Working memory | 0.00 (0.77) [− 3.5, 1.1] |
29 (6%) | −0.63 (1.13) [− 5.2, 1.1] |
68 (20%) | <0.0001 | 0.68 | 0.63 | (0.49, 0.76) |
| Emotion identification | 0.00 (0.78) [− 4.9, 1.5] |
25 (5%) | −1.19 (1.45) [− 7.9, 1.0] |
42 (12%) | <0.0001 | 1.10 | 1.19 | (1.03, 1.34) |
Abbreviations: CCS, community comparison subjects; CI, confidence interval; SD, standard deviation; CNB, Computerized Neurocognitive Battery; CPT-IP, Continuous Performance Test, Identical Pairs version; CVLT, California Verbal Learning Test; DS-CPT, Degraded Stimulus Continuous Performance Test; LNS, Letter-Number Span; SZ, schizophrenia subjects.
P-value and 95% CI for difference in means based on two-sample t-test assuming equal variances. Effect size computed using Cohen’s d statistic.
Proportion correct out of a maximum of 60 trials.
Overall signal/noise discrimination (d′).
Three-digit d′.
Four-digit d′.
After each sequence, the participant is asked to recall the numbers and letters in the same exact order, with no reordering of the stimuli. The number of digits and letters increases by one on each trial, from one up to a maximum length of 8 stimuli. Three sequences of the same length are presented during each trial. The test is discontinued when the subject fails three consecutive sequences of the same length. The score is the total number of correctly recalled sequences.
After each sequence, the participant is asked to repeat the numbers in ascending order first and then the letters in alphabetical order.
Trials 1–5 Free Recall Correct.
Total semantic clustering scores on trials 1–5.
Sensorimotor and motor values were reported as z-scores based on the mean and standard deviation for the community comparison subjects. Z-scores were based on values that had been multiplied by −1, so that a larger value indicated a better performance.
Efficiency scores were derived by averaging the z-scores (based on the mean and standard deviation for the community comparison subjects) for accuracy and speed.