Differences between first-episode and multiepisode subjects with schizophrenia
| Assessment item | Subject group; mean result (and SD) | t value | p value | |
|---|---|---|---|---|
| First-episode subjects* n = 111 | Multiepisode subjects* n = 76 | |||
| Initial assessment | ||||
| Positive symptoms | 17.5 (4.5) | 13.8 (5.8) | 4.98 | < 0.001 |
| Negative symptoms | 15.2 (6.1) | 16.9 (6.3) | −1.86 | NS |
| Executive function (WCST) | ||||
| Categories | 5.2 (1.6) | 3.2 (2.3) | 6.80 | < 0.001 |
| Perseverative errors | 14.9 (4.2) | 28.0 (20.5) | −5.00 | < 0.001 |
| Early information processing (SPAN) | 47.6 (7.5) | 47.6 (7.5) | −1.00 | NS |
| Visual attention (DS-CPT) | 86.4 (10.0) | 86.4 (10.0) | −0.64 | NS |
| Rey complex figure | ||||
| Copy | 35.1 (2.2) | 33.3 (3.1) | 3.80 | < 0.001 |
| Recall | 21.5 (7.0) | 15.5 (7.5) | 4.70 | < 0.001 |
| Verbal memory (Wechsler memory scale –revised) | ||||
| Immediate | 19.5 (19.9) | 18.5 (23.1) | 0.31 | NS |
| Delayed | 21.7 (18.9) | 16.5 (18.4) | 1.87 | NS |
| 1-year follow-up | ||||
| Positive symptoms | 11.8 (4.5) | 13.8 (5.8) | −2.67 | < 0.01 |
| Negative symptoms | 16.1 (6.1) | 16.9 (6.3) | −0.89 | NS |
| Executive function (WCST) | ||||
| Categories | 5.5 (1.3) | 3.2 (2.3) | 8.70 | < 0.001 |
| Perseverative errors | 12.1 (12.0) | 28.0 (20.5) | −6.66 | < 0.001 |
| Early information processing (SPAN) | 48.3 (7.9) | 47.6 (7.5) | −0.60 | NS |
| Visual attention (DS-CPT) | 84.8 (13.4) | 86.4 (10.0) | −0.85 | NS |
| Rey complex figure | ||||
| Copy | 35.1 (3.0) | 33.3 (3.1) | 3.90 | < 0.001 |
| Recall | 21.4 (7.6) | 15.5 (7.5) | 5.20 | < 0.001 |
| Verbal memory (Wechsler memory scale-revised) | ||||
| Immediate | 27.8 (22.8) | 18.5 (23.1) | 2.74 | < 0.01 |
| Delayed | 30.1 (23.3) | 16.5 (18.4) | 4.26 | < 0.01 |
Note: SD = standard deviation, NS = nonsignificant, WCST = Wisconsin Card Sorting Test, SPAN = span of apprehension, DS-CPT = degraded stimulus continuous performance test.
↵* First-episode subjects were assessed on entry to the Calgary Early Psychosis Treatment and Prevention Program and 1 year later; multiepisode subjects were assessed just once. The 2 sets of data for first-episode subjects were compared with the single set of data for multiepisode subjects.