Demographic and clinical characteristics of the study population
| Group; mean ± SD or no. (%) | ||||||
|---|---|---|---|---|---|---|
| Characteristic | Control n = 19 | FEP, treated n = 12 | FEP, untreated n = 17 | Statistic | p value | Bonferroni post hoc |
| Age, yr | 26.42 ± 4.11 | 27.42 ± 7.93 | 24.82 ± 1.38 | F2,47 = 0.749 | p = 0.48 | — |
| Female sex | 9 (47) | 6 (50) | 4 (24) | χ22 = 2.858 | p = 0.24 | — |
| Right-handedness | 18 (95) | 11 (92) | 16 (94) | χ22 = 0.124 | p = 0.940 | — |
| MWT | 113 ± 9.88 | 105 ± 19.63 | 103 ± 12.27 | F2,47 = 2.570 | p = 0.09 | — |
| BPRS total | 24.53 ± 1.7 | 42.75 ± 14.75 | 51.71 ± 15.53 | F2,47 = 24.687 | p < 0.001 | HC < FEP, treated HC < FEP, untreated |
| Suspiciousness (BPRS 9) | 1.00 ± 0.00 | 3.00 ± 1.71 | 3.47 ± 1.38 | F2,47 = 22.059 | p < 0.001 | HC < FEP, treated HC < FEP, untreated |
| Hallucinations (BPRS 10) | 1.00 ± 0.00 | 2.42 ± 2.15 | 3.53 ± 2.0 | F2,47 = 11.781 | p < 0.001 | HC < FEP, treated HC < FEP, untreated |
| Unusual thought content (BPRS 11) | 1.00 ± 0.00 | 3.25 ± 1.87 | 3.71 ± 1.9 | F2,47 = 17.431 | p < 0.001 | HC < FEP, treated HC < FEP, untreated |
| Conceptual disorganization (BPRS 15) | 1.00 ± 0.00 | 2.08 ± 1.31 | 2.06 ± 1.30 | F2,47 = 6.561 | p = 0.003 | HC < FEP, treated HC < FEP, untreated |
| SANS total | 0.00 ± 0.0 | 17.08 ± 16.21 | 21.82 ± 14.88 | F2,47 = 16.396 | p < 0.001 | HC < FEP, treated HC < FEP, untreated |
| GAF total | 88.63 ± 4.52 | 63.50 ± 9.65 | 53.06 ± 17.95 | F2,47 = 41.171 | p < 0.001 | HC < FEP, treated HC < FEP, untreated |
| Antidepressants | 0 (0) | 3 (25) | 4 (24) | χ22 = 5.381 | p = 0.07 | — |
| Cannabis | 4 (21) | 1 (8) | 7 (41) | χ22 = 4.308 | p = 0.12 | — |
| Cigarettes, no./d | 2.47 ± 5.834 | 9.42 ± 8.207 | 10.88 ± 11.522 | F2,47 = 4.618 | p = 0.015 | HC < FEP, untreated |
BPRS = brief psychiatric rating scale; FEP = first-episode psychosis; GAF = Global Assessment of Functioning; HC = healthy controls; MWT = Mehrfachwahl-Wortschatz-Intelligenz-Test, (a multiple choice vocabulary intelligence test); SANS = Scale for the Assessment of Negative Symptoms; SD = standard deviation.