Participant demographic characteristics
| Measure* | Healthy controls n = 21 | Patients with first-episode psychosis n = 19 | Statistic | p value |
|---|---|---|---|---|
| Age, yr | 23.4 ± 4.4 | 22.9 ± 4.4 | t38 = 0.38 | 0.71 |
| Female/male | 5/16 | 4/15 | χ21 = 0.04 | 0.83 |
| Smoker, yes/no | 0/21 | 4/15 | χ21 = 4.91 | 0.027¶ |
| Parental socioeconomic status† | 3.4 ± 3.3 | 4.6 ± 4.5 | t37 = 0.99 | 0.33 |
| RBANS score‡ | 95.1 ± 8.5 | 75.0 ± 15.6 | t33 = 4.84 | < 0.001¶ |
| Treatment duration, d | — | 358 ± 470 | — | — |
| BPRS rating§ | ||||
| Total | 20.8 ± 1.1 | 30.4 ± 8.4 | t33 = 4.79 | < 0.001¶ |
| Positive | 3.0 ± 0.2 | 4.8 ± 2.7 | t33 = 2.65 | 0.012¶ |
| Negative | 3.0 ± 2.4 | 5.6 ± 2.3 | t33 = 4.72 | < 0.001¶ |
BPRS = Brief Psychiatric Rating Scale; RBANS = Repeatable Battery for Assessment of Neuropsychological Status.
↵* Values are presented as mean ± standard deviation or n.
↵† Not available for 1 patient with first-episode psychosis. Ranks determined from the Diagnostic Interview for Genetic Studies (scale of 1–18); higher rank (lower numerical value) corresponds with higher socioeconomic status.
↵‡ Not available for 1 healthy control and 3 patients with first-episode psychosis.
↵§ Not available for 2 healthy controls and 2 patients with first-episode psychosis. Positive subscale: conceptual disorganization, hallucinatory behaviour and unusual thought content. Negative subscale: emotional withdrawal, motor retardation and blunted affect.
↵¶ Significant at p < 0.05.