Table 1. Socio-demographic characteristics and whole-brain tissue volumes for PNS patients, non-PNS patients, and controls.
| PNS (n = 16) | non-PNS (n = 46) | Controls (n = 60) | p | |
| Socio-demographic variable | ||||
| Age at scan (years) | 24.2±4.3 | 23.7±3.4 | 24.8±3.3 | 0.285 |
| Parental SESa | 3.4±1.0 | 3.4±1.2 | 3.1±1.1 | 0.394 |
| Education levelb | 11.2±2.0 | 12.1±2.6 | 14.4±2.5 | <0.001 |
| Full Scale IQc | 97.6±18.2 | 95.5±12.2 | 107.9±14.9 | <0.001 |
| Handed, Right/Other | 12/4 | 40/6 | 55/5 | 0.193 |
| Sex, Male/Female | 13/3 | 32/14 | 40/20 | 0.529 |
| Whole-brain tissue volumes (ml) | ||||
| Grey matter | 624±56 | 643±60 | 658±71 | 0.161 |
| White matter | 605±65 | 596±64 | 618±71 | 0.264 |
| Cerebral-spinal fluid | 201±27 | 197±27 | 203±35 | 0.656 |
| Total intracranial | 1430±127 | 1437±121 | 1479±151 | 0.220 |
Abbreviations: PNS, persistent negative symptoms.
a
Hollingshead parental socioeconomic status: 1 = highest and 5 = lowest.
b
Education level measured as number of years completed; post-hoc tests revealed: PNS = non-PNS (p = 0.285); PNS < controls (p<0.001); non-PNS < controls (p<0.001).
c
Full Scale IQ measured with the WAIS-III (data were available for only 58 controls); post-hoc tests revealed: PNS = non-PNS (p = 0.870); PNS < controls (p = 0.034); non-PNS < controls (p<0.001).