Table 1.
Demographic, clinical and neurochemical measures.
| Healthy volunteers | First episode psychosis | t/x2 | df | p | |
|---|---|---|---|---|---|
| N | 65 | 46 | NA | NA | NA |
| Age mean (sd) | 25.85 (4.87) | 26.18 (4.42) | t = −0.357 | 102 | 0.722 |
| Sex (male/female) | 47/18 | 38/8 | x2 = 1.708 | 1 | 0.191 |
| Ethnicity (White Caucassian/Black African or Caribbean/Asian/mixed/missing data) | 24/9/12/3/17 | 17/11/11/0/7 | x2 = 0.819 | 1 | 0.365 |
| Diagnosis (Schizophrenia/Schizoaffective disorder/Bipolar Disorder/Psychotic Depression) | NA | 38/2/4/2 | NA | NA | NA |
| Global Assessment of Functioning score mean (sd) | 94.10 (10.29) | 47.71 (17.72) | t = 10.901 | 48 | <0.001 |
| WAIS digit symbol coding test score mean (sd) | 10.41 (3.02) | 8.73 (2.62) | t = 2.263 | 58 | 0.027 |
| PANSS positive mean (sd) | NA | 14.33 (7.54) | NA | NA | NA |
| PANSS negative mean (sd) | NA | 14.51 (8.46) | NA | NA | NA |
| PANSS general mean (sd) | NA | 45.00 (23.41) | NA | NA | NA |
| PANSS total mean (sd) | NA | 52.13 (24.50) | NA | NA | NA |
| Years of education after compulsory education*, mean (sd) | 4.36 (1.91) | 3.17 (2.42) | t = 2.389 | 74 | 0.019 |
| Current antipsychotic use (yes/no) | 0/65 | 0/46 | NA | NA | NA |
| Current benzodiazepine use (yes/no) | 0/65 | 0/46 | NA | NA | NA |
| Current antidepressant use (yes/no) | 0/65 | 0/46 | NA | NA | NA |
| Medication naïve (yes/no) | NA | 26/20 | NA | NA | NA |
*Years of compulsory education in the United Kingdom is age 16; NA = not applicable; SD = standard deviation. Group differences between patients and controls in demographic variables (age, sex, ethnicity) and clinical characteristics of the patient group.