Table 1. Demographic, psychopathological, and clinical data.
| Patient group (n=27) | Healthy controls (n=25) | Test statistic (t/Χ2/U) | P value | |
|---|---|---|---|---|
| Age | 31.9 (7.1) | 33.0 (9.7) | U=322.00 | 0.78 |
| Gender (female/male) | 9/18 | 9/16 | Χ2=0.04 | 0.81 |
| Education in years | 12.2 (3.0) | 12.4 (3.6) | U=334.00 | 0.95 |
| Duration of illness in years | 9.2 (6.6) | — | — | — |
| Age of onset in years | 22.7 (6) | — | — | — |
| Chlorpromazine equivalents (mg/d) | 491.3 (349.5) | — | — | — |
|
Psychopathology | ||||
| PANSS positive | 11.2 (2.9) | — | — | — |
| PANSS negative | 14.7 (5.8) | — | — | — |
| PANSS general psychopathology | 23.5 (4.8) | — | — | — |
| PANSS total | 49.4 (11.2) | — | — | — |
| BNSS apathya | 14.8 (6.9) | — | — | — |
| BNSS diminished expressionb | 8.5 (7.2) | — | — | — |
| BNSS total | 24.6 (12.4) | — | — | — |
| CDSS Total | 1.6 (2.2) | — | — | — |
| GAF | 56.9 (9.6) | — | — | — |
|
Cognitionc | ||||
| Composite cognition score | −0.62 (0.89) | 0 (0.53) | t=3.0 | 0.01* |
| MWT IQ | 25.9 (5.8) | 27.6 (4.0) | t=1.2 | 0.23 |
Abbreviations: BNSS, Brief Negative Symptom Scale; CDSS, Calgary Depression Scale for Schizophrenia; GAF, Global Assessment of Functioning; MWT IQ, Multiple Word Test Intelligence Quotient; PANSS, Positive and Negative Syndrome Scale.
Note: Data are presented as means and s.d.’s. Potential group differences were investigated using two-sample t-tests for continuous and χ2-tests for categorical data. For non-normally distributed data Mann–Whitney U-tests were applied. All patients were receiving atypical antipsychotics at the time of testing.
Apathy=avolition, anhedonia, asociality.
Diminished expression=affective flattening or blunting, alogia.
Cognition data were z-transformed based on the data of the HC group for each test separately. The Composite cognition score was computed as the mean of the z-transformed test scores on subject level.
*P<0.05.