Table 1.
Sample characteristics.
| HC (n = 19) | SZ (n = 45) | Test statistics | ||
|---|---|---|---|---|
| (t/χ2/U) | p Value | |||
| Age (years) | 32.53 (9.45) | 34.00 (10.47) | t = −0.53 | 0.60 |
| Sex (male/female) | 9/10 | 31/14 | χ2 = 2.64 | 0.10 |
| Formal education (years)a | 14.39 (2.23) | 12.26 (3.88) | U = 227 | 0.003 |
| Number of hospitalizations | — | 5.42 (5.44) | — | — |
| Outpatients/inpatients | — | 24/21 | — | — |
| Smoking (yes/no) | 8/11 | 30/15 | χ2 = 3.34 | 0.068 |
| Number of psychotic episodes | — | 5.31 (5.14) | — | — |
| Illness onset (age, years) | — | 23.91 (6.88) | — | — |
| Illness duration (months) | — | 121.07 (101.28) | — | — |
| Chlorpromazine equivalents (mg/day) | — | 514.67 (444.82) | — | — |
| Clozapine (yes/no) | — | 9/36 | — | — |
| Class of antipsychotic (typical/atypical) | — | 1/43 | — | — |
| Antidepressant medication (yes/no) | — | 5/40 | — | — |
| Lorazepam (yes/no) | — | 3/42 | — | — |
| Body mass index | 23.40 (4.32) | 26.40 (4.66) | U = 250 | 0.009 |
| Psychopathology | ||||
| PANSS negative factorb | — | 15.49 (6.82) | — | — |
| PANSS positive factorc | — | 5.96 (2.70) | — | — |
| PANSS disorganized factord | — | 5.87 (2.48) | — | — |
| PANSS depressive factore | — | 5.33 (2.45) | — | — |
| Cognition | ||||
| Letter–Number Span Test | 20.16 (2.06) | 18.84 (1.93) | t = 2.44 | 0.018 |
| Symbol Coding Test | 81.94 (18.75) | 59.43 (13.28) | t = 4.62 | <0.001 |
| Cognitive scoref | 0 (0.68) | −0.88 (0.70) | t = 4.53 | <0.001 |
| Functioning | ||||
| PSP (total) | 97.05 (4.70) | 51.78 (14.42) | U = 2 | <0.001 |
Data are presented as means (standard deviations). P values < 0.05 are indicated in bold.
BMI body mass index, HC healthy controls, PANSS Positive and Negative Syndrome Scale, PSP Personal and Social Performance Scale, SZ schizophrenia.
aCompulsory education in Switzerland is 9 years.
bNegative factor: N1, N2, N3, N4, N6, G7.
cPositive factor: P1, P3, P5, G9.
dDisorganized factor; P2, N5, G11.
eDepressive factor: P4, P7, G8, G14.
fCognition data have been z-transformed based on the data of the healthy control group for each test separately. The cognitive score was computed as the mean of the z-transformed test scores on subject level.