Table 4.
Parameters of circadian activity rhythms in the schizophrenia subgroups and control group
| Group |
Statistical difference |
||||
|---|---|---|---|---|---|
| Subgroup I (n = 10) | Subgroup II (n = 10) | Control group (n = 21) | F(2,38) | P | |
| Period length, h: mean (95% CI) | 23.9 (23.7–24.1) | 24.3 (23.8–24.7) | 24.0 (23.99–24.02) | 3.044 | 0.059 |
| Delayed sleep phasea | 24.0 (24.0–24.0) | ns | |||
| Non-24 ha | 24.7 (23.2–26.3) | ns | |||
| Peak of activity cycle, h:min: mean (95% CI) | 15:28 (13:59–16:58) | 18:02 (17:08–18:56) | 16:13 (15:34–16:51) | 7.279 | 0.002b |
| Level of activity (M10 counts), mean (s.d.) | 17381 (11530) | 12935 (4039) | 21286 (5328) | 4.806 | 0.014c |
| Level of inactivity (L5 counts), mean (s.d.) | 1995 (1843) | 2012 (1169) | 1776 (757) | 0.815 | 0.832 |
| Amplitude, ratio: mean (s.d.) | 0.797 (0.139) | 0.776 (0.221) | 0.838 (0.073) | 2.32 | 0.112 |
ns, not significant.
a
The schizophrenia subgroup II were split into those with a delayed sleep phase (n = 6) and those with non-24 h sleep–wake cycles (n = 4).
b
Significant difference distinguishing schizophrenia subgroup II from schizophrenia subgroup I and control group.
c
Significant difference only between schizophrenia subgroup II and control group.