Table 1.
Subject characteristics and PSG technical details (N = 11).
| Study | Subjects | Age (in years) | Sex (M/F) | Illness duration (in years) | Medication status of psychosis/schizophrenia group | Symptom severity | Sleep study technical details |
|---|---|---|---|---|---|---|---|
| Kaskie et al. [38] | 27 FEP | 23.2 ± 5.8 | 17/10 | NR | 15 antipsychotics naïve 12 on medications |
PANSS Positive 20.4 ± 4.6 Negative 16.3 ± 5.0 |
High density EEG Single night Slow: 12–14 Hz Fast: 14–16 Hz |
| 23 healthy controls | 24.7 ± 5.7 | 16/7 | |||||
| Baandrup et al. [35] | 37 schizophrenia No control |
46.6 ± 9.54 | 24/13 | 21.27 ± 11.26 | On medications | PANSS Scores NR |
Standard PSG Single night C3/C4 Slow: 11–13 Hz Fast: 13–16 Hz |
| Schilling et al. [39] | 17 schizophrenia | 29.94 ± 10.60 | 10/7 | 5.0 ± 5.4 | On medications (Antipsychotics monotherapy) | PANSS Positive 15.1 ± 5.0 Negative 16.1 ± 4.0 General 35.0 ± 8.3 |
Standard PSG Analysis of second night data F3/F4 Slow: 9–12 Hz Cz Fast: 12–15 Hz |
| 13 first-degree relatives | 33.31 ± 14.05 | 6/7 | – | ||||
| 17 healthy controls | 26.53 ± 8.78 | 11/6 | – | ||||
| Wamsley et al. [40] | 21 schizophrenia | 34 ± 9 | 17/4 | 10 ± 8 | On medications | PANSS Positive 12 ± 5 Negative 15 ± 5 General 28 ± 10 |
Standard PSG Analysis of second night data F3/F4 12–15 Hz |
| 17 healthy controls | 36 ± 7 | 14/3 | – | ||||
| Goder et al. [36] | 16 schizophrenia | 28.3 ± 6.1 | 7/9 | 6 ± 4 | On medications | PANSS Total: 57 ± 8 (mild) Subscores NR |
Standard PSG Analysis of second night data C3/C4 12–16 Hz |
| 16 healthy controls | 29.4 ± 6.4 | 9/7 | – | ||||
| Manoach et al. [11] | 15 FEP | 28 ± 8 | 11/4 | NR | Antipsychotics naïve | FEP: SANS total: 14 ± 3 SAPS total: 9 ± 3 Other psychotic disorders: SANS total: 12 ± 3 SAPS total: 8 ± 5 |
Standard PSG Analysis of second night data C3/C4 12–15 Hz |
| 11 Other psychotic disorders | 27 ± 7 | 6/5 | |||||
| 25 healthy controls | 27 ± 7 | 16/9 | |||||
| 19 Relatives | 14 ± 4 | 9/10 | |||||
| Ramakrishnan et al. [41] | 20 schizophrenia No control |
41.3 ± 8.7 | 8/12 | 13.4 ± 8.4 | On medications | PANSS Positive 6.5 ± 5.0 Negative 14.5 ± 5.7 General 32.5 ± 8.9 |
Standard PSG Analysis of second night data C3/C4 Criteria of spindle unclear Only the spindles during the last quarter of sleep were manually evaluated |
| Keshavan et al. [34] | 27 FEP No control |
27.2 ± 7.3 | 18/9 | 8.4 ± 7.6 | Antipsychotics naïve | SAPS, SANS Scores NR | Standard PSG Analysis of second night data C3/C4 |
| Ferrarelli et al. [10] | 49 schizophrenia | 38.2 ± 10.6 | 33/16 | 15 ± 8 | On medications | PANSS Positive 21.5 ± 4.2 Negative 22.3 ± 4.8 General 45.2 ± 6.9 |
High-density EEG Single night Slow: 12–14 Hz Fast: 14–16 Hz |
| 44 healthy controls | 36.7 ± 7.8 | 29/15 | – | ||||
| Ferrarelli et al. [9] | 18 schizophrenia | 39.6 ± 9.5 | 13/5 | NR | On medications | PANSS Positive 20.6 ± 3.7 Negative 21.2 ± 3.5 General 42.9 ± 6.2 |
High-density EEG Single night 12–15 Hz |
| 17 healthy controls | 37.0 ± 10.1 | ||||||
| Forest et al. [42] | 8 FEP | 31.0 ± 19.9 | 6/2 | NR | Antipsychotics naïve | PANSS Positive 21.0 Negative 23.3 General 85.6 (SD not provided) |
Standard PSG Two nights (3 FEP patients could only attend a single night) C3/C4 12–15 Hz |
| 8 healthy controls | 21.4 ± 4.9 | 6/2 |
Abbreviation: EEG, electroencephalography; FEP, first episode psychosis; NR, not reported; PANSS, Positive and Negative Syndrome Scale; PSG, polysomnography; SAPS, Scale for the Assessment of Positive Symptoms; SANS, Scale for the Assessment of Negative Symptoms.