Table 1.
Summary of characteristics of included studies.
| Authors. | Sample Size (Sex; Mean Age) | ADHD Subtypes | IQ and Comorbidities | Medications | PSG Recording (Setting; EEG Channels) | Sleep Measures | Main Results |
|---|---|---|---|---|---|---|---|
| Kirov et al. [22] | 17 ADHD (all M; 11.2 ± 2.0) vs. 17 HC (all M; 11.2 ± 2.3) |
All combined | Full-scale IQ ≥ 80 ADHD: 12 with dyslexia; 3 with conduct disorder; 1 with panic disorder; 1 with nocturnal enuresis |
11 ADHD stopped medications at least 3 days previous the experimental session | Laboratory recording with adaptation night; 1 EEG channel (C3) |
Macrostructure |
Children with ADHD had higher TBT, longer SPT, longer REM sleep duration and more sleep cycles than HC. |
| Miano et al. [23] | 20 ADHD (18 M; 9.3 range: 6–13) vs. 20 HC (18 M; 9.3 range: 6–13) |
2 inattentive 18 combined |
Full-scale IQ ≥ 70 ADHD: 10 with learning disabilities; 4 with mild neurological signs; 2 with language disorder; 4 with psychiatric comorbidities |
None | Laboratory recording with adaptation night; EEG channels not specified (at least 8 electrodes) |
Macrostructure CAP parameters |
Children with ADHD had lower TST, SPT, TBT and higher rate of SS than HC. Children with ADHD had lower total CAP rates and lower CAP rates during stage 2 than HC. Children with ADHD had lower CAP sequences and a reduced total A1 index in stages 1 and 2. |
| Gruber et al. [24] | 15 ADHD (10 M; 8.45 ± 1.39) vs. 23 HC (13 M; 8.58 ± 1.27) |
1 hyperactive 2 inattentive 12 combined |
Full-scale IQ ≥ 80 ADHD: 2 with PLMD HC: 2 with PLMD |
ADHD stopped medications at least 7 days previous the experimental session | Home recording; 8 EEG channels (F3, F4, C3, C4, P3, P4, O1, O2) |
Macrostructure | Children with ADHD had lower TST, lower percentage of REM sleep than HC. |
| Prihodova et al. [25] | 31 ADHD (26 M; 9.3 ± 1.7) vs. 26 HC (22 M; 9.2 ± 1.5) |
4 inattentive 27 combined |
Full-scale IQ ≥ 80 None |
None | Laboratory recording with adaptation night; 4 EEG channels (F4–C4, C4–P4, F3–C3, C3–P3, C4–A1, C3–A2) |
Macrostructure | No significant differences were found on sleep parameters between groups. |
| Prehn-Kristensen et al. [26] | 16 ADHD (not provided, 10.6 ± 0.88) vs. 16 HC (not provided, 11.00 ± 0.99) |
8 inattentive 8 combined |
full-scale IQ ≥ 85 ADHD: 4 with ODD. |
12 ADHD stopped medications 2 days previous the experimental session | Laboratory recording with adaptation night; 2 EEG channels (C3, C4) |
Macrostructure | No significant differences were found on sleep parameters between groups. A sleep-associated gain in reaction times of procedural memory task was positively correlated with the amount of stage 4 and REM sleep density in ADHD group. |
| Prehn-Kristensen et al. [27] | 12 ADHD (all M; 12.22 ± 0.52) vs. 2 HC (all M; 12.64 ± 0.24) |
Not provided | full-scale IQ ≥ 85 ADHD: 3 with ODD |
5 ADHD stopped medications 2 days previous the experimental session | Laboratory recording with adaptation night; 2 EEG channels (C3, C4) |
Macrostructure EEG power analysis at C3 (SWA; delta; theta; alpha; sigma, during REM and NREM sleep) Visual spindle detection in Stage 2 |
Children with ADHD had longer REM sleep duration and SOL than HC Children with. ADHD had shorter SWS latency and lower SE than HC. No significant differences on EEG power and spindle density were found between groups. Children with ADHD showed reduced sleep-associated consolidation of declarative memory. HC showed a correlation between sleep-associated recognition enhancement in declarative memory task (IAPS) and <1 Hz power during the first sleep cycle. NREM sleep duration in HC was positively correlated to sleep-related memory consolidation. |
| Gruber et al. [28] | 26 ADHD (17 M; 8.61 ± 1.27) vs. 49 HC (30 M; 8.61 ± 1.27) |
1 hyperactive 8 inattentive 17 combined |
full-scale IQ ≥ 80 ADHD: 8 with ODD; 2 with conduct disorder |
ADHD stopped medications 2 days previous the experimental session | Home recordings; 8 EEG channels (F3, F4, C3, C4, P3, P4, O1, O2) |
Macrostructure | No significant differences were found on sleep parameters between groups. |
| Kirov et al. [29] | 20 ADHD (19 M; 11.24 ± 2.31) vs. 19 HC (17 M; 11.26 ± 2.49) |
All combined | full-scale IQ ≥ 80 None |
11 ADHD stopped medications at least 7 days previous the experimental session | Laboratory recordings with adaptation night; 2 EEG channels (C3, C4) |
Macrostructure | Children with ADHD had higher TBT, TST, shorter REM sleep latency and longer REM sleep duration than HC. |
| Prihodova et al. [30] | 14 ADHD (12 M; 9.6 ± 1.6) vs. 12 HC (8 M; 9.0 ± 1.6) |
2 inattentive 12 combined |
IQ not specified, exclusion of mental retardation None |
None | Laboratory recording with adaptation night; 4 bipolar EEG channels (F4-C4, C4-P4, F3-C3, C3-P3, C4-A1, C3-A2) |
Macrostructure CAP analysis |
No significant differences were found on sleep parameters between groups. |
| Prehn-Kristensen et al. [31] | 16 ADHD (all M; 10.6 ± 0.95) vs. 16 HC (all M; 11.1 ± 0.95) vs. 20 HC adults (all M; 24.7 ± 2.8) |
8 inattentive 8 combined |
full-scale IQ ≥ 85 ADHD: 4 with ODD. |
12 ADHD stopped medications 2 days previous the experimental session. | Laboratory recordings with adaptation night; 4 EEG channels (F3, F4, C3, C4) |
Macrostructure EEG power analysis at F4. (SWA, delta and sigma during stage 2; theta during REM sleep) |
No significant differences were found on sleep parameters between children groups. After merged all healthy subjects (children and adults), a correlation between emotional memory (investigated by IAPS) and slow/delta during SWS was found. ADHD showed negative correlation between performance and <1 Hz power during SWS. The same correlation was found with theta activity during REM sleep. |
| Wiebe et al. [32] | 20 ADHD (13 M; 9.2 ± 1.6) vs. 46 HC (28 M; 8.8 ± 1.1) |
3 hyperactive 13 inattentive 4 combined |
mean IQ ADHD =100.4 mean IQ HC = 104.0 None |
ADHD stopped medications at least 2 days previous the experimental session. | Home recordings; 8 EEG channels (F3, F4, C3, C4, P3, P4, O1, O2) |
Macrostructure |
No significant differences were found on sleep parameters between groups. |
| Ringli et al. [33] | 9 ADHD (8 M; 11.9 range: 9.7–13.4) vs. 9 HC (8 M; 11.6 range: 9.6–14.2) |
All combined | mean IQ 120±15 None |
2 ADHD were treated at the day of experimental session. The second dose of medications was not given at the day of measurement. | Laboratory recording; High-density EEG (128 channels) |
Macrostructure EEG power analysis in all cortical channels. (SWA during NREM sleep) |
Children with ADHD had lower duration of stage 1 than HC. Children with ADHD showed higher SWA power over central than HC. |
| Akinci et al. [34] | 28 ADHD (20 M; 10 range: 8–12) vs. 15 HC (9 M; 10 range: 9–13) |
7 inattentive 21 hyperactive or combined |
full-scale IQ > 70. None |
None |
Laboratory recordings with adaptation nigh; 10 EEG channels |
Macrostructure CAP analysis |
Children with ADHD had higher REM sleep duration than HC. Children with ADHD had lower total CAP rates than HC. Children with ADHD had a reduced total A1 index in stage 2. |
| Virring et al. [35] | 76 ADHD (74% M; 9.6 ± 1.8) vs. 25 HC (68% M; 9.4 ± 1.5). |
5 hyperactive 14 inattentive 57 combined |
full-scale IQ > 70 ADHD: 6 with autism, 9 with internalizing comorbidity, 20 with externalizing comorbidity; 7 with tic disorder |
None |
Home recording; 6 EEG channels (F4, C4, O2, F3, C3, O1) |
Macrostructure |
Children with ADHD had higher numbers of sleep cycles, lower TST, lower stage 1 and 3 and longer REM sleep duration than HC. When children with comorbidity were excluded from the analyses, ADHD group showed only longer SOL than HC. |
| Saletin et al. [36] | 7 ADHD (5 M; 11.9 ± 0.9) vs. 14 HC (10 M; 11.7 ± 0.9) |
Not provided | mean IQ 110.3 ± 14.1. None |
ADHD stopped medications 2 days previous the experimental session. | Laboratory recordings with adaptation night; 4 EEG channels (C3, C4, O1, O2) |
Macrostructure EEG power analysis at C3, C4 (slow and fast sigma; SWA during Stage 2) |
Children with ADHD had lower TBT than HC. Children with ADHD showed reduced sigma power (spindle-related) than HC. Children with ADHD showed lower MST before sleep than HC, but no overnight gain was observed. MST precision was positively associated with slow spindle activity for the children with ADHD. |
| Cremone et al. [37] | 18 ADHD (13 M; 6.70 ± 1.07) vs. 15 HC (11 M; 6.73 ± 0.71) |
All hyperactive | IQ not specified, exclusion of mental retardation None |
ADHD stopped medications 2 days previous the experimental session | Laboratory recordings; 24 EEG channels |
Macrostructure EEG power analysis in all cortical channels. (delta during stage 2 and SWS; theta, during REM and NREM sleep) |
No significant differences were found on sleep parameters between groups. HC showed greater accuracy at go/noGo task in the morning vs. baseline after sleep. The performance was significantly associated with REM theta activity at F4. Children with ADHD showed greater theta activity in REM sleep than controls, however they revealed no changes in their performance after sleep. |
| Wiesener et al. [38] | 17 ADHD (All M; 11.3 ± 0.4) vs. 17 HC (all M; 11.1 ± 0.2) |
2 hyperactive 15 combined |
full-scale IQ ≥ 85 ADHD: 14 with ODD, 3 with conduct disorder; 6 with learning disabilities. |
13 ADHD stopped medications 2 days previous the experimental session |
Laboratory recording with adaptation night; 2 EEG channels (C3, C4) |
Macrostructure |
No significant differences were found on sleep parameters between groups. Children with ADHD did not show sleep-dependent consolidation of rewarded behavior. Their consolidation of rewarded behavior did not correlate with sleep. Instead, HC consolidated rewarded behavior better during a night of sleep than during a day awake. |
| Chin et al. [39] | 71 ADHD (54 M, 8.83 ± 1.86) vs. 30 HC (15 M, 8.48 ± 2.36) |
35 inattentive 36 hyperactive or combined |
full-scale IQ > 70 None |
ADHD had no medications in the 6 months previous the experimental session. | Laboratory recordings; 32 EEG channels |
Macrostructure |
Children with ADHD had lower percentage of SWS and higher apnea-hypopnea index than HC. |
ADHD, attention-deficit/hyperactivity disorder; IQ, intellectual quotient; PSG, polysomnographic; EEG, electroencephalographic; M, males; HC, healthy children; TBT, total bed time; SPT, sleep period time; REM, rapid eye movement; ODD, oppositional defiant disorder; CAP, cycling alternating pattern; TST, total sleep time; SS, stage shift; SWS, slow wave sleep; SE, sleep efficiency; PLMD, periodic limb movement disorder; SWA, slow wave activity; NREM, non-rapid eye movement; SOL, sleep onset latency; IAPS, international affective picture system; MST, motor sequence task.