Abstract
Background
Adequate sleep is crucial for children’s health, especially for children with ADHD and concurrent sleep problems. There is a need for more studies focusing on sleep problems in children with ADHD as these problems may exacerbate ADHD symptoms and vice versa, impacting negatively on everyday life. The aim of this study was to investigate the differences in health-related factors between children with ADHD without clinically relevant sleep problems and those with clinically relevant sleep problems after a sleep intervention.
Methods
This cross-sectional study involved 83 children diagnosed with ADHD and sleep problems, 46 boys and 37 girls; aged 6–14 years, divided into two groups after a sleep intervention according to the parent-reported Children’s Sleep Habits Questionnaire (CSHQ) and a cut-off for clinically relevant sleep problems. Data from a 16-week follow-up of the sleep intervention were analysed in terms of the following health-related measures: The Insomnia Severity Index (ISI), The short form of State-Trait Anxiety Inventory (Short-STAI), The Child Outcome Rating Scale (CORS), The EQ-5D-Y-3L (child-reported), and The Swanson, Nolan, and Pelham Rating Scale (SNAP-IV) (parent-reported). The Mann-Whitney u-test, Independent samples t-test, and Chi-square/Fisher’s exact test were used for the analysis.
Results
Forty-two of the 83 children (50.6%) were grouped as having clinically relevant sleep problems and 41 (49.4%) as being without the same. The results indicated that the group without clinically relevant sleep problems reported less insomnia (ISI, total score p = 0.011), less tension in the anxiety scale (Short-STAI, tense p = 0.047), and their parents reported less ADHD symptoms (SNAP-IV, total score for attention deficit, p < 0.001). No group differences were observed for life functioning (CORS) or health-related quality of life (EQ-5D-Y-3 L).
Conclusions
This study showed that children with ADHD without parent-reported clinically relevant sleep problems had fewer health-related issues after a sleep intervention, including self-reported insomnia, tension, and parent-reported ADHD symptoms, compared to children with clinically relevant sleep problems. Longitudinal studies are necessary to fully comprehend the long-term impact of sleep problems and various health-related factors in this cohort.
Keywords: Attention-deficit/hyperactivity disorder, Children, Health, Sleep
Background
Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder, characterized by attention deficit and hyperactivity with or without impulsivity and difficulties in managing and controlling emotions and mood [1]. In addition to cognitive and behavioral impairments, children with ADHD have been shown to be afflicted with low sleep quality and increased daytime sleepiness [2]. Insufficient sleep is a major concern for children in general, but especially for children with ADHD [1]. The prevalence of sleep problems has been found to vary between 25% and 85% in children with ADHD [3–5] in comparison with the prevalence of sleep problems of 20–30% in children without neurodevelopmental disorders [6]. Since adequate sleep is crucial for children’s behavior and daily function, it is an important part of children’s overall health [7]. Common sleep problems in ADHD may stem from a hypo-arousal state, from delayed sleep onset latency and thus bedtime resistance, from sleep anxiety, parasomnia [8], sleep disordered breathing [9] and from restless legs syndrome, which is a common comorbidity to ADHD in children and often related to iron deficiency [9–11]. Inadequate sleep among children diagnosed with ADHD is associated with academic challenges [4, 12], poorer mental health and lower quality of life [13].
Numerous studies on sleep problems in children with ADHD have focused on variables such as comorbidities and pharmacological treatments [14–18]. However, some of these have overlooked other important health-related factors such as insomnia, anxiety, and ADHD symptoms as well as overall well-being and how the children function in their everyday life. Understanding the complexity of sleep problems in children with ADHD is crucial, and although studies specifically addressing sleep problems in this group of children have been performed [19, 20] more research is needed.
The aim of this study was to investigate the differences in health-related factors between children with ADHD without clinically relevant sleep problems and those with clinically relevant sleep problems after a sleep intervention.
Methods
Study design, recruitment, and participants
The current study had a cross-sectional design and included data collected from a randomized controlled trial with a sleep intervention with weighted blankets [21] targeted towards children aged 6–14 years with ADHD and sleep problems. The participants were recruited between January 2020 and January 2022 when attending an ADHD unit at a Child and Adolescent Mental Health Service (CAMHS) in the south of Sweden. Children were enrolled to the specific ADHD unit because they did not have significant comorbidities or complex social challenges [22]. Those with significant comorbidities or complex social challenges were treated at other units at CAMHS. Children with recently diagnosed ADHD and concurrent sleep problems were considered eligible for inclusion. Children were triaged to the unit when the structured Brief Child and Family Phone Interview indicated a probable diagnosis of ADHD. The assessment at the unit was based on a written report by a teacher at the child’s school regarding strengths and difficulties with learning and social functioning at school, a teacher ADHD rating scale, a thorough diagnostic interview with the child and the parent(s), and an observation of the child. The diagnostic interview was carried out by a resident, and the diagnosis was made based on the DSM-5 criteria and confirmed by a senior child and adolescent psychiatrist at the end of each assessment. Medication was also prescribed in about half of the cases. Sleep problems were screened by a healthcare professional from CAMHS utilizing three questions (scored as 0–1, 2–4, or 5–7 days per week) to the parent from the Swedish version of the Children’s Sleep Habits Questionnaire (CSHQ-SWE) [23, 24], namely: Question 2 (“Child falls asleep within 20 minutes after going to bed”, scoring criteria 0–1 or 2–4 days per week), question 9 (“Child sleeps too little”, scoring criteria 2–4 or 5–7 days per week), and question 25 (“Child awakes more than once during the night”, scoring criteria 2–4 or 5–7 days per week). Each question contained a follow-up question about whether the parents experienced the question’s area as a problem (yes/no). If at least one of the questions met the scoring criteria and that the question’s area was perceived as a problem, the child was considered eligible for inclusion. More information regarding the recruitment process and the representativeness of the sample is described elsewhere [21].
Ethical approval was granted by the Swedish Ethical Review Authority (no. 2019–02158) adhering to guidelines set by the Declaration of Helsinki. Participation was voluntary and participants were informed of their right to withdraw without explanation. Oral and written information about the study was presented and, after receiving information, parents signed informed consents for themselves and on behalf of their children before entering the study.
A total of 154 children were considered eligible after diagnostics and screening had been performed. The parents and children were invited by telephone to participate in the research project, of whom 94 child-parent dyads (53 boys and 41 girls) accepted and consented to participate. In the current study, 83 (46 boys and 37 girls, aged 6–14) of the 88 children with parents who completed the 16-week intervention period were included (Fig. 1).
Fig. 1.
CONSORT flow diagram of the recruitment and patients enrolled in this study
Intervention and data collection
The sleep intervention with weighted blankets included a cross-over phase (4 + 4 weeks) and an open-label phase (8 weeks). The children were randomized into sleeping with a weighted blanket or a lighter control blanket for the first four weeks of the cross-over phase, and then a cross-over was performed of the weighted blanket group and control blanket group for the following four weeks. The children then slept during the open-label phase with either the weighted blanket or the lighter control blanket depending on which they preferred. The data collection was made through repeated measurements across four measurement weeks: baseline and weeks 4, 8, and 16. Sociodemographic data (age and gender of children, ADHD subtype, medication, use of stimulants, age and gender of parents, educational level, employment status and civil status) were gathered at baseline. The data utilized in this study consisted of the information collected at the 16-week follow-up.
Health-related measures
Children’s Sleep Habits Questionnaire – Swedish version (CSHQ-SWE)
Children’s Sleep Habits Questionnaire – Swedish version (CSHQ-SWE) [24] is a questionnaire completed by parents to describe their child’s sleep problems during the preceding week. It is a Swedish version of the English original [23] and has been validated in the target group [24]. The questionnaire consists of 33 items and the total score ranges from 33 to 99. The parents estimate the occurrence of sleep problems on questions 1–31 as “usually” (occurs 5 times or more during a week, 3 points), “sometimes” (occurs 2–4 times per week, 2 points) or “rarely” (occurs never or once a week, 1 point). For questions 32 and 33, sleepiness during various activities is estimated as “not sleepy” (1 point), “very sleepy” (2 points) and “falls asleep” (3 points) [23]. A higher total score indicates greater severity of sleep problems, and the cut-off for clinically relevant sleep problems for children with ADHD is ≥ 48 points [25]. The participants in this study were divided into two groups based on the classification criteria for children with ADHD [25] at the 16-week follow-up: those without clinically relevant sleep problems (CSHQ-SWE total score < 48 points) and those with clinically relevant sleep problems (CSHQ-SWE total score ≥ 48 points). Grouping was performed irrespective of the choice of a weighted blanket or a control blanket during the open-label phase, and irrespective of adherence to chosen blanket (Fig. 2).
Fig. 2.
CONSORT flow diagram of the participants in the analyses of this study
Insomnia Severity Index (ISI)
Insomnia Severity Index (ISI) is a seven item self-reported measure for children and adolescents used to evaluate insomnia. It covers difficulties falling asleep, maintaining sleep, early morning awakening, sleep satisfaction, interference with daily functioning, noticeability of sleep problems, and distress regarding sleeping problems. Each item is rated on a five-point Likert scale, with scores ranging from 0 to 4 and the total score is in the range 0–28. Higher scores on the ISI reflect increased severity [26]. The measure in this study was modified with regards to language to enhance applicability and comprehension among younger users, ensuring that it resonated with their developmental stage and cognitive abilities.
The short form of State-Trait Anxiety Inventory (short STAI)
The short form of State-Trait Anxiety Inventory (short STAI) is a six-item self-reported measure for children and adolescents for evaluating anxiety. The items Calm, Tense, Upset, Relaxed, Content, and Worried are each rated on a four-point Likert scale. The total score ranges from 6 to 24 points, with higher scores indicating higher anxiety levels [27, 28]. The short STAI is used when the full form is considered to be too comprehensive.
Child Outcome Rating Scale (CORS)
The self-reported Child Outcome Rating Scale (CORS) for children in the ages 6–12 years assesses life functioning across four domains including own well-being (How am I doing?), family (How are things in my family?), school (How am I doing at school?), and overall well-being (How is everything going?) on a visual analogue scale from 0 (worst, frowny face) to ten (best, happy face). In addition, it contains an overall total score, which ranges from 0 to 40 points (worst to best), with higher scores indicating better life functioning [29].
EQ-5D-Y-3 L
EQ-5D-Y-3 L is a five-item self-reported measure for children and adolescents used to evaluate health-related quality of life. The measure includes the following domains: mobility, looking after myself, doing usual activities, having pain or discomfort, and feeling worried, sad, or unhappy. Each domain is answered on a scale from 1 to 3, where 1 corresponds to no problems, 2 corresponds to some problems, and 3 indicates significant problems. Additionally, a visual analogue scale (VAS) was used. The VAS ranges from 0 to 100, reflecting overall health, with a higher score indicating better perceived health [30, 31].
The Swanson, Nolan, and Pelham Rating Scale – Parent-reported version (SNAP-IV parent)
SNAP-IV parent, which assesses symptoms of ADHD, comprises 18 items on a four-point Likert scale (ranging from 0 = ‘not at all’ to 3 = ‘very much’) to assess the severity of symptoms. Nine items cover attention deficit, six items hyperactivity, and three items impulsivity, yielding 0–27 points for attention deficit and for hyperactivity/impulsivity respectively. A combined measure yields 0–54 points. Higher scores indicate a heightened manifestation of ADHD symptoms [32].
Data analysis
The Shapiro Wilks test was used to analyse normal distribution of variables. Sociodemographic data and outcome measures (ISI, Short-STAI, CORS, EQ-5D-Y-3 L, EQ-5D-Y-3 L VAS, and SNAP-IV parent) were presented as means and standard deviations (SD), medians and interquartile ranges (IQR), or numbers and percentages. Due to limited distribution in answers, the response options of “some problems” and “significant problems” were merged and categorized as “problems” in EQ-5D-Y-3 L. Analyses between the groups with and without clinically relevant sleep problems were conducted by independent samples t-tests or by Mann-Whitney U tests, depending on normal distribution of data, and by Chi-square tests (Fisher’s exact test or Fisher-Freeman-Halton exact test where appropriate) for categorical variables. Effect sizes for independent samples t-tests were analysed with Cohen’s d (d = 0.20–0.49 representing small, d = 0.50–0.79 representing medium, and d ≥ 0.80 representing large [33] and for Mann-Whitney U tests with r (r < 0.3 representing small, r = 0.3–0.5 representing medium, and r > 0.5 representing large). IBM SPSS Statistics for Windows version 28 (IBM Corp, Armonk, New York, USA) were used and p-value was set to p < 0.05.
Results
The study consisted of 83 participants (45 boys and 38 girls; 6–14 years old). At the 16-week follow-up, 41 of these were grouped as being without parent-reported clinically relevant sleep problems (23 boys and 18 girls) and 42 were grouped as having parent-reported clinically relevant sleep problems (22 boys and 20 girls). There were no differences in sociodemographic factors between the two groups at baseline (Tables 1 and 2).
Table 1.
Comparisons of sociodemographic baseline factors for children between the groups at the 16-week follow-up
| No clinically relevant sleep problems, n = 41 | Clinically relevant sleep problems, n = 42 | U/t | z | p-value | |
|---|---|---|---|---|---|
| Children | |||||
| Age, mean ± SD | 9.54 ± 2.12 | 9.55 ± 2.43 | −0.022 | 0.982 | |
| Age, median (IQR) | 9.00 (8.00–11.00) | 9.50 (7.00–12.00) | 856.50 | −0.041 | 0.967 |
| Age, 6–9 years (%) | 22 (53.7) | 21 (50.0) | 0.827 | ||
| Age, 10–14 years (%) | 19 (46.3) | 21 (50.0) | |||
| Gender | |||||
| Male (%) | 23 (56.1) | 22 (52.4) | 0.827 | ||
| Female (%) | 18 (43.9) | 20 (47.6) | |||
| ADHD diagnosis | |||||
| Attention deficit (%) | 13 (31.7) | 10 (23.8) | 0.469a | ||
| Hyperactivity and impulsivity (%)/Combined (%) | 1 (2.4)/27 (65.9) | 1 (2.4)/31 (73.8) | |||
| Medication | |||||
| No medication (%) | 21 (51.2) | 24 (57.1) | 0.662 | ||
| Medication (%) | 20 (48.8) | 18 (42.9) | |||
| Stimulants | |||||
| No stimulants (%) | 23 (56.1) | 20 (47.6) | 0.512 | ||
| Stimulants (%) | 18 (43.9) | 22 (52.4) | |||
Results are expressed as means and SD, median and IQR, or number and percentage. Independent samples t-test and Mann-Whitney U test were used to analyse differences in children’s mean ages. Comparisons of children’s age groups, gender, ADHD diagnosis, medication, and use of central stimulants were conducted using Chi-square test or Fisher’s exact test
aAnalysed as attention deficit vs. hyperactivity, impulsivity and combined
ADHD, attention-deficit/hyperactivity disorder; IQR, interquartile range; SD, standard deviation
Table 2.
Comparisons of sociodemographic baseline factors for parents between the groups at the 16-week follow-up
| No clinically relevant sleep problems, n = 41 | Clinically relevant sleep problems, n = 42 | U/t | z | p-value | |
|---|---|---|---|---|---|
| Parents | |||||
| Age, mean ± SD | 39.41 ± 5.55 | 39.05 ± 5.50 | 0.303 | 0.763 | |
| Age, median (IQR) | 40.00 (35.50–42.00) | 38.00 (35.75–42.25) | 799.00 | −0.566 | 0.571 |
| Age 28–39 (%) | 20 (48.8) | 26 (61.9) | 0.273 | ||
| Age 40–52 (%) | 21 (51.2) | 16 (38.1) | |||
| Gender | |||||
| Male (%) | 5 (12.2) | 3 (7.1) | 0.483a | ||
| Female (%) | 36 (87.8) | 39 (92.9) | |||
| Educational level | |||||
| Elementary school (%) | 2 (4.9) | 4 (9.5) | 0.480b | ||
| High school (%) | 17 (41.5) | 13 (31.0) | |||
| University (%) | 22 (53.7) | 25 (59.5) | |||
| Employment c | |||||
| Employed (%) | 38 (92.7) | 34 (81.0) | 0.194 | ||
| Other (%) | 3 (7.3) | 8 (19.0) | |||
| Civil status | |||||
| Lives alone (%) | 5 (12.2) | 8 (19.0) | 0.548 | ||
| Lives with a partner (%) | 36 (87.8) | 34 (81.0) | |||
Results are expressed as means and SD, median and IQR, or number and percentage. Independent samples t-test and Mann-Whitney U test were used to analyse differences in parents’ mean ages. Comparisons of parents’ age groups, gender, educational level, employment status, and civil status were conducted using Chi-square test or Fisher's exact test
a Fisher’s exact test
b Fisher-Freeman-Halton exact test
c Employment was grouped as employed (full time or part time) or other (unemployment, parental leave, studying or sick leave)
IQR, interquartile range; SD, standard deviation
The children without clinically relevant sleep problems scored better in the analysis of ISI in terms of the variables falling asleep, satisfaction, and the total score compared to the group that had clinically relevant sleep problems. No group differences were observed in the remaining subscales (Table 3). The group without clinically relevant sleep problems scored better for the subscale tense in the Short-STAI, but none of the other variables revealed any differences between the groups (Table 3).
Table 3.
Comparisons of ISI and Short-STAI between the groups at the 16-week follow-up
| Median (IQR Q1–Q3) | U | z | p-value | Effect size r | ||
|---|---|---|---|---|---|---|
| No clinically relevant sleep problems, n = 41 | Clinically relevant sleep problems, n = 42 |
|||||
| ISI (Child-reported) | ||||||
| Falling asleep (0–4)a | 1.00 (1.00–1.50) | 1.50 (1.00–2.00) | 628.50 | −2.242 | 0.025 | −0.246 |
| Maintaining sleep (0–4)a | 0.00 (0.00–1.00) | 0.50 (0.00–1.00) | 837.50 | −0.237 | 0.812 | −0.026 |
| Early morning awakening (0–4)a | 0.00 (0.00–1.00) | 0.50 (0.00–2.00) | 718.00 | −1.461 | 0.144 | −0.160 |
| Satisfaction (0–4)a | 0.00 (0.00–1.00) | 1.00 (0.00–1.00) | 649.00 | −2.171 | 0.030 | −0.238 |
| Interference (0–4)a | 1.00 (0.00–2.00) | 1.00 (1.00–2.00) | 730.50 | −1.233 | 0.218 | −0.135 |
| Noticeability (0–4)a | 1.00 (0.00–2.00) | 1.00 (0.75–2.25) | 821.50 | −0.371 | 0.711 | −0.041 |
| Distress (0–4)a | 0.00 (0.00–1.00) | 0.50 (0.00–1.00) | 711.50 | −1.537 | 0.124 | −0.169 |
| Total score (0–28)a | 5.00 (3.00–8.00) | 7.50 (5.75–10.25) | 583.50 | −2.537 | 0.011 | −0.278 |
| Short-STAI (Child-reported) | ||||||
| Calm (1–4)a | 2.00 (1.00–2.00) | 2.00 (1.00–2.00) | 760.00 | −0.997 | 0.319 | −0.109 |
| Tense (1–4)a | 1.00 (1.00–2.00) | 2.00 (1.00–2.00) | 671.00 | −1.986 | 0.047 | −0.218 |
| Upset (1–4)a | 1.00 (1.00–2.00) | 1.00 (1.00–2.00) | 772.00 | −1.008 | 0.313 | −0.111 |
| Relaxed (1–4)a | 2.00 (1.00–2.00) | 2.00 (1.00–2.00) | 859.00 | −0.200 | 0.984 | −0.022 |
| Content (1–4)a | 2.00 (1.00–2.00) | 2.00 (1.00–2.00) | 722.00 | −1.431 | 0.152 | −0.157 |
| Worried (1–4)a | 1.00 (1.00–1.50) | 1.00 (1.00–2.00) | 816.00 | −0.532 | 0.594 | −0.058 |
| Total score (6–24)a | 9.00 (7.00–10.50) | 10:00 (8:00–12:00) | 718.50 | −1.309 | 0.191 | −0.144 |
Note: p-values of < 0.05 are marked in bold
Results were analysed with Mann-Whitney U test (effect size r) and presented as median and IQR
aTotal possible ranges for ISI and Short-STAI, scored best–worst
ISI, Insomnia Severity Index; IQR, interquartile range; Q, quartile; Short-STAI, The short form of State-Trait Anxiety Inventory
The findings from CORS indicated that there were no statistically significant differences between the two groups of children in the total score or in any of the sub domains (Table 4).
Table 4.
Comparisons of CORS between the groups at the 16-week follow-up
| Median (IQR Q1–Q3) | U | z | p-value | Effect size r | ||
|---|---|---|---|---|---|---|
| No clinically relevant sleep problems, n = 41 |
Clinically relevant sleep problems, n = 42 |
|||||
| CORS (Child-reported) | ||||||
| Me (0–10)a |
9.30 (7.60–10.00) |
8.10 (6.25–10.00) |
664.00 | −1.827 | 0.068 | −0.201 |
| Family (0–10)a |
10.00 (8.85–10.00) |
9.30 (7.53–10.00) |
718.00 | −1.370 | 0.171 | −0.150 |
| School (0–10)a |
8.50 (7.00–9.85) |
7.65 (5.25–9.45) |
739.00 | −1.116 | 0.265 | −0.122 |
| Everything (0–10)a |
9.10 (7.40–10.00) |
8.90 (6.98–10.00) |
729.50 | −1.220 | 0.223 | −0.134 |
| Total score (0–40)a |
36.00 (30.35–38.80) |
33.10 (27.78–36.45) |
665.50 | −1.782 | 0.075 | −0.196 |
Results were analysed with Mann-Whitney U test (effect size r) and presented as median and IQR
aTotal possible ranges for CORS, scored worst–best
CORS, Child Outcome Rating Scale; IQR, interquartile range; Q, quartile
The result of the five dimensions in the EQ-5D-Y-3 L showed no statistically significant results between the two groups of children (Table 5), and there were no statistically significant differences in perceived health observed in the EQ-5D-Y-3 L VAS (Table 6).
Table 5.
Comparison of EQ-5D-Y-3 L between the groups at the 16-week follow-up
| No clinically relevant sleep problems, n = 41 (%) | Clinically relevant sleep problems, n = 42 (%) | p-value | |
|---|---|---|---|
| EQ-5D-Y-3 L (Child-reported) | |||
| Mobility | |||
| No problems | 40 (97.6) | 40 (95.2) | 1.000a |
| Problemsb | 1 (2.4) | 2 (4.8) | |
| Looking after myself | |||
| No problems | 38 (92.7) | 32 (76.2) | 0.067 |
| Problemsb | 3 (7.3) | 10 (23.8) | |
| Doing usual activities | |||
| No problems | 38 (92.7) | 34 (81.0) | 0.194 |
| Problemsb | 3 (7.3) | 8 (19.0) | |
| Having pain or discomfort c | |||
| No problems | 35 (87.5) | 31 (73.8) | 0.165 |
| Problemsb | 5 (12.5) | 11 (26.2) | |
| Feeling worried, sad, or unhappy | |||
| No problems | 33 (80.5) | 28 (66.7) | 0.214 |
| Problemsb | 8 (19.5) | 14 (33.3) | |
Results were analysed with Chi-square test or Fisher’s exact test and presented as number and percentage
aFisher’s exact test
bOptions “some problems” and “significant problems” were merged and categorized as “problems”
COne person missing in domain from the group of no clinically relevant sleep problems
Table 6.
Comparisons of EQ-5D-Y-3 L VAS between the groups at the 16-week follow-up
| Median (IQR Q1–Q3) | U | z | p-value | Effect size r | ||
|---|---|---|---|---|---|---|
| No clinically relevant sleep problems, n = 41 |
Clinically relevant sleep problems, n = 42 |
|||||
| EQ-5D-Y-3 L (Child-reported) | ||||||
| VAS (0–100)a |
93.00 (80.00–100.00) |
89.50 (75.00–96.25) |
720.50 | −1.291 | 0.197 | −0.142 |
Results were analysed with Mann-Whitney U test (effect size r) and presented as median and IQR
aTotal possible range for EQ-5D-Y-3 L VAS, scored worst–best
IQR, interquartile range; Q, quartile; VAS, visual analogue scale
Analyses from SNAP-IV revealed that the group without clinically relevant sleep problems displayed a lower severity of attention deficit in comparison with the other group, as well as a lower severity of the combined score for attention deficit and hyperactivity/impulsivity (Table 7).
Table 7.
Comparisons of SNAP-IV parent between the groups at the 16-week follow-up
| No clinically relevant sleep problems, n = 41 |
Clinically relevant sleep problems, n = 42 |
t | p-value | Effect size Cohen’s d | |
|---|---|---|---|---|---|
| SNAP-IV (parent-reported) | |||||
| Total score attention deficit (0–27)a, mean ± SD | 13.24 ± 4.72 | 17.74 ± 4.88) | −4.265 | < 0.001 | −0.936 |
| Total score hyperactivity and impulsivity (0–27)a, mean ± SD | 12.20 ± 6.19 | 14.38 ± 6.22 | −1.605 | 0.112 | −0.352 |
| Total score combined (0–54)a, mean ± SD | 25.44 ± 9.93 | 32.12 ± 8.88 | −3.233 | 0.002 | −0.710 |
Note: p-values of < 0.05 are marked in bold
Results were analysed with independent samples t-test (Cohen’s d) and presented as mean, SD, and t- value
aTotal possible range for SNAP-IV, scored best–worst
ADHD, attention deficit hyperactivity disorder; SNAP-IV, The Swanson, Nolan, and Pelham Rating Scale; SD, standard deviation
Discussion
The principal findings of this study showed that, among children aged 6–14 years with ADHD, those without clinically relevant sleep problems after the sleep intervention reported significantly fewer insomnia symptoms and less tension compared to those who continued to have clinically relevant sleep problems. In addition, their parents rated the severity of attention deficit symptoms as lower. These results suggest that improvements in sleep are associated not only with better subjective sleep experiences but also with a reduced burden of ADHD symptoms as perceived by parents. However, no significant differences between the groups were found regarding self-reported life functioning or overall health-related quality of life, suggesting that broader aspects of daily functioning may be less directly influenced by sleep improvements in the short term.
The children with ADHD and without clinically relevant sleep problems tended to experience insomnia (as measured by ISI) to a lesser extent than children with ADHD and clinically relevant sleep problems. To the best of our knowledge, no studies have compared insomnia in children with ADHD based on the clinical cut-off by Parreira et al. [25], but Akinci et al. [2] found that children with ADHD, in comparison with controls without ADHD, reported more frequent problems with insomnia. Sciberras et al. [8] found five various sleep profiles in children with ADHD, with the insomnia profile being the most common, indicating that insomnia is a significant sleep problem in this group of children. More research is needed regarding insomnia and other sleep problems in children with ADHD and how the characteristics of sleep problems are conveyed in parent-reported instruments as well as in child-reported instruments.
The children without clinically relevant sleep problems in our study exhibited lower levels of the anxiety symptom ‘tension’ (as measured by short-STAI), while no significant differences were observed in other anxiety symptoms between the groups. In line with our results, Sciberras et al. [8] found that children with ADHD without sleep problems displayed anxiety symptoms to a lesser extent than children with ADHD in terms of the sleep profiles of insomnia, generalised sleep difficulties, and high bedtime resistance. Mayes et al. [34] demonstrated that children with ADHD, particularly those comorbid with anxiety or depression, often struggled with various sleep problems. The relationship between sleep problems and anxiety symptoms in children with ADHD warrants more research, particularly regarding how remission in sleep problems could potentially decrease anxiety levels.
There were no differences in life functioning (as measured by CORS) or health-related quality of life (as measured by EQ-5D-Y-3 L) between children without and with clinically relevant sleep problems in our study. This contradicts previous results presented by Sciberras et al. [8] where children with ADHD without sleep problems were reported to have fewer emotional problems than children with ADHD and sleep problems. Those results were, however, based on parental reports and not self-reported by the children, as in our study. Moreover, their assessment of emotional problems included similar aspects to those covered in our life functioning and health-related quality of life measures, but the questionnaires used were not the same. Yürümez & Kılıç [35]. assessed quality of life in children with ADHD (with and without sleep problems) and a control group of children without ADHD and found worse scores for quality of life for children with ADHD reported by both parents and children respectively. No analyses for quality of life were, however, performed between children with ADHD and with and without sleep problems. More studies are needed to elucidate the relationship between various levels of sleep problems, life functioning, and health-related quality of life in children with ADHD, as well as the accordance between self-reported and parental reported measures for these factors.
Parents of children without clinically relevant sleep problems in our study reported fewer ADHD symptoms (as measured by SNAP-IV) on the attention deficit scale compared to parents of children with clinically relevant sleep problems. This aligns with the findings of Sciberras et al. [8], who demonstrated that children with ADHD without sleep problems had fewer problems with ADHD symptoms compared to children with ADHD and sleep problems. Yin et al. [36] further highlights the relationship between increasing ADHD symptoms and increasing sleep problems. The findings from our study and from previous literature underscores the importance of considering sleep in the evaluation and management of ADHD symptoms in children, as sleep problems may exacerbate ADHD-related behaviour and impairments.
Taken together, these findings highlight the central role of sleep in the health of children with ADHD. While children without significant sleep problems reported better sleep and fewer ADHD symptoms, those who continued to struggle with sleep represent a vulnerable group in need of targeted interventions. Addressing sleep difficulties in children with ADHD may be an important pathway not only for improving sleep itself, but also for reducing ADHD symptom severity and supporting overall well-being.
Strengths and limitations
The study’s cross-sectional design allowed for a comprehensive overview of the participants’ health-related factors, aiding comparisons between different groups of children with ADHD, without or with clinically relevant sleep problems. The use of established cut-off criteria for clinically relevant sleep problems enhanced classification precision within the selected population. Thorough participant recruitment based on specific criteria ensured a homogeneous group, strengthening validity. Established measurement instruments facilitated multidimensional assessment, while robust data analysis ensured reliability. However, the limitations included the inability to capture temporal changes or establish causality with the current study design. There is a risk of Type II error and that differences that exist may have been missed due to the relatively small sample. Moreover, multiple independent comparisons were performed in our study, which increases the risk of false positive results, especially for p-values above 0.01. Reliance on subjective measurement instruments may have increased the risk of bias and the age differences might have affected the result. Where the data collection procedure is concerned, there seems to be a discrepancy between child-rated and parent-rated outcomes in terms of severity of sleep problems. For example, CSHQ is not validated for use in children older than 12 years [23, 24], which impacts on the concordance between parent and child-reported sleep. Sociodemographic and parental factors might affect the outcome and generalizability, however, the study has a relatively balanced sample which could improve the understanding of the relationship between sleep problems and health variables in this population. Another limitation is that restless legs syndrome and sleep disordered breathing that in previous studies have shown associations with ADHD were not assessed in the current study.
Conclusions
Our study highlights a potential link between a lower level of self-reported insomnia and of the anxiety symptom ‘tension,’ and fewer parent-reported ADHD symptoms for attention deficit in children with ADHD without clinically relevant sleep problems compared to their counterparts with clinically relevant sleep problems. No differences in self-reported life functioning and health-related quality of life were found between children without and with clinically relevant sleep problems. Our findings indicate that better sleep in children with ADHD improves their well-being and ADHD-related symptoms which may affect their overall health. Since better sleep has the potential to reduce ADHD symptoms, an increased focus on sleep when meeting children with ADHD may be of value. These results may be used in clinical practice to promote a holistic approach regarding management of sleep problems in children with ADHD. These findings require validation in larger groups of children with ADHD and various levels of sleep problems. Furthermore, longitudinal studies are necessary to fully comprehend the long-term impact of sleep problems and various health-related factors in this cohort. Investigations of long-term effects following targeted interventions are also of importance.
Acknowledgements
We thank Maria Lönn for help with data collection, Katarina Aili for help with planning the study, the staff at the Child and Adolescent Mental Health Service, and the children and their parents.
Abbreviations
- ADHD
Attention-Deficit/Hyperactivity Disorder
- CAMHS
Child and Adolescent Mental Health Service
- CORS
The Child Outcome Rating Scale
- CSHQ
Children’s Sleep Habits Questionnaire
- CSHQ-SWE
Swedish version of the Children’s Sleep Habits Questionnaire
- IQR
Interquartile range
- ISI
The Insomnia Severity Index
- Q
Quartile
- SD
Standard deviation
- Short-STAI
The short form of State-Trait Anxiety Inventory
- SNAP-IV
The Swanson, Nolan, and Pelham Rating Scale
Author contributions
Conception and design of the work: JSM, PS, JN, HJ, and IL; Acquisition of data: IL; Analysis of data: AL, JSM, and JT; Interpretation of data: PS, JN, HJ, and IL; Drafted the work: AL, JSM, and JT; Substantively revised the work: PS, JN, HJ, and IL. All authors read and approved the final manuscript. All authors also agreed to be fully accountable for the accuracy and integrity of the work.
Funding
Open access funding provided by Halmstad University. The funders for the study are the Knowledge Foundation [grant number 20200012 and grant number 20180185] and the Swedish Research Council for Health, Working Life and Welfare (Forte, Forskningsrådet för hälsa, arbetsliv och välfärd) [grant number 2021 − 00664]. The funders were not involved in study design, collection, analysis, interpretation of data, writing, or submission for publication.
Data availability
The datasets generated during and/or analyzed during the current study are not publicly available due to legal/ethical reasons but are available from the corresponding author on reasonable request.
Declarations
Ethics approval and consent to participate
Ethical approval was granted by the Swedish Ethical Review Authority (no. 2019–02158) adhering to guidelines set by the Declaration of Helsinki. Participation was voluntary and participants were informed of their right to withdraw without explanation. Oral and written information about the study was presented and, after receiving information, parents signed informed consents for themselves and on behalf of their children before entering the study.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.American Psychological Association. Diagnostic and statistical manual of mental disorders: DSM-5. Arlington, Va.: American Psychological Association; 2013. [Google Scholar]
- 2.Akinci G, Oztura I, Hiz S, Akdogan O, Karaarslan D, Ozek H, Akay A. Sleep structure in children with attention-deficit/hyperactivity disorder. J Child Neurol. 2015;30(11):1520–5. [DOI] [PubMed] [Google Scholar]
- 3.Corkum P, Tannock R, Moldofsky H, Hogg-Johnson S, Humphries T. Actigraphy and parental ratings of sleep in children with attention-deficit/hyperactivity disorder (ADHD). Sleep. 2001;24(3):303–12. [DOI] [PubMed] [Google Scholar]
- 4.Sung V, Hiscock H, Sciberras E, Efron D. Sleep problems in children with attention-deficit/hyperactivity disorder: prevalence and the effect on the child and family. Arch Pediatr Adolesc Med. 2008;162(4):336–42. [DOI] [PubMed] [Google Scholar]
- 5.Efron D, Lycett K, Sciberras E. Use of sleep medication in children with ADHD. Sleep Med. 2014;15(4):472–5. [DOI] [PubMed] [Google Scholar]
- 6.Quach J, Hiscock H, Wake M. Sleep problems and mental health in primary school new entrants: cross-sectional community-based study. J Paediatr Child Health. 2012;48(12):1076–81. [DOI] [PubMed] [Google Scholar]
- 7.Bathory E, Tomopoulos S. Sleep regulation, physiology and development, sleep duration and patterns, and sleep hygiene in infants, toddlers, and preschool-age children. Curr Probl Pediatr Adolesc Health Care. 2017;47(2):29–42. [DOI] [PubMed] [Google Scholar]
- 8.Sciberras E, Hiscock H, Cortese S, Becker SP, Fernando JW, Mulraney M. Variation in sleep profiles in children with ADHD and associated clinical characteristics. J Child Psychol Psychiatry. 2023;64(10):1462–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Miano S, Parisi P, Villa MP. The sleep phenotypes of attention deficit hyperactivity disorder: the role of arousal during sleep and implications for treatment. Med Hypotheses. 2012;79(2):147–53. [DOI] [PubMed] [Google Scholar]
- 10.Migueis DP, Lopes MC, Casella E, Soares PV, Soster L, Spruyt K. Attention deficit hyperactivity disorder and restless leg syndrome across the lifespan: a systematic review and meta-analysis. Sleep Med Rev. 2023;69: 101770. [DOI] [PubMed] [Google Scholar]
- 11.Gossard TR, Trotti LM, Videnovic A, St Louis EK. Restless legs syndrome: contemporary diagnosis and treatment. Neurotherapeutics. 2021;18(1):140–55. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Langberg JM, Molitor SJ, Oddo LE, Eadeh HM, Dvorsky MR, Becker SP. Prevalence, patterns, and predictors of sleep problems and daytime sleepiness in young adolescents with ADHD. J Atten Disord. 2020;24(4):509–23. [DOI] [PubMed] [Google Scholar]
- 13.Craig SG, Weiss MD, Hudec KL, Gibbins C. The functional impact of sleep disorders in children with ADHD. J Atten Disord. 2020;24(4):499–508. [DOI] [PubMed] [Google Scholar]
- 14.Becker SP, Cusick CN, Sidol CA, Epstein JN, Tamm L. The impact of comorbid mental health symptoms and sex on sleep functioning in children with ADHD. Eur Child Adolesc Psychiatry. 2018;27(3):353–65. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Eyuboglu M, Eyuboglu D. Behavioural sleep problems in previously untreated children with attention deficit hyperactivity disorder. Psychiatry Clin Psychopharmacol. 2018;28(1):19–24. [Google Scholar]
- 16.Langberg JM, Molitor SJ, Oddo LE, Eadeh H-M, Dvorsky MR, Becker SP. Prevalence, Patterns, and Predictors of Sleep Problems and Daytime Sleepiness in Young Adolescents with Attention-Deficit/Hyperactivity Disorder. Grantee Submission 2017. [DOI] [PubMed]
- 17.Meltzer LJ, Wainer A, Engstrom E, Pepa L, Mindell JA. Seeing the whole elephant: a scoping review of behavioral treatments for pediatric insomnia. Sleep Med Rev. 2021;56: 101410. [DOI] [PubMed] [Google Scholar]
- 18.Vigliano P, Galloni GB, Bagnasco I, Delia G, Moletto A, Mana M, Cortese S. Sleep in children with attention-deficit/hyperactivity disorder (ADHD) before and after 6-month treatment with methylphenidate: a pilot study. Eur J Pediatr. 2016;175(5):695–704. [DOI] [PubMed] [Google Scholar]
- 19.Lönn M, Svedberg P, Nygren J, Jarbin H, Aili K, Larsson I. The efficacy of weighted blankets for sleep in children with attention-deficit/hyperactivity disorder—a randomized controlled crossover trial. J Sleep Res. 2024;33(2): e13990. [DOI] [PubMed] [Google Scholar]
- 20.Becker SP, Langberg JM, Eadeh HM, Isaacson PA, Bourchtein E. Sleep and daytime sleepiness in adolescents with and without ADHD: differences across ratings, daily diary, and actigraphy. J Child Psychol Psychiatry. 2019;60(9):1021–31. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Larsson I, Aili K, Nygren JM, Johansson P, Jarbin H, Svedberg P. Sleep: intervention with weighted blankets for children with attention deficit hyperactivity disorder (ADHD) and sleep problems: study protocol for a randomised control trial. BMJ Open. 2022;12(1): e047509. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Wernersson R, Johansson J, Andersson M, Jarbin H. Evaluation of a new model for assessment and treatment of uncomplicated ADHD - effect, patient satisfaction and costs. Nord J Psychiatry. 2020;74(2):96–104. [DOI] [PubMed] [Google Scholar]
- 23.Owens JA, Spirito A, McGuinn M. The children’s sleep habits questionnaire (CSHQ): psychometric properties of a survey instrument for school-aged children. Sleep. 2000;23(8):1043–51. [PubMed] [Google Scholar]
- 24.Larsson I, Svedberg P, Nygren JM, Malmborg JS. Validity and reliability of the Swedish version of the children’s sleep habits questionnaire (CSHQ-SWE). BMC Pediatr. 2024;24(1):378. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Parreira AF, Martins A, Ribeiro F, Silva FG. Validação Clínica da Versão Portuguesa do Questionário de Hábitos de Sono das Crianças (CSHQ-PT) em Crianças com Perturbações do Sono e PHDA. Acta Med Port. 2019;32(3):195–201. [DOI] [PubMed] [Google Scholar]
- 26.Bastien CH, Vallières A, Morin CM. Validation of the insomnia severity index as an outcome measure for insomnia research. Sleep Med. 2001;2(4):297–307. [DOI] [PubMed] [Google Scholar]
- 27.Nilsson S, Buchholz M, Thunberg G. Assessing children’s anxiety using the modified short State-Trait anxiety inventory and talking mats: A pilot study. Nurs Res Pract. 2012;2012:932570. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Spielberger CD. State-trait anxiety inventory for Children:(how I Feel Questionnaire). Consulting Psychologists; 1973.
- 29.Duncan BL, Sparks Jacqueline A, Miller SD, Bohanske RT, Claud DA. Giving youth a voice: a preliminary study of the reliability and validity of a brief outcome measure for children, adolescents, and caretakers. J Brief Ther. 2006;5(2):71–88. [Google Scholar]
- 30.Burstrom K, Bartonek A, Brostrom EW, Sun S, Egmar AC. EQ-5D-Y as a health-related quality of life measure in children and adolescents with functional disability in sweden: testing feasibility and validity. Acta Paediatr (Oslo Norway: 1992). 2014;103(4):426–35. [DOI] [PubMed] [Google Scholar]
- 31.Wille N, Badia X, Bonsel G, Burstrom K, Cavrini G, Devlin N, Egmar AC, Greiner W, Gusi N, Herdman M, et al. Development of the EQ-5D-Y: a child-friendly version of the EQ-5D. Qual Life Res. 2010;19(6):875–86. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Bussing R, Fernandez M, Harwood M, Wei H, Garvan CW, Eyberg SM, Swanson JM. Parent and teacher SNAP-IV ratings of attention deficit hyperactivity disorder symptoms: psychometric properties and normative ratings from a school district sample. Assess. 2008;15(3):317–28. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. Hillsdale, NJ: Lawrence Erlbaum Associates,; 1988. [Google Scholar]
- 34.Mayes SD, Calhoun SL, Bixler EO, Vgontzas AN, Mahr F, Hillwig-Garcia J, Elamir B, Edhere-Ekezie L, Parvin M. ADHD subtypes and comorbid anxiety, depression, and oppositional-defiant disorder: differences in sleep problems. J Pediatr Psychol. 2009;34(3):328–37. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Yürümez E, Kılıç BG. Relationship between sleep problems and quality of life in children with ADHD. J Atten Disord. 2016;20(1):34–40. [DOI] [PubMed] [Google Scholar]
- 36.Yin H, Yang D, Yang L, Wu G. Relationship between sleep disorders and attention-deficit-hyperactivity disorder in children. Front Pediatr. 2022;10: 919572. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets generated during and/or analyzed during the current study are not publicly available due to legal/ethical reasons but are available from the corresponding author on reasonable request.