Background

Healthy sleep is essential for growing, development, and mental and physical health. However, insomnia and insomnia symptoms are not only observed in adults, they are also common in children and have various effects on wellbeing. Prevalence varies widely depending on the measure used for diagnosis. In young children, rates have been reported between 2.5 and 16.6% [10, 46], in primary school children between 8.3 and 21.2% [7, 10, 46], and in adolescents between 7.9 and 36% [7, 10], demonstrating an increase in the maximum range with increasing age.

Insomnia duration and chronicity

The risk of chronicity of insomnia symptoms and disorder has already been reported for adults [21, 22, 29]. Several studies have shown that patients with an insomnia diagnosis have a higher risk for chronic insomnia as compared to patients with insomnia symptoms only [21, 29]. Different theoretical models for insomnia point toward cognitive activity, cognitive arousal, distress, sleep perception, and circadian rhythms (among others) as potential factors maintaining and worsening insomnia symptoms, which may, in turn, lead to chronic insomnia [5, 15].

Not much is known about insomnia chronicity in children. Insomnia symptoms, such as problems initiating and maintaining sleep or poor sleep quality, tend to be stable over time [1, 8, 11, 28, 42]. However, only few studies used criteria for insomnia diagnoses according to the second or third edition of the International Classification of Sleep Disorders (ICSD-II/ICSD-3), the fourth or fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV/DSM-5), or the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) to examine insomnia chronification over several years in children (e.g., [7, 10, 46]). Steinsbekk and Wichstrøm [46] found untreated insomnia to be stable in 43% of their study participants (aged 4 years at first assessment) over the course of 2 years. In a 7-year longitudinal cohort study (194 children, mean age at first assessment: 8.7 years), 7% of children had persistent insomnia according to ICSD‑II criteria after 7 years [7]. A Norwegian longitudinal study (N = 1037) assessed insomnia (according to DSM‑IV and DSM-5) stability over the course of 10 years [10]. They found existing insomnia to be stable from one measurement to the following measurement in 32 to 40% of children and a 5- to 15-times higher probability of continuing insomnia as compared to children without insomnia [10]. In a cross-sectional study with 42 children aged 7 to 13 years, Paine and Gradisar [28] found a mean age of insomnia onset of 3.7 years and a mean duration of the latest insomnia period of 5.7 years. This early onset was confirmed by Schlarb and colleagues [34], with an age for insomnia onset (N = 112, children 5 to 11.5 years) of 3.3 years.

These studies demonstrate that insomnia starts early, has a high likelihood to become chronic, and is stable over time when not treated properly. To conclude, children with insomnia and insomnia symptoms are at risk of chronic insomnia.

Insomnia and mental health

Insomnia and insomnia symptoms negatively influence several aspects of daily life and functioning in children, such as reduced psychosocial functioning and quality of life [13, 30, 31, 40], reduced emotion processing and emotion regulation [3, 20, 45], and these children have an increased probability of comorbid psychological disorders [8, 12, 14].

Insomnia and insomnia symptoms during childhood are related to increased anxiety [8, 9, 12, 39], significantly predict adult anxiety and depression disorders [9, 12, 39, 43, 49], and are related to aggressive behavior [41, 50]. With age, these psychological disorders also affect sleep behavior and may cause insomnia [39].

Recognition and severity of sleep impairment and help-seeking behavior

Problem awareness is a necessary, but not very present prerequisite for help-seeking behavior [24], i.e., parents need to recognize that their child has a sleep problem [25] and that it affects the child’s health [27, 33, 37]. One study even found that parents of children with a sleep disorder know less about sleep and sleep difficulties in children than parents with children without a sleep problem [18]. Parents do not report sleep problems to their general practitioner or pediatrician [4, 36, 44]. Not only parents but also professionals fail to identify sleep problems in children and adolescents [4, 26, 36]. However, recognizing the problem is mandatory for seeking help [25], and parents become less concerned and active with increasing age of their children [6, 23, 47, 48]. Parents’ help-seeking behavior is essential for treating insomnia in children, but little is known about its determinants.

Therefore, the present study assessed (1) the duration and severity of insomnia in a clinical sample of children aged 4–11 years, (2) whether children with an additional mental disorder have a longer insomnia duration and more severe sleep problems as compared to children without comorbid mental disorders, (3) how many self-help and professional help treatment efforts had been undertaken by the families, and (4) whether there is an association between help-seeking behavior and insomnia duration and severity.

Methods

Procedure

Families who presented at the authors’ outpatient clinics for insomnia in Bielefeld, Tübingen, and Würzburg were included. All families completed a broad sleep-related diagnostic process, including various questionnaires about sleep and sleep problems, general demographic data, general wellbeing, and a clinical interview assessing the children’s sleep problems. All participating families were informed about the goal, content, and procedure of the study, and gave informed consent. They were informed that they could quit the study at any time without negative consequences. Herein, data of the first assessment only are reported (longitudinal data are reported elsewhere). The study was approved by the institutional ethical review boards of the respective universities.

Measurements

Family registration form

The patient registration form assessed general information about the child (age, sex, mental and other health issues), socioeconomic information (parent education, siblings), and information about the child’s sleep and sleep-related behavior (sleep initiation, sleep maintenance, daytime functioning). Additionally, duration and severity of the current sleep problem of the child and the number of past treatment efforts were assessed. Sleep problem severity was determined by parental rating on a 10-point Likert scale with 1 = completely normal to 10 = very problematic. Past treatment efforts were quantified with two open questions about possible self-help efforts and seeking professional help. Parental answers about the type of help were sorted into categories (Table 1). Multiple responses were possible. When parents reported more than one help effort which could be assigned into one category, especially for the other categories, the category was counted only once.

Table 1 Overview of categories for self-help strategies and professional help
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Diagnostic interview for sleep disturbances

A self-developed parental diagnostic interview was conducted, assessing ICSD‑3 criteria for chronic insomnia [34, 38]. Exemplary questions were 1) “During the past 4 weeks, did your child have problems initiating sleep? How many minutes did your child need to fall asleep?”; 2) “During the past 4 weeks, did your child wake up during the night and if so, how often per week?” Answers were coded as follows: ? = not enough information provided by the parents to evaluate the answer; 1 = criterion not met; 2 = criterion not fully met; 3 = criterion met. The interview assessed insomnia criteria in detail and included screening questions for symptoms of other sleep disturbances, e.g., narcolepsy (“Has your child been extremely tired during the day on a nearly daily basis for at least 3 months? Is he or she so tired, that he or she falls asleep every now and then during the day?”), sleep-related breathing disorders (“Does your child snore during the night?”), and parasomnias (“Does your child suffer from nightmares? How often?”). Children presenting with symptoms of organic sleep disorders were referred to their pediatrician for further examination.

Sample

A total of N = 175 children (4–11 years, mean [M] = 7.62 years, standard deviation [SD] = 1.79; 48.6% girls) were included. With both parents lived n = 151 (86.3%) children, with a single parent n = 3 (1.7%), with one parent and new partner n = 16 (9.1%), and with adoptive or foster parents n = 4 (2.3%). For one child, no specific information about living conditions was available; n = 41 (23.4%) children attended kindergarten. The number of siblings varied between 0 and 8, with n = 35 (20.0%) children being the only child, most children having one sibling (n = 99; 56.6%), n = 36 (20.6%) children two siblings, and n = 5 (4.0%) three or more siblings. The mean age of mothers was 39.05 (SD = 4.82) years and of fathers 40.98 (SD = 5.57) years. For two fathers, no information about age was available.

Analyses

All data were analyzed with IBM SPSS Statistics 25 (IBM Corp., Armonk, NY, USA; [17]). Normal distribution was tested with Shapiro–Wilk test. Data were not normally distributed for all variables. Mann–Whitney U test was, thus, used for group comparisons, and Kendall’s tau as a correlation coefficient. To maintain a sample size as big as possible, children with missing data on insomnia severity only (n = 28) were included to maintain a high sample size. This led to different sample sizes throughout the results section. Significance level was set at α = 0.05.

Children with one or more mental disorder beside insomnia were categorized into the insomnia plus mental disorder group (I-MD), whereas children with insomnia but no other mental disorder were classified as insomnia without other mental disorder (I-NOMD).

Results

Insomnia duration and severity

Average childhood insomnia duration was 53.95 months (SD = 35.14 months), i.e., 4 years and 6 months. Mean age of insomnia onset was 37.49 months. Children younger than 11 years of age had spent half or more of their lifetime with insomnia or insomnia symptoms (Table 2).

Table 2 Insomnia duration in months and proportion of lifetime
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Insomnia severity was rated as high (M = 7.99, SD = 1.49) by parents (Table 3).

Table 3 Insomnia severity rated by parents
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Insomnia duration and severity in children with and without additional mental disorders

Most of the children, n = 112 (64%), had no other mental disorder; n = 48 (27.4%) had one, n = 12 (6.9%) had two, and n = 3 (1.7%) had three additional mental disorders. Albeit descriptively, insomnia severity (I-NOMD: mR (mean Rank of Mann-Whitney U test for group comparisons) = 72.87; I‑MD: mR = 75.95; U = 3,676.50, p = 0.644) was lower and duration (I-NOMD: mR = 86.67; I‑MD: mR = 90.36; U = 2,616.50, p = 0.663) shorter in the I‑NOMD group; neither of the two ratings differed between the groups (Tables 1 and 2).

Since no significant between-group differences were found for insomnia duration and severity, the following calculations were conducted for the whole sample.

Help-seeking behavior—number of self-help and professional help treatment efforts

Most of the parents (88.6%) reported self-help efforts and two thirds (66.9%) had tried to receive professional help prior to their contact with the insomnia outpatient clinic. The number of self-help efforts varied between 0 and 11 (M = 2.88, SD = 2.29), and that of seeking professional help between 0 and 8 (M = 1.25, SD = 1.40).

Parental answers showed a wide variety in the self-help strategies tried out. The main self-help strategy was changing parenting behavior (n = 84), followed by changing the bedtime ritual (n = 57), and changes in sleeping place (n = 37). See Fig. 1 for an overview of the distribution of self-help strategy categories.

Fig. 1
figure 1

Parental answers clustered in categories for the kind of self-help. Multiple answers were possible. Clusters are sorted in descending order, not in the cluster order named in the text

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The reported parental professional help-seeking showed less variability. The main professional help-seeking strategy reported by parents was consulting a pediatrician (n = 84), followed by a clear margin by consulting a counseling center (n = 24) and a psychologist (n = 13). Almost a quarter of parents also reported efforts in the category “other assistance” (n = 41), including osteopathy, homeopathy, and others. See Fig. 2 for an overview of the distribution of professional help-seeking strategy categories.

Fig. 2
figure 2

Parental answers clustered in categories for the kind of professional help. Multiple answers were possible. Clusters are sorted in descending order, not in the cluster order named in the text

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Relationship between self-help, professional help, insomnia duration, and insomnia severity

Insomnia severity rating was significantly correlated with the number of efforts at seeking professional help (τ = 0.199; p = 0.003) but not with the number of self-help efforts (τ = 0.035; p = 0.591). Neither the number of self-help efforts (τ = −0.034; p = 0.533) nor the number of seeking professional help efforts (τ = 0.083; p = 0.151) were significantly correlated with insomnia duration. However, most importantly, insomnia severity, but not insomnia duration, seems to be associated with seeking professional help. The number of self-help and professional help seeking efforts were significantly correlated (τ = 0.124; p = 0.042).

Discussion

The present study assessed insomnia duration and severity, differences in insomnia duration and severity measures between children with and without additional mental disorders, and parental help-seeking behavior related to children’s sleep problems in 175 children and their parents.

Insomnia duration and severity

The mean age of insomnia onset of 3.1 years in our sample and a duration of around 58% of the children’s lifetime is in line with the results of Paine & Gradisar [28] and Schlarb and colleagues [34]. With the extended lifetime duration of insomnia or insomnia symptoms, our study confirms the sparse literature about insomnia chronicity [7, 10, 46] and adds to the growing evidence that insomnia is highly likely to become chronic if not appropriately treated.

Beside insomnia duration, parental perception of the severity of their child’s sleep problem is important. Based on the model of parental attributional processes by Morrissey-Kane and Prinz [24], parental perception of the severity of a problem in child behavior can be seen as an indicator for parental help-seeking. Thus, families seek help if the child’s behavior impairs the intra-familial interactions. The present data support this assumption, as insomnia severity but not duration was an indicator of the amount and type of help-seeking behavior of parents [25].

In contrast to several other studies, herein, no differences in insomnia symptoms between children with or without comorbid psychological disorders were found. Van Dyk and colleagues [49] found attention deficit hyperactivity disorder (ADHD) and affective problems in preschool children and conduct and anxiety symptoms in primary school children to be associated with insomnia severity. Another study [8] found the number and duration of sleep problems (from infancy to the age of 10 years) to be associated with mental health measures (e.g., anxiety). A possible reason for our results may be that the current study reports cross-sectional but no longitudinal data. Another possible reason may be the different “labels” for insomnia, ranging from number of insomnia symptoms [8] up to the full assessment of the ICSD insomnia criteria ([49], current study), and likewise for the “diagnosis” of a psychological disorder. The use of different measures for diagnosis renders a comparison between studies difficult and the authors recommend using the ICSD and DSM‑5 criteria.

Taking these results together, the implementation of a stepped care model (SCM), as introduced by Baglioni and colleagues of the Steering Committee of the European Academy of Cognitive Behavioural Therapy for Insomnia [2] seems reasonable. The SCM is a process description of therapeutics based on cognitive behavioral therapy for insomnia (CBT-I) gradually increasing in clinical intensity and clinical complexity (for a detailed information, see [2]). However, to the best of the authors’ knowledge, no studies have proved the SCM for insomnia in children. Beside this lack of research, for adolescents, one study examined internet-delivered CBT‑I as an addition to the mental disorder treatment [51]. Promising preliminary results (significant reduction in insomnia symptoms and improvement in mental disorder measures) were found. Positive and stable effects of CBT‑I on insomnia measures and comorbid psychological disorders were also found for adult samples (for a review, see [16]). Consequently, implementation of the SCM and related promotion of knowledge about insomnia should be forced and further investigated.

Insomnia duration, insomnia severity, and help-seeking behavior

As in the few previous studies, most parents in the current study reported self-help efforts and two thirds reported seeking professional help, mainly consulting their pediatrician or a counselling center [6, 23, 25, 47, 48]. As the present results show, most parents have good self-help approaches to improve their child’s insomnia symptoms. It seems that professional mentoring is necessary to successfully implement these approaches and to adapt them to each child. In the present study, neither self-help nor professional help-seeking behavior were associated with insomnia duration. However, and very importantly, insomnia severity was significantly associated with professional help-seeking behavior of parents, confirming the results of Chung, Kan, and Yeung [6] in an adolescent sample, and of Newton and colleagues [25] for a sample of toddlers and children. In our study, searching for help at their pediatrician was by far the most given answer for searching for professional help. This can be seen as evidence of an outstanding need for specialized sleep trainings (diagnostic and therapeutic) for pediatricians, but also for other professionals like psychotherapists, physicians, medical health staff, and other medical health providers, in order to reduce the impact of sleep problems on children and their families. It was further found that the number of self-help efforts and efforts at seeking professional help were significantly associated, indicating the persistence of parents in help-seeking, and also that those who do not seek help likewise persist in their behavior—a result that was also reported by Kanis and colleagues [18].

Limitations

One major limitation is the cross-sectional character of the study. Hence, no causality assertion can be made regarding possible causes and influencing factors of insomnia development, duration, and differences in severity over time. For causality statements, longitudinal studies are necessary. Another limitation is the use of subjective measurements and the retrospective collection of insomnia duration measures. However, sleep disorders such as insomnia were assessed and diagnosed based on a multi-methodological diagnostic procedure including a structured clinical interview. The current study used medical consultation results from the children’s general practitioner or pediatrician to get information about other medical and psychological diseases. Given the lack of knowledge about sleep and sleep disorders among general practitioners and pediatricians [4, 26, 36], this source of information needs to be handled with care.

Conclusion

To further elucidate the chronification of insomnia and its effects on children’s psychological development, longitudinal studies (ideally a birth cohort) are necessary that include the parents’ help-seeking behavior. The SCM could considerably reduce the psychological strain of insomnia patients and improve the availability of insomnia therapy for patients in need by providing a patient-appropriate insomnia treatment [2]. There are several highly effective short-term treatments for insomnia available for all age groups from infancy to late adolescence [19, 32, 34, 35, 38], which also show that successfully treated sleep problems have a positive influence on general wellbeing.

By establishment in practice and by more research effort into a stepped care treatment (SCM) [2] for adequate and age-oriented help for insomnia disorder, the following aspects could be included: a) how to promote more awareness for healthy sleep during the whole lifespan for families and also for professionals, and b) how to establish a sleep help network based on profound research results.

Education of parents towards more knowledge about sleep behavior and disorders may be essential for families to be able to seek an early intervention.