Association between early childhood sleep difficulties and subsequent psychiatric illness

Abstract

Study Objectives:

Chronic disruptions to sleep in childhood are associated with increased prevalence of psychiatric disease later in development. When sleep disruptions remit before adolescence, the increased prevalence of psychiatric disease is no longer observed, highlighting the importance of early detection and intervention. Clinicians typically rely on caregivers’ reports for diagnosis and management of childhood sleep challenges. We examined whether findings on polysomnogram (PSG) can offer similar insight into childhood sleep difficulties and the risk of subsequent psychiatric illness.

Methods:

A cohort was identified of 348 children ages 5 years 11 months and younger with sleep difficulties rising to the level of formal clinical workup. A retrospective review of caregiver-reported sleep concerns, PSG results, and subsequent psychiatric illness was completed. PSG findings were compared to presence of psychiatric illness later in life as well as caregivers’ reported concerns. Chi-squared and Fisher’s exact tests were completed to evaluate correlations and Cohen’s kappa was used to evaluate agreement.

Results:

With only a few exceptions, comparisons between clinician findings on PSG and subsequent psychiatric diagnoses were statistically nonsignificant. Similarly, the relationship between caregivers’ subjective reports about sleep and clinicians’ findings on PSG demonstrated only slight to fair agreement, suggesting reported concerns were not predictive of PSG results.

Conclusions:

Parental reports of subjective sleep concerns are indicative of different sleep pathologies compared to sleep pathologies detected on PSG. The addition of PSG to caregiver-reported data appears to have limited clinical utility in understanding sleep concerns associated with the risk of subsequent psychiatric illness in young children.

Citation:

Pease E, Shekunov J, Savitz ST, et al. Association between early childhood sleep difficulties and subsequent psychiatric illness. J Clin Sleep Med. 2023;19(12):2059–2063.

BRIEF SUMMARY

Current Knowledge/Study Rationale: Caregivers’ reports of sleep difficulties in children have been associated with subsequent development of psychiatric illness later in life. We aimed to explore whether polysomnogram data could offer similar insights.

Study Impact: Polysomnogram is important to rule out underlying sleep pathology in children but overall does not appear to elicit data associated with subsequent psychiatric illness. The combination of polysomnogram and parent/caregiver reporting is important to fully conceptualize pediatric sleep difficulties.

INTRODUCTION

Sleep problems can be a normal aspect of early development; however, chronic disruptions to sleep can serve as an indicator of future emotional and/or behavioral difficulties later in childhood and into adulthood.¹ Prevalence of sleep disorders in a cohort of preschoolers found the total sleep disorder rate to be 19.2%, with primary insomnia being the most common disturbance.² Sleep plays a critical role in neurocognitive development and functioning. Children with adequate sleep time have greater advancement in their executive functioning. Sleep deprivation has been associated with higher emotional lability scores, increased prevalence of conduct-related behaviors, and elevated symptoms of attention-deficit/hyperactivity disorder including hyperactivity, poorer concentration, limitations with attention, impulsivity, irritability, and lower academic performance.³ Sleep disturbances—including decreased sleep duration, later sleep timing preference, longer sleep latency, frequent nighttime awakenings, and increased daytime sleepiness—have also been associated with elevated psychiatric symptom severity in children across multiple psychiatric diagnoses including bipolar disorder, depression, mood lability, anxiety, and externalizing symptoms.⁴ Although limited by study design, a bidirectional relationship has previously been observed between sleep and some psychiatric symptoms^5,6 such as hyperactivity and inattention or depression. However, the link between sleep difficulties in childhood and subsequent psychiatric symptoms has been well-established, noting that insufficient sleep contributes to emotional and behavioral symptoms as well as increased risk of psychiatric comorbidities.⁵ The relationship between sleep disturbances and subsequent psychiatric symptoms is present independent of other factors, including developmental disorders.⁷

Proposed mechanisms linking sleep difficulties and development of psychiatric symptoms include disrupted functioning within the cholinergic, serotonergic, and GABAergic pathways, which play integral roles in sleep and in anxiety and depressive disorders. Early disruptions in these systems could contribute to impaired regulation of sleep during childhood which, if persistent, may affect mood regulatory systems, increasing the risk of anxiety and depression. An additional theory linking sleep and mental health symptoms includes sleep-related breathing disorders leading to increased stress or inflammation in the brain that alters neurochemistry, particularly in the prefrontal cortex, which could explain the link between sleep disturbances and attention-deficit/hyperactivity disorder.⁶ Shorter sleep duration in childhood has been shown to contribute to altered neural functioning in brain regions associated with emotional regulation and reward processing, including the prefrontal cortex.^8,9

Previous studies exploring the relationship between childhood sleep concerns and subsequent psychiatric symptoms have typically relied upon parent/caregiver reporting. When standardized screening instruments such as the Sleep Disturbance Scale and Child Behavioral Checklist are utilized, parental reporting has been predictive of subsequent psychiatric symptoms.¹⁰ Although some instruments used in clinical practice such as the Child Behavioral Checklist have not been validated to assess sleep disturbances in children, certain items on standardized screenings such as parental reporting of “trouble sleeping” are valuable in gathering relevant information due to association with sleep latency data obtained from both sleep diaries and actigraphy.¹¹ Instruments reliant on parental reporting obtain data that correlates with data from functional magnetic resonance imaging. For example, parent-reported reduction in total sleep time is associated with weaker internetwork and intranetwork functional connectivity and elevated depressive symptoms scores in adolescents.¹² Subjective sleep observations from caregivers or by self-reporting from the patient and objective measures of sleep abnormalities obtained by formal clinical assessment have both shown to be predictive of major mental health disorders in adolescents and young adults.¹³

Our study aimed to evaluate sleep concerns in early childhood (age 5 years and younger) and the relationship between sleep concerns and future mental health concerns. Using data from a cohort of patients seen in a pediatric sleep medicine practice at an academic medical center in the United States, we investigated caregivers’ subjective reporting of sleep concerns, data obtained from formal polysomnogram (PSG), and development of subsequent psychiatric concerns.

The primary aim of our study was to investigate a relationship between PSG findings in early childhood and development of subsequent psychiatric symptoms. A secondary aim was to explore the level of agreement between caregivers’ subjective reporting of sleep difficulties and clinicians’ findings on PSG.

METHODS

This study was approved by our institutional review board. This was a retrospective study conducted sequentially utilizing data from the Rochester Epidemiology Project, a collaboration of clinics, hospitals, and other medical facilities in Minnesota and Wisconsin for the purpose of research. We identified a cohort of 348 children (ages 5 years 11 months and younger) with sleep difficulties who were referred for a formal pediatric sleep medicine consultation and subsequently underwent a PSG between January 1, 2001, and December 31, 2019. PSG was conducted according to American Academy of Sleep Medicine standards by an American Academy of Sleep Medicine–accredited sleep laboratory. The study cohort (Table 1) was 50.6% biologically male, 72.1% non-Hispanic White, and had a mean age of 33.8 months at the time of PSG. Medical records of study participants were reviewed by the study team to classify the primary sleep complaint articulated by caregiver(s) at the initial sleep medicine consultation and board-certified pediatric sleep medicine clinicians’ interpretation of PSG findings (Table 2). Subsequent development of psychiatric diagnoses and utilization of outpatient psychiatric services were obtained from available medical records in our epidemiologic database using International Classification of Diseases 10th Revision diagnostic codes from recorded encounters reflecting the most common mental health conditions in pediatric patients seen clinically and identified in national data surveillance systems.¹⁴ These included depression (inclusive of major depressive disorder and unspecified depressive disorder), bipolar disorder, persistent depressive disorder, cyclothymia, dysthymia, unspecified mood disorder, attention-deficit/hyperactivity disorder, oppositional defiant disorder, trauma-associated disorders including acute stress disorder and posttraumatic stress disorder, suicide attempts, substance use disorders, and autism spectrum disorder (Table 3).

Table 1.

Demographics of study sample (n = 348).

Age at Polysomnogram	Range: 0–72 months	Mean: 33.8 months
Sex (biologic)
Male, n	176	50.6%
Female, n	172	49.4%
Race (as reported), n
American Indian/Native American	1	0.29%
Asian	4	1.15%
Black/African American	7	2.01%
Other/mixed race	21	6.03%
Unknown/chose not to answer	58	16.7%
White (non-Hispanic)	251	72.1%

Table 2.

Findings from retrospective chart review.

Frequency of Caregiver-Reported Sleep Complaint		Frequency of Clinicians’ Interpretation of Formal PSG
		Normal PSG/no findings	45
Problematic sleep onset	61	Problematic sleep onset	18
“Doesn’t sleep”	16	Behavioral insomnia	3
Frequent nighttime awakenings	112	Frequent nighttime awakenings	24
Snoring	186	Obstructive sleep apnea	171
Restless limb movements	17	Snoring	40
Restless sleep	135	Periodic limb movements of sleep	63
Parasomnia	40	Parasomnia	9
Excessively sleepy (including daytime sleepiness)	29	Disordered breathing of sleep (central sleep apnea or hypoventilation)	62
Other/nonspecific sleep complaint	89	Other findings	48

Totals may exceed size of cohort (n = 348) if multiple parental complaints and/or PSG findings were noted. PSG = polysomnogram.

Table 3.

Prevalence of subsequent psychiatric disorders from retrospective chart review.

Anxiety disorder	168
Mood disorder	120
Psychotic disorder	4
Externalizing disorder	172
Trauma-related disorder	40
Autism spectrum disorder	42
Suicide attempt	22
Substance use disorder	24
Utilization of outpatient psychiatric services	228

Totals may exceed size of cohort (n = 348) if multiple subsequent psychiatric conditions were noted.

The relationship between clinicians’ PSG findings and subsequent psychiatric diagnoses including autism spectrum disorder and substance use, and utilization of outpatient psychiatric services were assessed using chi-squared tests. When expected counts for any cell were less than 5 and therefore too low for the chi-squared test statistic to be appropriate, the Fisher’s exact test was used. Due to the large number of comparisons being made, the results of this study are considered to be exploratory in nature. To account for multiple comparisons, we applied a Bonferroni correction. We had 10 comparisons for each psychiatric diagnosis and the adjusted P-value cutoff was .005.

To evaluate the level of agreement between parent/caregiver concerns and clinician findings from PSG data, statistical analysis with Cohen’s kappa statistic was completed. We used commonly used cutoffs for the interpretation of the level of agreement for the kappa statistic.¹⁵

RESULTS

Autism spectrum disorder (ASD) was the only condition that was present in some patients prior to the completion of the PSG; 4 of 21 patients with ASD (19%) had the diagnosis at the time of PSG. All other psychiatric diagnoses arose after PSG, subsequent to the onset of sleep concerns. Results are noted in Table S4 ^{(640.2KB, pdf)} in the supplemental material and statistical analysis is noted in Table S1 ^{(640.2KB, pdf)} . The only significant finding associating PSG results with psychiatric illness was that patients with ASD were more likely to have obstructive sleep apnea on PSG (P = .0041). All other comparisons were statistically nonsignificant.

Comparing the relationship between caregivers’ subjective reports about sleep and the clinicians’ interpretation of formal PSG (results noted in Table S3 ^{(640.2KB, pdf)} and statistical analysis noted in Table S2 ^{(640.2KB, pdf)} ), kappa values consistently demonstrated slight to fair agreement (kappa value = 0.40 and under). No comparisons were in moderate, substantial, almost perfect, or perfect agreement (kappa value = 0.60–1.00). Results suggest that caregivers’ reported concerns were not predictive of clinicians’ interpretation of formal PSG results.

DISCUSSION

This retrospective review indicates that there are limited relationships between subjective concerns about sleep from caregivers of young children (5 years of age and younger) and objective findings on PSG. Additionally, PSG findings have little predictive value for subsequent development of most psychiatric illness outside of the association between obstructive sleep apnea and autism spectrum disorder, parasomnias and anxiety disorders, and periodic limb movements of sleep and subsequent development of a substance use disorder.

The previous body of literature that exists on the impact of sleep-related concerns and psychiatric illness primarily relies on parents’ subjective reporting of sleep concerns. Our study aimed to determine whether objective PSG data would provide similar insight. Exploratory findings indicate that PSG is a good tool to rule out any underlying sleep difficulties in our study population of children aged 5 years and younger. PSG in children serves as an important and clinically meaningful tool to evaluate several sleep pathologies, including obstructive sleep apnea, periodic limb movement disorder, nocturnal seizures, and parasomnias, and to detect respiratory events.¹⁶ Caregivers’ reports of sleep symptoms using both subjective observations^17,18 and standardized screening instruments^11,12 have been considered a reliable data source for the presence of risks for subsequent mental illness. Screening instruments elicit information on sleep behaviors¹⁹ not detected through PSG, particularly with respect to sleep latency,¹¹ sleep dissatisfaction, and sleep maintenance.²⁰ Caregivers’ reports also provide information on longitudinal sleep patterns that are not as readily detected in the time-limited observations of the sleep laboratory setting. Together with PSG, screeners provide valuable information that could aid in treatment of psychiatric issues in young children. For example, children with ASD often have more sleep issues than the general population.^21,22 Obstructive sleep apnea that they are at risk for can also increase their risk of behavioral difficulties. Our study found a higher likelihood that children with obstructive sleep apnea on PSG would also meet criteria for ASD.

When a history of sleep difficulties in childhood has been present but remits prior to the onset of adolescence, the incidence of psychiatric disorders is similar to that of control patients with no history of sleep disturbances.²³ There are screening instruments that may aid clinicians in identifying pediatric patients in need of treatment of a sleep disorder, such as the Pediatric Sleep Questionnaire or Adolescent Insomnia Questionnaire.²⁰ In addition to development of psychiatric symptoms, children aged 3–5 years with a maternal report of sleep problems have been found to have a higher incidence of early onset of alcohol, cannabis, nicotine, and other illicit substance use by age 12–14 years of age.²⁴ It is prudent for clinicians to monitor young adolescents with a history of childhood sleep disturbances for substance use to allow for earlier intervention.

Appropriate diagnosis and early interventions to manage sleep disorders in children has led to improved neurocognitive functioning and a reduction in behavioral problems.²⁵ Treatment interventions for childhood sleep disorders can include a regulated sleep routine, psychoeducation, regulation of media use, parental limit-setting, optimizing sleep hygiene, and desensitization to permit self-soothing that facilitates sleep.²⁶ These interventions can reduce both internalizing and externalizing symptoms during childhood. Similarly, interventions targeting externalizing behaviors can reduce sleep-related difficulties, though this effect has not been observed with interventions targeting internalizing symptoms alone.²⁷

The present study has limitations that include a small sample size and utilizing PSG data from one night of observation, which may be affected by several confounding factors present in the sleep laboratory. There is also the chance that some of the study participants were still in childhood at the time of data collection and had not yet gone on to develop psychiatric illness or present for treatment of psychiatric symptoms yet or participants sought subsequent psychiatric care outside of member organizations in our registry, leading to an underrepresentation of subsequent psychiatric illness. This was a retrospective chart review study and data collection was based on clinicians’ interpretation of the PSG, which could introduce some degree of variability. Recognizing the presence of these limitations, we hope that our results still serve some clinical utility by highlighting the importance of screening for sleep-related symptoms, gathering data from multiple sources, and not dismissing parents’ or caregivers’ observations when providing care to young children. Future research could include investigating reliable means to obtain objective measures of sleep challenges in young children, in addition to exploring benefits of addressing early childhood sleep disorders and any associated reduction of risk for subsequent mental illness. Factors such as socioeconomic status, psychosocial challenges, comorbid health conditions, duration and severity of sleep-related concerns, age of onset for sleep difficulties, and treating clinicians’ experience with pediatric sleep disorders have the propensity to affect diagnosis and treatment of sleep difficulties in young children. Further investigations into the role these variables may play could provide further guidance for clinicians in implementing early interventions to address sleep disturbances.

CONCLUSIONS

Sleep concerns present in early childhood have been associated with increased risk of psychiatric illness later in life. Caregiver reporting has been the primary source for clinicians regarding the presence of childhood sleep disorders associated with the subsequent development of psychiatric illness. However, sleep pathologies detected on PSG do not appear to demonstrate these same relationships, highlighting the different pathologies detected through PSG compared to those obtained by caregivers’ observations/reporting. Although the use of PSG can help detect specific underlying sleep pathologies in young children, results from these studies, as currently administered, do not appear to offer clinical utility in detecting risk of subsequent psychiatric disease.

DISCLOSURE STATEMENT

All authors have seen and approved the manuscript. This study used the resources of the Rochester Epidemiology Project (REP) medical records-linkage system, which is supported by the National Institute on Aging (AG 058738), by the Mayo Clinic Research Committee, and by fees paid annually by REP users. The content of this article is solely the responsibility of the authors and does not represent the official views of the National Institutes of Health or the Mayo Clinic. Dr. Savitz’s time was supported by the Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery at Mayo Clinic, Rochester, Minnesota. All other authors report no conflicts of interest.

ABBREVIATIONS

ASD

autism spectrum disorder

PSG

polysomnogram