Associations between Sleep Problems, Psychotic Experiences and Mental Disorders in Children at Familial High Risk of Schizophrenia or Bipolar Disorder and Population-based controls - The Danish High Risk and Resilience Study.
Søndergaard A, Hemager N, et al. • Schizophrenia research • 2026
Nightmares, prolonged sleep latency, and nocturnal awakenings are associated with psychotic experiences and mental disorders in children at familial high risk of schizophrenia or bipolar disorder and population-based controls, with associations being non-differential across familial risk groups.
Key Findings
Results
Children with psychotic experiences had significantly higher odds of all three sleep problems, but only the association with nocturnal awakenings remained significant after adjustment for mental disorders.
Psychotic experiences were associated with nightmares, prolonged sleep latency, and nocturnal awakenings in unadjusted analyses
After adjustment for mental disorders, only the association between psychotic experiences and nocturnal awakenings remained statistically significant
This suggests mental disorder status may mediate or confound the relationship between psychotic experiences and some sleep problems
Psychotic experiences were assessed using the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS) present and lifetime version
Results
Children with a mental disorder had significantly higher odds of nightmares, prolonged sleep latency, and nocturnal awakenings.
All three sleep problems — nightmares, prolonged sleep latency, and nocturnal awakenings — were significantly associated with having a mental disorder
Mental disorders were assessed using the semi-structured K-SADS interview
The associations between mental disorder and all three sleep problems remained significant in the analyses
Primary caregivers of the children provided information about sleep problems
Results
The associations between sleep problems and psychotic experiences and mental disorders were non-differential across familial risk groups.
The study included three groups: 170 children at familial high risk of schizophrenia (FHR-SZ), 103 at familial high risk of bipolar disorder (FHR-BP), and 174 population-based controls
All children were 11–12 years old
No statistically significant differences in the strength of associations between sleep problems and psychotic experiences or mental disorders were found across the three risk groups
This suggests the relationship between sleep problems and psychotic/mental health outcomes is not specific to familial high-risk status
Methods
The study used caregiver-reported sleep measures and a semi-structured clinical interview to assess psychotic experiences and mental disorders in 447 children.
Total sample size was 447 eleven-to-twelve-year-old children
Sleep problems assessed included nightmares, prolonged sleep latency, and nocturnal awakenings, reported by primary caregivers
Psychotic experiences and mental disorders were assessed with the K-SADS present and lifetime version
The sample was drawn from the Danish High Risk and Resilience Study
Background
Sleep problems are linked to schizophrenia and bipolar disorder and often precede the onset of manifest illness, motivating their study as early risk markers.
The authors note that sleep problems often precede the onset of schizophrenia and bipolar disorder
Psychotic experiences and mental disorders during childhood are identified as risk factors for later development of schizophrenia and bipolar disorder
The study was motivated by the potential for sleep problems to serve as an 'unrecognized marker of risk for mental health problems'
The authors recommend that sleep problems should be assessed in child and adolescent mental health services through anamnestic interviews or questionnaires
What This Means
This research suggests that sleep problems — specifically nightmares, taking a long time to fall asleep, and waking up during the night — are linked to both psychotic experiences (such as hallucinations or unusual beliefs) and diagnosable mental disorders in children around 11–12 years of age. The study followed nearly 450 children, including those whose parents had schizophrenia or bipolar disorder (putting the children at higher genetic risk), as well as children from the general population. Importantly, these associations were similar across all three groups, meaning the link between sleep problems and mental health difficulties was not unique to children with a family history of serious mental illness.
One notable finding is that when mental disorder was taken into account statistically, most of the connection between psychotic experiences and sleep problems disappeared — except for nighttime awakenings, which remained independently associated with psychotic experiences. This suggests that much of the overlap between sleep problems and psychotic experiences may be explained by the presence of a broader mental health condition.
This research suggests that asking about sleep could be a simple and useful way for clinicians working with children and adolescents to identify those who may be struggling with their mental health. Since sleep problems can appear before more serious mental health conditions fully develop, recognizing them early — through routine questions to parents or caregivers — could help flag children who might benefit from closer monitoring or support.
Søndergaard A, Hemager N, Wilms M, Rohd S, Krantz M, Greve A, et al.. (2026). Associations between Sleep Problems, Psychotic Experiences and Mental Disorders in Children at Familial High Risk of Schizophrenia or Bipolar Disorder and Population-based controls - The Danish High Risk and Resilience Study.. Schizophrenia research. https://doi.org/10.1016/j.schres.2026.02.020