Sleep problems in early childhood may be associated with a higher risk of psychosis and borderline personality disorder (BPD). Persistent nightmares in childhood can also link with sleep problems and increased risk of mental health disorders. The objective of this study is to investigate the associations between parent-reported sleep problems in early childhood and psychotic and BPD symptoms during preadolescence.

This is a cohort study that included a total of 12,488 participants. The participants had sleep problems in childhood, as reported by there parents. The primary outcome was psychotic experiences or BPD symptoms at the age of 11-13 years.

Out of 12,488 participants, 7,155 reported psychotic symptoms, and 6,333 reported BPD symptoms. Higher night awakening frequency at 18 months of age and irregular sleep cycles at 6 months, 30 months, and 5.8 years of age were strongly associated with psychotic experiences in early adolescence. Depression at 10 years of age was a significant mediator in the associations between frequent awakenings and irregular sleep routines with psychosis. 

The study concluded that behavioral sleep problems, like irregular sleep routines and frequent night awakenings, were associated with a significant risk of psychosis and borderline personality disorder at early adolescence.