What is the role of childhood sleep problems in the development of future mental health problems in adolescence?
Existing previous research indicates that sleep is a key factor associated with developmental psychopathologic symptoms. However, the nature of this association is still unclear. For example, we still do not know whether sleep problems may precede the development of certain mental health problems, or whether they merely co-occur together. In this blog post, Dr Isabel Morales-Muñoz talks about her latest research into sleep and it’s power.
Why did we do the research?
Few recent longitudinal attempts have shown that nightmares in childhood associated with borderline personality disorder (BPD) and psychotic symptoms in adolescence. However, it was still unknown whether other more frequent sleep problems that commonly appear in childhood (i.e. behavioural sleep problems, such as frequent night awakenings, short sleep duration, late bedtime or irregular sleep routines) precede the onset of BPD and psychotic symptoms in adolescence. Furthermore, there is no clear understanding of the potential mechanisms explaining this association between sleep problems and mental health problems, such as BPD and psychotic symptoms. Among these potential mechanisms, depression could be considered a good candidate, as it plays an important role in the development of both sleep and mental health problems.
Therefore, in this study we first investigated whether some specific behavioural sleep problems in childhood (from 6 months to 6 years old) associated with the development of prospective BPD and psychotic symptoms in adolescence. Secondly, we were interested in examining whether depression at the age of 10 years mediated this association between behavioral sleep problems in early childhood and BPD and psychotic symptoms in adolescence.
How did we do the research?
To address these two main objectives, we used a large longitudinal population-based cohort in the UK (i.e. ALSPAC cohort); more specifically, the sample of this study comprised more than 7000 children, and we obtained parent-reported sleep information on frequency of night awakenings, sleep duration, bedtime and sleep routines, and also self-reported information on BPD and psychotic symptomatology in adolescence (between 11 and 13 years old), and self-reported depressive symptomatology in late childhood (10 years old), in addition to other relevant socio-demographic and developmental information.
What did the research find?
The most significant finding of this study was that the associations between behavioural sleep problems in childhood and BPD symptoms in adolescence, and the associations between behavioural sleep problems in childhood and psychotic symptoms in adolescence, followed different pathways. For instance, frequent night awakenings at 18 months and irregular sleep routines during childhood were associated with psychotic symptoms in adolescence, while short sleep duration at the age of 3.5 years related to BPD symptoms. Also, another relevant finding was that depression at 10 years only mediated the association between behavioral sleep problems and psychosis, while the mediating role of depression did not happen for BPD symptoms.
They key message of our study is that some specific sleep problems that occur at very early stages of childhood might explain the development of some specific mental health problems in adolescence. Further, specific sleep problems, at certain stages of the child´s development, associate with specific mental health problems in adolescence, and in a different manner. For instance, frequent night awakenings and irregular sleep routines are more relevant in psychosis; while the target in BPD should be sleep duration. Also, depression at the age of 10 months plays a very important role, as it partially explains the associations between these specific sleep problems and psychotic symptoms, while it seems that there could be a direct association between sleep problems and borderline personality disorder.
However, like in other studies, ours had some limitations, too. One of the limitations is that sleep problems were parent-reported, so in that sense we cannot forget that these are subjective measures that could be influenced by some parental factors, such as parental mental health, family environment or parenting styles. Other limitation is that there are some other factors that might affect the associations reported here, like developmental problems in the children (e.g. developmental delay, hyperactivity), prenatal medication taken by the mother, prenatal and postnatal paternal factors or environmental factors. Finally, other mediating factors that might explain these associations could be the (i) potential role of emotional dysregulation, especially in the association between sleep and BPD symptoms; and also the (ii) potential role of certain cognitive impairments (e.g. deficits in the frontal lobe, which regulates the executive functions, such as inhibition, working memory, decision making...) in the associations between sleep and psychotic experiences. For the purpose of this study, we only focused on the potential role of depression as one potential explanation of these associations, but further studies should investigate the role of other relevant mediating factors.
These findings highlight the relevance of assessing and/or considering the important role of sleep problems already in early childhood as a potential risk factor for the development of prospective psychopathology in adolescence. Furthermore, different behavioural sleep problems should be addressed depending on the psychopathology (i.e. frequent night awakenings and irregular sleep routines are more relevant in psychosis; while the target in BPD should be sleep duration).
So how does this research help us understand what is going on and support children and families?
The results of this study could have important implications for helping practitioners identify children who might be at higher risk for psychotic experiences or BPD symptoms in adolescence, and potentially lead to the design of more effectively targeted sleep or psychological interventions to prevent the onset or attenuate these mental disorders. Furthermore, the message that could be sent to parents is that if they are worried about their child having some sleep problems, they should consult a specialist. In many cases, these parental worries are indeed part of a normative developmental stage (such as for example their child waking up few times during the night, or having problems to fall asleep), but still it would be beneficial for them to be aware of these normative patterns; but in other cases, these are indeed part of a developmental problem. Sleep problems in children can be effectively treated with behavioural techniques and with parental education on sleep hygiene, among others; therefore, this is a positive message for those parents who might be worried about their children´s sleep. This way, sleep can be effectively improved in early childhood and this could indeed prevent or ameliorate the development of future mental health problems.
Dr Isabel Morales-Muñoz is an Honorary Research Fellow at the Institute for Mental Health (IMH). Dr Morales-Muñoz holds the position of Academy of Finland postdoctoral research fellow, at the National Institute for Health and Welfare (THL), in Helsinki, Finland. Her main research interests lie within the field of sleep, neuropsychology and mental health.
Check out the paper here:
Other media about this research can be found here:
https://edition.cnn.com/2020/07/01/health/infant-baby-sleep-mental-health-wellness/index.html