Sleep during childhood is crucial and has been associated with the development of mental health problems in later stages of life (Morales-Muñoz & Gregory, 2023). In a recent study from our team, we found that children who experience chronic lack of sleep from infancy may be at increased risk of developing psychosis in early adulthood (Morales-Muñoz et al., 2024).
To do this study, we examined information on nighttime sleep duration from a large cohort study of children from the UK aged between six months and seven years old, and also information on psychosis at the age of 24 years old from the same participants. We found that children who persistently slept fewer hours, throughout this time period, were more than twice as likely to develop a psychotic disorder in early adulthood, and nearly four times as likely to have a psychotic episode. While previous research has highlighted links between sleep problems and psychosis at specific time points (Fisher et al., 2014; Thompson et al., 2015; Morales-Muñoz et al., 2020), this is the first study to show that persistent lack of sleep in childhood is a strong predictor of psychosis.
Further, we looked at the overall immune system health in the children to see whether impairments in the immune system could also account for some of the associations between lack of sleep and psychosis. This was tested at nine years old by measuring levels of inflammation in blood samples. Our results showed that a weakened immune system could partially explain the links between lack of sleep and psychosis. However, it is important to acknowledge that there are other unknown factors that are also likely to be important, but which we did not explore in this study.
Therefore, our study provides reliable evidence that chronic lack of sleep in childhood could put the child at risk of developing psychosis in adulthood, and that impairments in the immune system could also be playing a role in these associations.
There are three key messages to take from this study. First, it is entirely normal for children to suffer from sleep problems at different points in their childhood, but it is also important to know when it might be time to seek help. Sometimes sleep can become a persistent and chronic problem, and this is where we see links with psychiatric illness in adulthood. Therefore, this is when parents or others close to the child (e.g., teachers, social workers, paediatricians) should seek professional help to address those sleep problems. Second, the good news is that we know that it is possible to improve our sleep patterns and behaviours. While persistent lack of sleep may not be the only cause of psychosis in early adulthood, our research suggests that it is a contributing factor, and it is something that can be addressed. For instance, there are a number of behavioural interventions targeted at sleep that can be implemented during childhood and which have proven to be effective to improve sleep problems in childhood (Aslund et al., 2018). Third, we know that early intervention is really important in helping young people with mental illness. Understanding the role that good sleep hygiene plays in positive mental health could be a really important part of this process.
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