New study finds link between sleep problems and self-harm in teenage years

Young teenagers who have sleep problems are at higher risk of engaging in self-harm by the time they turn 17, a new study has found.

UK researchers found that self-reported sleep problems at age 14 were directly associated with self-harming behaviour both then and at age 17.

The results indicate that sleep patterns can have long-lasting impacts on teenagers’ wellbeing, the researchers said.

“Self-harm is one of the leading causes of death among adolescents and young adults,” said Nicole Tang, one of the study’s authors and a clinical and health psychologist at the University of Warwick.

“Knowing that poor and fragmented sleep is often a marker preceding or co-occurring with suicidal thoughts and behaviour, it gives us a useful focus for risk monitoring and early prevention," she added.

In recent years, sleep deficiency and self-harm in young people have separately emerged as public health concerns in Europe.

The share of teenagers who meet sleep recommendations on school days range from 32 per cent in Poland to 86.3 per cent in the Flemish part of Belgium, a 2020 review found.

The American Academy of Sleep Medicine (AASM) recommends that 13- to 18-year-olds get eight to ten hours of sleep per night during the week.

The latest study, which was published in the Journal of Child Psychology and Psychiatry, included more than 10,000 participants aged 14 in the United Kingdom. 

They were asked about their sleep problems, including how long they slept on school days, how long it took them to get to sleep, and how often they woke up during the night. 

The 14-year-olds were also asked whether they had deliberately hurt or injured themselves. 

They were asked the same question  again three years later when they were surveyed at age 17.

When young teens got less sleep on school nights, woke up more often overnight, or took longer to fall asleep, they were more likely to report self-harm at ages 14 and 17, the study found.

Sleep problems raised these risks even after the researchers accounted for other known factors, such as age, sex, socioeconomic status, previous instances of self-harm, self-esteem, and depression.

It’s still not clear exactly why there appears to be a link between poor sleep and self-harm. The researchers tested whether poor sleep could be linked to worse decision-making, thus raising the risk of self-harm, but this turned out not to be the case.

Even so, researchers noted that sleep is a “modifiable risk factor,” meaning improving teenagers’ sleep quality and length may help reduce the risk of self-harm and have long-lasting benefits.

“While this is clearly an unfavourable relationship … we can actually do something about it,” said Michaela Pawley, one of the study’s authors and a psychology researcher at the University of Warwick.

“If the link between sleep and self-harm holds true and with well-placed interventions in schools and homes, there is a lot we can do to turn the tide,” she added.

If you are contemplating suicide and need to talk, please reach out to Befrienders Worldwide, an international organisation with helplines in 32 countries. Visit befrienders.org to find the telephone number for your location.