People who post on social media overnight are more likely to have poor mental wellbeing, a study suggests.
Overnight users are also more likely to report symptoms of depression and anxiety, researchers found.
Experts said that most studies on mental wellbeing and social media have concentrated on frequency of social media use. They wanted to assess whether timing plays a role.
As a result, they took to platform X, formerly known as Twitter, to assess overnight usage, as measured by the time that people posted.
This was correlated with data from a long-term study tracking the health of people from the west of the U.K. - the Children of the 90s study, also known as the Avon Longitudinal Study of Children and Parents.
Some 310 people were chosen to be involved in the study based on the timing of their tweets and when they answered questionnaires about their wellbeing.
Overall researchers examined 18,288 tweets, including retweets, posted between January 2008 and February 2023 - before the site changed its name to X.
The study found that people who, on average, tweeted through the night from 11 p.m. to 5 a.m. appeared to have "meaningfully worse mental wellbeing than those who tweeted during the daytime."
The authors, led by academics at the University of Bristol, said that tweeting overnight explained almost 2% of variation in mental wellbeing. They also found a link between overnight tweeting with depression and anxiety, but these were not as strong.
The team highlighted how nighttime use of social media "could displace sleep" as people stay awake to use it.
They added that posting and messaging at night could lead to "cognitive arousal," and said that blue light from smartphones could "inhibit the production of the hormone melatonin."
"All these factors may combine to delay sleep onset, and lead to worse sleep quality and quantity, they wrote in the journal Scientific Reports."
"Improved sleep-related outcomes are in turn associated with better mental health."
Daniel Joinson, doctoral researcher at the University of Bristol and lead author of the paper, said: "While social media is often treated like a monolith, its impact on mental health will depend on the exact behaviors the user performs and the experiences they have on these platforms."
"Our paper highlights the potential harm of a very specific behavior: nighttime content posting."
"Research like ours could help inform interventions or legislation that aim to deter harmful social media use, whilst enabling beneficial behaviors or experiences."
