Girls who start using social media younger tend to be unhappier as they progress through their teens, new research has shown.
Social media seems to have a greater impact on the well-being of girls, scientists at the University of Essex and University College London found.
Girls who spent an hour or more on social media by the age of 10 showed lower well-being by the time they reached 15.
The research, based on a survey of 9,859 UK adolescents aged 10 to 15 years old, found adolescent girls used social media more than boys.
By age 13, about half of the girls surveyed used social media for more than one hour per day on a typical school day, compared to one-third of boys.
Social media use increased with age in both genders, but girls were still more prolific users than boys by the age of 15, with 59% of girls interacting on social media for an hour or more each day compared to 46% of boys.
The study, published in the BMC Public Health journal, found that well-being declined throughout adolescence for boys and girls, but the drop was larger for girls.
Researchers found that throughout adolescence happiness scores dropped nearly three points from 36.9 to 33.3 in girls, and two points from 36.02 to 34.55 in boys.
Participants were assessed using a happiness score on different aspects of their lives including family and school.
They also filled out a "strengths and difficulties" questionnaire measuring negative aspects of well-being such as emotional and behavioural problems.
The study used data from the youth panel of the UK Household Panel Study between 2009 and 2015 - a large national survey which interviews all members of a household annually.
Dr Cara Brooker, one of the study's authors, said: "Our findings suggest that it is important to monitor early interactions with social media, particularly in girls, as this could have an impact on well-being later in adolescence and perhaps throughout adulthood.
"Since we did not observe an association between social media use and well-being among boys, other factors, such as the amount of time spent gaming, might be associated with the boys' observed decline in well-being."
The researchers warned that the link between social media and well-being may have been underestimated in the figures because the study used self-reported data and only social media interactions on school days were recorded.