Twice as many girls in secondary school said they had problems relating to social media use compared with boys, a survey has found.
One in five girls aged between 13 and 15 reported problems, such as struggling to limit time on social media or it causing conflict with families and friends, compared with one in 10 boys of the same age.
The results are part of one of the largest surveys of school children in Wales.
Public Health Wales (PHW), which conducted the study with Cardiff University, said the reason behind the different rates was not clear cut.