Why is this worrying? Some kids have mental health problems. This doesn't show that more kids have mental health problems now.
>>> Young people who spend seven hours or more a day on screens are more than twice as likely to be diagnosed with depression or anxiety than those who use screens for an hour a day, finds a new study published in the journal Preventive Medicine Reports.
Are you suggesting 1 hour is harmless and 7 hours is extremely rare (assuming that is already proven) and hence nothing is new in this article?
If the same number of kids have mental health issues as before there were so many screens, there is nothing to worry about. I'll start to worry if more kids have mental health problems, and then it makes sense to figure out what is causing that increase.