Health Highlights: Jan. 4, 2019

Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

Social Media Tied to Depression in Teens, Especially Girls

Using social media for five hours or more per day is tied to a big jump in risk for depression among 14-year-olds, and especially for girls, a new British study shows.

As compared to girls who spent just one to three hours daily on social media, girls who spent five or more hours on Snapchat, Instagram and the like had 50 percent higher odds for depressive symptoms, says a team from University College London.

The number was somewhat less for boys -- a 35 percent hike in risk for boys who used social media five-plus hours per day.

"We were quite surprised when we saw the figures and we saw those raw percentages: the fact that the magnitude of association was so much larger for girls than for boys," study author Yvonne Kelly, a professor of epidemiology and public health at the university, told CNN.

The researchers stressed that the study couldn't prove that excessive social media use caused depressive symptoms, only that there was an association. Depressive symptoms included feelings of loneliness, unhappiness or restlessness.

The researchers looked at data from a national study that included nearly 11,000 British 14-year-olds born between 2000 and 2002.

The data showed that girls were typically on social media more than boys: about 43 percent of girls used social media three or more hours per day, compared to about 22 percent of boys.

"For both girls and boys, the more social media they use, the more likely they are to have mental health problems, but not that many studies have been able to look for the explanations why," Kelly told CNN.

"We looked at four potential explanations simultaneously, and this is the first paper to do that. We looked at sleeping habits; experiences online, so cyberbullying; how they thought about their bodies, or their body image, and whether they were happy with how they looked; and their self-esteem," she explained.

"All of those four things -- the sleep, the cyberharassment, the body image or happiness with appearance, and the self-esteem -- they are all linked with the risk of having depression," Kelly said.

She noted that girls tend to gravitate towards Instagram and Snapchat. Those platforms are "more based around physical appearance, taking photographs and commenting on those photographs," she said, so the stronger link between social media and depression in girls may have "to do with the nature of use."

The findings were published Jan. 3 in EClinicalMedicine.