Interesting read. Probably lots of different things. One of the negative effects of the internet and social media is that it has increased the degree to which people are comparing themselves to each other on superficial metrics.
This is probably most harmful to females who are frequently judged on the most superficial of all metrics, their sexual appeal. For girls going through puberty and trying to find where they fit socially, it's a constant bombardment of images of girls who are better looking than them, getting more "likes" than them, seemingly living better lives than them. It's inevitable that some of those girls will be more negatively impacted than others.
What's interesting to me is that some of the male spikes seem to occur around times of military or economic turmoil. I'd be curious why lies behind that.