It claims, among other things. that Females tend to suffer from depression at a rate two to three times
higher than their male counterparts, and these gender differences are
known to begin during adolescence .
Adolescent depression has been linked to violence , smoking [5,6] substance use , eating behaviors  and increased suicide risk [9,10]. It also has been linked to sexual activities ...
...romantically involved adolescents, especially females, were more likely to be depressed than those who were not .
Hallfors et al. also found that adolescents who engaged in any sexual
activities were at increased odds for reporting depression, suicidal thoughts and suicide attempts . Again, the odds were higher for females than males.
The study discovered that depression rates in girls increase with the number of sexual partners they have:
The main finding of this study is that a relationship exists between
mental health and number of sexual partners. As the number of lifetime
sexual partners increases, the prevalence of sadness, suicide ideation,
making a suicide plan, and attempting suicide also increases.
It's almost like pair-bonding were a real thing or something...