There are no conclusive statistics about the incidence of depression after bypass surgery.
The current incidence of depression is thought to be around three women for every man.
Some showed a high incidence of depression or a likelihood of having been abused as children; some did not.
"We know LGBT people, especially young LGBT people, have higher incidence of depression, self-harming and suicide," says Butchart-Kelly.
The incidence of depression climbs in both sexes during puberty, but the climb is steepest for girls.
Psychologists say alcohol has increased the incidence of depression, and public fights are common after city pubs shut for the night.
It is unlikely that any single gene, hormone level or type of experience explains the higher incidence of depression in women, experts say.
She believes that the baby boom generation has a higher incidence of depression than previous ones.
It did, however, substantially reduce the incidence of depression, and it made them vastly more financially secure.
"There is substantial evidence that repeated trauma does occur on the football field and those who have sustained this kind of trauma have a higher incidence of depression than those who have not," Cantu said.
The results found that the incidence of depression symptoms was 17.6 %.
