Short answers, pulled from the story.
Suicide is the act of intentionally causing one's own death and resulted in 828,000 deaths globally in 2015. This figure rose from 712,000 in 1990 even as the age-standardized death rate decreased by 23.3 percent. Suicide ranks as the tenth leading cause of death worldwide accounting for approximately 1.5 percent of all deaths.
Post-mortem studies have found reduced levels of brain-derived neurotrophic factor in the hippocampus and prefront cortex of those who die by suicide. Research indicates that mental disorders are present at the time of suicide between 27 percent and more than 90 percent of the time with major depressive disorder accounting for half of all cases. Serotonin is believed to be low in those who die by suicide and low levels of brain-derived neurotrophic factor are directly associated with suicide.
The Christian Church condemned suicide as the work of the Devil at the Council of Arles in 452. By the 17th century the criminal ordinance issued by Louis XIV of France in 1670 was so severe that the dead person's body was drawn through the streets face down and hung on a garbage heap. In ancient Athens a person who died by suicide without state approval was denied a normal burial and sometimes had their hand cut off and buried separately.
Globally death by suicide occurs about 1.8 times more often in males than females but in the Western world males die three to four times more often by means of suicide than do females. In China the pattern is reversed with one of the highest female suicide rates in the world and the only country where it is higher than that of men. Males tend to use more lethal means such as firearms which have an 80 to 90 percent death rate whereas females are more likely to attempt suicide through drug overdoses.
The Werther effect is a phenomenon where detailed descriptions of suicide methods can be imitated in vulnerable people named after the protagonist in Goethe's The Sorrows of Young Werther who killed himself and was emulated by many admirers of the book. The media plays a critical role in shaping these outcomes as the United States accounted for 44 percent of global gun suicides in 2019. Guidelines for reporting suicide have been developed to reduce the risk of imitation yet getting buy-in from the media industry remains a challenge.
The World Suicide Prevention Day is observed annually on the 10th of September supported by the International Association for Suicide Prevention and the World Health Organization. Lithium has been proven to reduce the risk of suicide in mood disorders by 87 percent in randomized controlled trials. Crisis hotlines such as 988 in North America and 13 11 14 in Australia are common resources though their effectiveness has not been well studied.