Predicting Suicide


By Jesica Levingston Mac leod, PhD


The play “suicide is forbidden in spring”. written by Alejandro Casona, describes an organization that helps potential suicide patients to end their lives, but the truth is that the doctors really want to avoid the sad end, and… they actually save the patients. They work with the “leitmotiv” that if you really want to finish your life, you will just do it, but the search for help is an indicator or alert signal of some survival and seek for attention behavior.

As reported by the Health Research found worldwide, 1 million suicides are committed by year. This means 1 death every 40 seconds. According to the CDC, In United States the percentage of suicidal is around 0.012%, where is the 10th leading cause of death. North America has 1 suicide every 13 minutes.The suicidal capital of the world is Greenland with a 108.1 suicide rate, followed by South Korea with 31.7. China is in the seventh place, it accounts for almost one third of all the suicides, and differently than the other countries it is the only one where women have a higher suicidal rate than men. Indeed, 3 years ago the terrible news about how in some factories, like Foxconn, making sought-after Apple iPads and iPhones were forcing staff to sign pledges not to commit suicide. Among 2013 at least 14 workers at Foxconn factories have taken the decision of terminating the horrendous working and housing conditions, ending their lives.


This initiative to attempt against your own life was been related to mental illness (almost in 50% of the cases) and metabolic disorders. The most implemented way of killing themselves is firearms, followed by suffocation/hanging and falls. The alarming fact is that rates of suicide have increased by 60% in the last 30 years, especially in developed countries. Also, you must consider that for every suicide that results in death there are between 10 to 40 attempted suicides. But what does bring a human been to the edge… and push him to jump?

New research has found that the answer would be the lack of the correct expression of one gene. Yes, only the downregulation of SKA2, the guilty gene, could be a biomarker for detecting suicidal behaviors. SKA2 stands for spindle and kinetochore associated complex subunit 2. The protein encoded by this gene is part of a microtubule biding complex that is essential for proper chromosomal segregation.

When they examined the postmortem brain samples from 3 independent cohorts (around 29 from suicide assesd humans and 29 controls per each group) they found that SKA2 had lower expression levels in the suicide cases than in the control, and its expression was negatively associated with DNA methylation. The chemical addition of a methyl group can activate or negatively modulate a gene, as it is considered an epigenetic modification.

I guess you are thinking: these are “Frankenstein” samples, how can this gene be related to really live human beings? Well, apparently the Johns Hopkins researchers also made the same question. In order to answer it they collected blood samples from other 3 independent cohorts with suicidal ideation and controls (with a number of subjects of 22, 51 and 327 each). In these study, the expression of the SKA2 gene was significantly reduced in suicide decedents. Furthermore, they analyzed levels of salivary cortisol. Cortisol is implicated in the glucocorticoid receptor transactivation and stress response. The results suggested that SKA2 epigenetic and genetic variation may modulate cortisol expression. The most important discovery was that the model that they generated based on these data allowed them to predict the suicidal ideation of subjects just using blood samples. They analyzed the methylated status of the SKA2 gene, which correlated with the suicidal attempts.

The great thinker Albert Camus ones recalled the attention in this issue when he said: There is but one truly serious philosophical problem and that is suicide.”  For some in risk groups, like the soldiers who are coming back home with traumas after the war, the possibility of attempts against their lives is a ghost that has taken a lot of lives. This simple blood test can point out which individuals could be in risk and therefore they may get a correct follow up and treatment that might end preventing the catastrophe. Some high pressure jobs can also implement this analysis to avoid the lost of lives, giving correct care to people who tested positive. And even closer to all: would you like to know if you have this tendency printed on your DNA? Or your partner? Or your kids?

While you think about this, let me leave you with a relief quote: “If I had no sense of humor, I would long ago have committed suicide.” Perhaps, you would be surprise to know that the wise man who said this was the Dr. Mahatma Gandhi, whom almost killed himself in a starving protest trying to obtain the independence of the Indian Republic.