Flashmag Digizine Edition Issue 110 October 2020 - Page 103

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Flashmag October 2020 www.flashmag.net

As the low-functioning BDNF met variation is a risk factor for suicidal behaviour, it may also be possible to develop a compound to increase BDNF functioning, Dr. Kennedy says.

About 90 per cent of people who have died by suicide have at least one mental health disorder, the researchers note. Within the studies they reviewed, participants had schizophrenia, depression, bipolar disorder or general mood disorders. In each case, the researchers compared the genotypes of people who had attempted or completed suicide with those who were non-suicidal.

"Our findings provide a small piece of the puzzle on what causes suicidal behaviour," says Dr. Kennedy.

"When assessing a person's suicide risk, it's also important to consider environmental risk factors, such as early childhood or recent trauma, the use of addictive drugs or medications and other factors."

Suicide is common worldwide. Nearly 800,000 people successfully commit suicide every year. In the past, suicide was assumed to be due to some form of mental illness or in reaction to a particular life event. However, people who have no obvious risk factors still commit suicide in significant numbers making it imperative that we consider the role of another important factor: our genes. Family studies have clearly demonstrated the substantial heritability of suicidal behavior.

The question then is what exactly is being inherited? Can genes for depression or other mental illnesses account for the worldwide occurrence? Thus far, finding the culpable gene(s) has not been easy due to the necessity of collecting data from very large numbers of people who have no risk factors.

Two recently published studies collected data from almost five hundred thousand people with, and without, known mental disorders. Their purpose was to determine whether there was a common genetic variation that might underlie committing suicide. They calculated the genetic correlation between specific gene variations with hundreds of other traits, including those that predispose people to mental disorders, in order to estimate the genetic contribution to suicide.

The studies confirmed some well-known associations, such as significant genetic correlations between suicide and depressive symptoms, neuroticism, major depressive disorder and schizophrenia. These results emphasize the heritable component of suicide. The studies also identified two significant genetic correlations with non-psychiatric traits.