If you have suffered from depression, then you probably have heard all sorts of comments coming from others, and sometimes even doctors, about its origins. For them, and sometimes for us, it is often all in our head, because of a very specific event, or just a general situation that we do not feel at ease with. Even though these factors, along with many others, play an important role in the triggering of a depression, studies are starting to show that our genes could be playing their part as well.
Recent studies have shown that, among people whose parents experienced severe depression, the incidence of people experiencing symptoms of severe depression themselves goes up to 9%, against a 3% incidence observed among the general population. The probability is even higher if the parent went through a depressive episode before the age of 16. Similarly, monozygotic twins (twins sharing 100% of their DNA) were 40% to both experience depression, against only 10% for dizigotic twins (twins sharing 50% of their DNA).
Genomics have found out that although several genes are involved in the creation of a breeding ground for depression, the main culprit may be found in the gene 5-HTTLPR. This gene is involved in transportation of serotonin in the brain. However, over the years, research has taken a step forward just to take two steps back many times, as it identified several genes involved with depression in a first study, but then found itself incapable of reaching the same findings again with a different panel of people. Evenmore disappointing, when a team of 80 international scientists examined more than 2.4 million DNA variations provided by 34,549 people, they were not able to identify a single one that could be associated with depression.
Still, scientists remain optimistic that the answer will come out in the near future, and that the exact role of the DNA in depression will be clearly identified. Some of them believe that to achieve so, they would need to look at much bigger samples of the population, which is obviously a challenge. This would potentially greatly help people suffering from this affection, as it would open the door to the development of new forms of medical treatment.