Depression is a complex mental disorder that, although it can affect all kinds of people, a multitude of environmental, sociocultural and also genetic factors come into play at its origin. Regarding the latter, numerous studies have found a greater probability of suffering anxiety attacks and depression among those who have a first-degree relative who has suffered the same disease. Experts have not classified depression as a hereditary disease, although the predisposition to its development can be transmitted through genes.
Genes inherited from parents not only affect physical traits such as constitution or face, but also issues such as blood pressure values or the way neurotransmitters in the brain are regulated. The secretion of hormones such as cortisol, which raises blood glucose levels and increases heart rate, is genetically determined. In other words, a patient with a brain that produces high levels of cortisol is likely to have inherited this quality from her parents and, therefore, have greater difficulty dealing with episodes of stress or anxiety.
German and American researchers have conducted twin and family studies to try to prove the existence of a genetic component to depression.
The German doctor Klaus-Peter Lech led a sample with half a thousand people in which they clarified the existence of two variants of a gene that determines the formation of molecules that transport and regulate serotonin, a hormone that is involved in anxiety.
Their conclusion was that individuals who had a short variant of the gene for the serotonin transporter molecule had higher levels of anxiety than those who had a molecule with a long amino acid frequency. The short variant produces fewer molecules, preventing neurons from absorbing serotonin and making the subject more sensitive to emotional stimuli.
The National Institute of Mental Health in the United States also discovered that the gene responsible for transporting serotonin modulates the functioning of the amygdala in the brain responsible for reacting to fear. Each person inherits from each parent a copy of the SLC6A4 gene, of which, if they receive at least one of the short variant, they will present greater activity in the region of the brain that responds to stimuli such as fear and, therefore, will be more vulnerable to fear. stressful situations.
Some patients inherit a genetic predisposition to depression, but that doesn't mean everyone develops it. Other types of factors intervene in the disease that can affect subjects without any genetic predisposition. Although they are not hereditary, suffering from abuse or mistreatment during childhood or experiencing trauma are events that people drag along throughout their lives and can increase the risk of suffering from depression, according to psychologist Blanca Fernández Tobar, as well such as isolation and lack of social support.
