Lately there is a disease that is gaining ground and does not seem willing to give us respite: depression. The World Health Organization (WHO) estimates that at least 322 million people in the world suffer from it18% more than a decade ago.
Also known as major depressive disorder, it is characterized by low mood, decreased interest, impaired cognitive function, and problems with sleep or appetite. It is also recurrent and costly, with a tendency to become chronic, and generates suffering and disability.
Do we know what causes it? Unfortunately not. However, there are enough studies on its risk factors, that is, the characteristics and circumstances that increase the probability that we fall into its clutches.
Some, as common sense dictates, are related to dramatic life events, such as the death of a loved one or the diagnosis of a serious illness. However, there are many other risk factors for depression that are not as well known, although they are still important.
We refer to factors sociodemographicfactors genetic and neurological, personal factors, adverse experiences and comorbidity.
Sociodemographic factors: twice as many depressed women
Perhaps the most consistent and well-known risk factor for depression within sociodemographic factors is sex. Universally, regardless of country or culture, women are twice as likely to experience depression as men after puberty.
However, other risk factors for depression have also been found, such as age, marital status, educational level or race. Specifically, this disorder more often in young adults; in single, separated or divorced people; and in those with a lower educational level and of white race.
It has also been found that depression is more common in low-income, unemployed and residents in urban areas.
Genetic factors: the tendency to depression is inherited
First-degree relatives of patients with depression show increased risk about three times as likely to develop this disorder. Studies suggest that between 26% and 42% of the variation in depression is due to genetic influences. There are also indications that this heritability is more evident in depressions of early onset and relapsing course.
Still, no specific gene or set of genes has been found to be reliably associated with depression or involved in parental transmission… It’s too heterogeneous.
Neurological factors: the amygdala becomes hyperactive
In parallel, neuronal abnormalities have been documented in adults in certain regions of the brain. Structural abnormalities have been found primarily in the gray matter volumes of the hippocampus, the amygdalathe anterior cingulate cortex, and the dorsolateral prefrontal cortex.
Depressing us also changes neuronal function. Specifically, there is increased brain activation in subcortical emotion-processing regions, such as the amygdala and limbic circuits, combined with attenuated activation in cognitive control regions.
It doesn’t just happen in adults. The same abnormalities in neuronal function and structure have been identified in children of parents with depression, even before the onset of the depressive episode. And that makes us suspect that they make us more vulnerable to this disorder.
Personal factors: introversion and excessive self-criticism
There is evidence that the tendency to experience negative emotions (fear, anger, sadness, anxiety), as well as mood swings and negative thoughts, implies a increased risk of developing depression. It is what is known as neuroticism.
On the other hand, there are more cases of depression among people than score high on introversion. It refers to subjects who tend to prefer solitary activities, more focused on their thoughts, feelings and moods than on the search for external stimuli.
Research also suggests a relationship between depressive disorder and a low score on conscientiousnesscharacteristic of individuals without objectives, informal, lazy, careless, undisciplined and with little will.
They also play against us -and are predictors of depression- the excess of self-criticism (inclination to feelings of guilt and failure derived from unrealistically high expectations of oneself) and dependency/sociotropia (feelings of helplessness and fears of abandonment resulting from a high emotional dependence on others).
Another attitude that promotes depression is what is known as negative attributional style. It is the tendency to explain the negative results of their experiences by internal, stable and global causes. For example, “I didn’t get the job because I’m useless, I always have been, in all facets of my life”, and similar thoughts.
Something similar happens with the ruminationdefined as the repetitive thought that focuses attention on depressive symptoms and their implications, causes and meanings in the person who experiences them.
Finally, the deficit personal resources (social skills, appropriate problem-solving strategies or coping skills in stressful circumstances) is also related to a higher risk of depressive symptoms.
adverse experiences
More than 40 years of research have documented the role played by serious life events at the onset of depression. Depending on the type of sample under study, approximately 50% to 80% of people with depression reported an acute and severe life event before the onset of the disorder.
Based on a conservative estimate, we could establish that people with depression are 2.5 times more likely to have experienced a serious life event before its onset compared to those who do not. Typically life-threatening health problems, separation and bereavement, exposure to violence, job loss, and financial insecurity.
Equally important is to consider the cataclysmic events or phenomena. That is, sudden, unique and powerful events that affect large numbers of people, which are often beyond the control of individuals or groups, and which are assumed to be universally stressful. Like the covid-19 pandemic.
exposure to negative events in childhood it also puts us at risk for depression as we grow older. These events include physical and sexual abuse, psychological neglect (or abandonment), exposure to domestic violence, parental mental illness, and criminality.
People with a history of childhood trauma (especially being a victim of bullying and mistreatment or emotional neglect during childhood) have more than twice the risk of developing depression.
comorbidity
Probably one of the most surprising aspects of depression is that it is often accompanied by other mental disorders. In particular, anxiety disorders, substance-related disorders, eating disorders, and sleep problems.
On the other hand, the chronic or serious medical illness is a risk factor for depression. Furthermore, an interrelation between depression and a large number of physical illnesses has been found: acute myocardial infarctionasthma, cancers, cardiac arrhythmia, chronic coronary syndrome, chronic obstructive pulmonary disease, congestive heart failure, some neurological diseases such as Alzheimer’s or epilepsy, thyroid problems, diabetes, obesity, some pathologies of the digestive system, hypertension, osteoarthritis, osteoporosis, kidney failure, rheumatoid arthritis, stroke… Without forgetting fibromyalgia and chronic fatigue.
Taking all of these factors into account can help prevent, but also help you better understand, depression. And perhaps it will allow us to stop his feet in his unstoppable advance.
Fernando Lino Vazquez GonzalezProfessor of Clinical Psychology, University of Santiago de Compostela
This article was originally published on The Conversation. read the original.
