Basic experiences depression – changes in energy, activity, considering and mood – have been described for over 10,000 years. The word “depression” has been used for about 350 years.
Given this long history, it may surprise you to learn that experts I don’t agree what’s depression, how to define it and what causes it.
But many experts agree that depression is just not one case. It is a big family of diseases with different causes and mechanisms. This makes selecting the best treatment for every person a challenge.
Reactive depression and endogenous depression
One strategy is to search subtypes depression and see if they might recuperate results with various kinds of treatment. One example is the contrast between “reactive” depression and “endogenous” depression.
Reactive depression (also called social or psychological depression) is presented as being brought on by exposure to stressful life events. It may very well be an attack or the lack of a loved one – an comprehensible response to a trigger.
Endogenous depression (also called biological or genetic depression) is assumed to be brought on by something, akin to genes or brain chemistry.
Many people work clinically in mental health accept that is subtyping. You may have examine it online.
However, we consider that this approach is way too easy.
While stressful life events and genes may individually contribute to causing depression, in addition they influence depression increase the risk in someone who suffers from depression. And the evidence shows that it exists genetic component to exposure to stressors. Some genes influence things like personality. Some influence how we interact with our surroundings.
What we did and what we found
Our team decided to look at the role of genes and stressors to see whether the classification of depression as reactive or endogenous is correct.
In Australian Depression Genetics Study, people affected by depression responded to surveys about their exposure to stressful life events. We analyzed DNA from their saliva samples to calculate their genetic risk for mental disorders.
Our query was easy. Does genetic risk for depression, bipolar disorder, schizophrenia, ADHD, anxiety, and neuroticism (a personality trait) influence people’s reported exposure to stressful life events?
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You may be wondering why we bothered to calculate the genetic risk of mental disorders in individuals who already suffer from depression. Every person has genetic variants related to mental disorders. Some have more, some have less. Even individuals who already suffer from depression may have a low genetic risk. These people may have developed depression for a distinct constellation of causes.
We looked at the genetic risk of diseases aside from depression for several reasons. First, the genetic variants related to depression overlap with those related to other mental disorders. Secondly, two individuals with depression may have completely different genetic variants. So we wanted to forged a large net to look at a broader spectrum of genetic variants related to mental disorders.
If the subtypes of reactive and endogenous depression are correct, we would expect that individuals with a lower genetic component of depression (the reactive group) would report more stressful life events. We would expect that individuals with the next genetic component (endogenous group) would report fewer stressful life events.
However, after examining over 14,000 people affected by depression, we found the opposite.
We found that individuals with the next genetic risk of depression, anxiety, ADHD or schizophrenia, to which they claim to have been exposed more stressors.
Aggravated assault, sexual assault, accidents, legal and financial troubles, and childhood abuse and neglect were more common in individuals with an increased genetic risk of depression, anxiety, ADHD, or schizophrenia.
These associations weren’t significantly influenced by age, gender or relationships with family. We didn’t look at other aspects that may influence these associations, akin to socioeconomic status. We also relied on people’s memory of past events, which may not be accurate.
What role do genes play?
The genetic risk of mental disorders changes an individual’s sensitivity to the environment.
Imagine two people, one at high genetic risk for depression, the other at low genetic risk. They each lose their jobs. A genetically sensitive person perceives job loss as a threat to his or her value and social status. There is a way of shame and despair. They cannot force themselves to look for an additional job for fear of losing it too. On the other hand, job loss is less about them and more about the company. These two people internalize the event in another way and remember it in another way.
Genetic risk for mental disorders may increase the likelihood that people will find yourself in environments where bad things occur. For example, the next genetic risk for depression can impact self-esteem, increasing the risk of stepping into dysfunctional relationships that then end badly.
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What does our study mean for depression?
First, it confirms that genes and environments aren’t independent. Genes influence the environment we are in and what happens next. Genes also influence how we respond to these events.
Second, our study doesn’t support the distinction between reactive and endogenous depression. Genes and environments interact in complex ways. Most cases of depression they’re a mix genetics, biology and stressors.
Third, depressed people whose depression appears to have a stronger genetic component report having more severe stressors in their lives.
Thus, from a clinical perspective, individuals with greater genetic susceptibility may profit from learning specific stress management techniques. This may help some people reduce their risk of depression in the first place. It may also help some individuals with depression reduce their ongoing exposure to stressors.