The core experiences of depression—changes in energy, activity, thinking, and mood—have been recognized for over 10,000 years. The term “depression” has been in use for about 350 years.
Despite this long history, experts disagree on what depression is, how to define it, and what causes it.
Many experts agree that depression isn’t a single entity. It encompasses a wide array of illnesses with different causes and mechanisms. This variety makes choosing the best treatment challenging.
One strategy is to search for subtypes of depression to determine if they respond differently to treatments. A common example is the distinction between “reactive” depression and “endogenous” depression.
Reactive depression, sometimes called social or psychological depression, is triggered by stressful life events, such as losing a loved one or being assaulted. Endogenous depression, also known as biological or genetic depression, is believed to be caused by internal factors like genes or brain chemistry.
Many clinicians accept this subtyping, but it may be too simplistic.
While stressful life events and genes can individually contribute to depression, they also interact to increase the risk of developing the condition. Moreover, there is evidence of a genetic component in being exposed to stressors. Some genes influence personality, affecting how we interact with our environment.
To examine the role of genes and stressors, a research team in the Australian Genetics of Depression Study surveyed people with depression about stressful life events. They analyzed DNA from their saliva samples to calculate their genetic risk for mental disorders.
The study explored whether people’s genetic risk for depression, bipolar disorder, schizophrenia, ADHD, anxiety, and neuroticism influenced their reported exposure to stressful life events.
They found people with a higher genetic risk for these conditions tended to report more stressful life events like assault, accidents, legal troubles, and childhood abuse and neglect.
These associations were not strongly influenced by age, sex, or family relationships. However, other factors like socioeconomic status were not considered, and the study relied on self-reported memory of past events, which may not be accurate.
The findings challenge the traditional reactive versus endogenous depression subtypes. They suggest that genes and environments interact in complex ways. The study indicates that most depression cases are a mix of genetics, biology, and stressors.
For those with higher genetic vulnerability, learning techniques to manage stress might be beneficial. This could potentially reduce the risk of developing depression and help those with depression manage ongoing stressors.
If this article has raised concerns or you need support, consider reaching out to a helpline like Lifeline at 13 11 14.
Jacob Crouse, Research Fellow in Youth Mental Health, Brain and Mind Centre, University of Sydney, and Ian Hickie, Co-Director, Health and Policy, Brain and Mind Centre, University of Sydney.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
