Causes of Depression: Nature and Nurture
The causes of depression are wide and varied, but can be loosely grouped into nature (biological theories) and nurture (behavioural theories)
The causes of depression might be the most rigorously investigated aspect of any mental health condition. For centuries, psychologists and medical researchers have conducted studies attempting to define the factors that cause people to become depressed.
While no single cause has ever been discovered, a huge range of factors have been found to make us more likely to become depressed. These risk factors can be loosely split into two categories: nature and nurture.
Nature: The genetic predisposition
Causes of depression that are decided before we are born are grouped into the nature category. These have mostly been identified from studies on the brain and DNA in humans and animals, known as biological studies.
Biological risk factors for depression include being genetically predisposed and having chemical imbalances in the brain.
An imbalance of serotonin is the most notable chemical associated with depression, but there are loads of different factors that influence how individuals react to this.
If family members have a history of depression, you are more likely to carry one or more genes associated with the illness – but those specific genes have not been formally identified by research.
Gender is also an interesting biological risk factor, with women being significantly more likely to inherit depression than men.
Biological theories of depression also include evolutional theories, which suggest we evolved to have sad feelings to survive, and that depression is an over-evolved version of this trait.
Nurture: The upbringing factor
Environmental risk factors, which are established after we are born, belong to the nurture perspective of depression’s causes. These have been identified from studies on behaviour, so are part of the group of behavioural theories of depression.
Behavioural causes of depression include an abusive, neglectful or otherwise traumatic past, learned behaviours such as a depressed parent and environmental factors such as stress – both mental and physical.
The cognitive-behavioural theory of depression argues that it appears when individuals continuously attribute negative life events internally and process them negatively.
Other behavioural theories of depression include psychodynamic theories, Freud’s being the most famous of these. Freud’s psychodynamic theory attributes the cause of depression to fixations on certain stages of development in childhood.
Nature/Nurture: No Longer a Debate
Until this century, many studies attempted to prove that the causes of depression were entirely due to either nature or nurture. Scientists were strongly divided, and people spent their whole careers dedicated to proving a single theory.
Since then, multiple studies have proven that there is no one cause. Nature and nurture work together to shape each part of every individual – including their mental health. By understanding how both factors play a role, we are open to more effective treatments.
The reason for blue: depression and its causes
When it comes to depression, there is no one clear cause. While one child of a depressed parent might appear to inherit the disorder, another might live their whole life depression-free.
The main thing to remember is that all risk factors interact with one another. It also might be true that the more risk factors a person has, the more likely they are to develop depression.
The silver lining of the multiple, varied causes of depression is the multiple, varied treatment options. We will focus on that in two weeks, but next week we will cover what to do if you think a loved one might be depressed, including crisis intervention.
Felicity Thompson
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