Causes of depression

Depression has many causes.

Over the years, research has shown a few factors that are linked with its development, often triggered by events of the present and personal events of the past. It is important to understand that depression grows into a person over a period of time and is not always the result of an immediate event.

What are the causes of depression?

15% of Australians aged 16 to 85 have experienced an affective disorder. This is equivalent to 2.83 million people today.

Depression is caused by several factors that are linked together. It's important to note that depression does not happen overnight, the causes would have been building up over a period of time. Depression results from a combination of long-term factors like personal issues or problems, though it is possible for one single event to trigger depression. 

The likely combination of events to trigger depression are:

Life events

Stressful situations like an abusive relationship, tough working conditions, prolonged unemployment are some of the long-term factors that contribute to depression. Recent events like the passing of a loved one or losing a job can trigger the depression.


Trauma permanently alters the brain at the cellular level, especially in key areas of the brain that handles stress. Studies have shown that those suffering from a traumatic incident tend to have higher levels of ACTH and cortisol in their brain.

Prolonged stress

When there is a perceived threat to our well-being, the body triggers a series of actions that force us to adapt to the situation by releasing a hormone called CRH. Changes in the body include accelerated heart rate and faster breathing. If the changes are temporary, then the body returns to normal. But if the feeling is prolonged then it can affect both the body and mind leading to problems like depression. Studies show that people suffering from depression and dysthymia often have higher levels of CRH.

Biological factors

Neuro-chemical balance and its contributing factors as a cause of depression is still a widely debated topic. One reason is that the role of the brain in depression is incredibly complex as it’s not as simple as a ‘chemical imbalance’ - having too much of one chemical and not enough of another. The other reason is that the brain regulates the flow of neuro-chemicals depending on several factors like our mood, life "stressors", alcohol intake and drug consumption.

Poor diet       

Research shows that a deficiency of vitamins and minerals can affect your mental health, making you more vulnerable to depression than before. If you are short on Omega-3 fatty acids and there is an imbalance between Omega- and Omega-3, this can be one of the contributing factors behind depression.                                                    

Circadian Rhythm Disturbance

A disturbance in the circadian rhythm is likely to cause depression, particularly SAD. The circadian rhythm is disrupted when less light enters the eye. While this particular cause may not be significant to individuals in Australia, it is prevalent in countries where winter months see less day time for significant portions of the year.

Personal events

Drug and alcohol use: Collectively known as substance abuse, over 500,000 Australians will experience substance abuse at some point in their lives. Substance abuse is both the cause and a symptom of depression.

Personality: Certain personality traits will make people more prone to depression than others. Traits include but are not restricted to:

  • Perfectionism
  • Low-self esteem
  • Self-critical
  • Sensitive
  • Negative

Medical issues: The stress and worry of having to deal with chronic pain causes depression. Coping with the illness can be a huge burden especially when there is no adequate support system.

Family history: If you have a relative who suffered from depression then that puts you at higher risk. However, genetic disposition alone does not cause depression - social factors are still a major contributing factor.

 Types of depression

Learn about the different types of depression

Signs and symptoms of depression

Understand the indicators of depression

Get through your struggle with depression

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