Depression can run in families and some people will be at an increased genetic risk.
Having a parent or close relative with depression doesn’t mean you’ll automatically have the same experience. Life circumstances and other personal factors are still likely to have an important influence.
Some people may be more at risk of depression because of their personality. Risk factors include:
- tendency to worry a lot
- low self-esteem
- sensitivity to personal criticism
- self-criticism and negativity.
Serious medical illness
The stress and worry of coping with a serious illness can lead to depression, especially if it’s long-term or you’re dealing with chronic pain.
Drug and alcohol use
Drug and alcohol use can lead to depression. Many people with depression also have drug and alcohol problems.
Over 500,000 Australians will experience depression and a substance use disorder at the same time, at some point in their lives.
Research suggests that continuing difficulties are more likely to cause depression than recent life stresses. This can include:
- long-term unemployment
- living in an abusive or uncaring relationship
- long-term isolation or loneliness
- prolonged work stress.
Recent events (such as losing your job) or a combination of events can ‘trigger' depression if you’re already at risk because of previous bad experiences or personal factors.
Changes in the brain
A lot of research has been done into this complex area, but there’s still a lot we don’t know.
Depression isn’t simply the result of a ‘chemical imbalance’, like having too much or not enough of a particular brain chemical.
The way your brain regulates your moods can be affected by:
- genetic vulnerability
- severe life stressors
- some medications, drugs and alcohol
- medical conditions.
Most modern antidepressants affect your brain’s chemical transmitters (serotonin and noradrenaline), which relay messages between brain cells. This is thought to be how medications work for more severe depression.
Psychological treatment can also help you to regulate your moods.
Effective treatment can stimulate the growth of new nerve cells in circuits that regulate your mood. This may help you recover from severe depression.
Learn more: Treatments for depression.