The definition of depression is a condition which negatively affects how you feel, the way you think, and how you manage daily activities such as sleeping, eating and working.

Depression affects 1 in 20 Australians each year. It is not just a low mood, it is a serious medical condition that can affect both your physical and mental health.

Ted talk on depression

Types of depression

There are five main types of depression which range from mild to severe.

The different types of depression have specific symptoms which can be assessed by your GP or psychiatrist to determine the best treatment options.

Major depressive disorder (MDD)

This is the most common type of depression in Australia. It can be mild, moderate or severe depending on the intensity of the symptoms and how much they impact day-to-day life. There are several symptoms including a depressed mood and loss of interest or pleasure in normal activities.

Major depressive disorder with melancholia

This is a severe form of depression defined by a complete loss of pleasure in almost everything, feelings of despair, excessive guilt and a slowing down of movement or restlessness.

Psychotic depression

This is a type of depression where MDD is associated with hallucinations, paranoia and delusions. Although it is less common than other forms of depression, it is severe and often requires a combination of treatments.

Antenatal and postnatal depression

Pregnancy and after the birth of a baby can be a challenging time, with different demands and hormones. Approximately 15-20% of Australian women experience depression during pregnancy or in the year after giving birth. It is common for women to feel down, tired or irritable in the days and weeks after having a baby. A persistent low mood may be depression and can affect the mother and her relationship with the baby, partner and other members of the family.

Persistent depressive disorder

The persistent depressive disorder depression definition is feeling down for more than 2 years. Because the depression symptoms have been present for a long time, people may not realise they have depression and so may not seek help until encouraged to do so by a friend or family member.

Causes of depression

Depression can be caused by different factors


People who have close family members with depression are more likely to develop depression. No single gene has been identified yet that causes depression, it is likely to be caused by several genes.

Brain chemistry

neurotransmitters such as serotonin, dopamine and noradrenaline. These chemicals help the brain to send and receive messages.


Having a major or long-term illness is stressful and can lead to depression. Some medications that are used to treat an illness may also cause depression.

Personality traits

Having a personality trait such as low self-esteem, being a perfectionist, being self-critical or overly sensitive to criticism can make you more likely to develop depression.

Stress and traumatic events

Recent stressful events like losing a job or loved one can lead to depression as can long-term stress such as abusive


TMS is an effective treatment for depression, regardless of age, the duration of illness, the number of medications tried, or even gender