Depression explained

While we all feel sad, moody or low from time to time, some people experience these feelings intensely, for long periods of time (weeks, months or even years) and sometimes without any apparent reason. Depression is more than just a low mood – it's a serious condition that has an impact on both physical and mental health.

Depression is common

In any one year, around one million people in Australia experience depression. One in six women and one in eight men will experience depression at some time in their life. The good news is, depression is treatable and effective treatments are available. The sooner a person with depression seeks support, the sooner they can recover.

Symptoms of depression

Depression affects how people think, feel and act. Depression makes it more difficult to manage from day to day and interferes with study, work and relationships. A person may be depressed if for more than two weeks they have felt sad, down or miserable most of the time or have lost interest or pleasure in most of their usual activities, and have also experienced several of the signs and symptoms across at least three of the categories in the list below. It’s important to note, everyone experiences some of these symptoms from time to time and it may not necessarily mean a person is depressed. Equally, not every person who is experiencing depression will have all of these symptoms.

Feelings caused by depression

A person with depression may feel:

• sad
• miserable
• unhappy
• irritable
• overwhelmed
• guilty
• frustrated
• lacking in confidence
• indecisive
• unable to concentrate
• disappointed.

Thoughts caused by depression

A person with depression may have thoughts such as:

• ‘I’m a failure.’
• ‘It’s my fault.’
• ‘Nothing good ever happens to me.’
• ‘I’m worthless.’
• ‘There is nothing good in my life.’
• ‘Things will never change.’
• ‘Life’s not worth living.’
• ‘People would be better off without me.’

Behavioural symptoms of depression

A person with depression may:

• withdraw from close family and friends
• stop going out
• stop their usual enjoyable activities
• not get things done at work or school
• rely on alcohol and sedatives.

Physical symptoms of depression

A person with depression may experience:

• being tired all the time
• feeling sick and ‘run down’
• frequent headaches, stomach or muscle pains
• a churning gut
• sleep problems
• loss or change of appetite
• significant weight loss or gain.

Causes of depression

While the exact cause of depression isn’t known, a number of things can be associated with its development. Generally, depression does not result from a single event, but from a combination of biological, psychological, social and lifestyle factors.

Personal factors that can lead to depression

Personal factors that can lead to a risk of depression include:

• family history – depression can run in families and some people will be at an increased genetic risk. However, this doesn’t mean that a person will automatically experience depression if a parent or close relative has had the condition.
• personality – some people may be more at risk because of their personality, particularly if they tend to worry a lot, have low self-esteem, are perfectionists, are sensitive to personal criticism, or are self-critical and negative
• serious medical conditions – these can trigger depression in two ways. Serious conditions can bring about depression directly or can contribute to depression through the associated stress and worry, especially if it involves long-term management of a condition or chronic pain
• drug and alcohol use – can both lead to and result from depression. Many people with depression also have drug and alcohol problems.

Life events and depression

Research suggests that continuing difficulties, such as long-term unemployment, living in an abusive or uncaring relationship, long-term isolation or loneliness or prolonged exposure to stress at work can increase the risk of depression.

Significant adverse life events, such as losing a job, going through a separation or divorce, or being diagnosed with a serious illness, may also trigger depression, particularly among people who are already at risk because of genetic, developmental or other personal factors.

Changes in the brain

Although there has been a lot of research in this complex area, there is still much that we do not know. Depression is not simply the result of a chemical imbalance, for example because a person has too much or not enough of a particular brain chemical. However, disturbances in normal chemical messaging processes between nerve cells in the brain are believed to contribute to depression.

Some factors that can lead to faulty mood regulation in the brain include:

• genetic vulnerability
• severe life stressors
• taking some medications, drugs and alcohol
• some medical conditions.

Most modern antidepressants have an effect on the brain’s chemical transmitters, in particular serotonin and noradrenaline, which relay messages between brain cells. This is thought to be how medications work for depression.

Other medical treatments such as transcranial magnetic stimulation (TMS) and electroconvulsive therapy (ECT) may sometimes be recommended for people with severe depression who have not recovered with lifestyle change, social support, psychological therapy and medication. While these treatments also have an impact on the brain’s chemical messaging process between nerve cells, the precise ways in which these treatments work is still being researched.

Seek support for symptoms of depression

Depression is often not recognised and can go on for months or even years if left untreated. It’s important to seek support as early as possible, as the sooner a person gets treatment, the sooner they can recover.

Untreated depression can have many negative effects on a person’s life, including serious relationship and family problems, difficulty finding and holding down a job, and drug and alcohol problems.

There is no one proven way that people recover from depression. However, there is a range of effective treatments and health professionals who can help people on the road to recovery.

There are also many things that people with depression can do for themselves to help them recover and stay well. The important thing is to find the right treatment and the right health professional for a person’s needs.

Types of depression

There are different types of depression. The symptoms for each can range from relatively minor through to severe.

Major depression

Major depression, or major depressive disorder is the technical term used by health professionals and researchers to describe the most common type of depression. Other terms sometimes used include unipolar depression or clinical depression.

Depression can be described as mild, moderate or severe.

Melancholia

Melancholia is an older term for depression and is still sometimes used to describe a more severe form of depression with a strong biological basis, where many of the physical symptoms of depression are particularly evident. For example, one of the major changes is that the person can be observed to move more slowly, or to be experiencing significant changes to their sleep pattern and appetite.

A person with melancholia is also more likely to have a depressed mood that is characterised by complete loss of pleasure in everything or almost everything.

Dysthymia

The symptoms of dysthymia (sometimes called Persistent Depressive Disorder) are similar to those of major depression, but are less severe and more persistent. A person has to have this milder depression for more than two years to be diagnosed with dysthymia.

Psychotic depression

Sometimes, people with a depressive condition can lose touch with reality. This can involve hallucinations (seeing or hearing things that are not there) or delusions (false beliefs that are not shared by others), such as believing they are bad or evil, or that they are being watched or followed or that everyone is against them. This is known as psychotic depression.

Antenatal and postnatal depression

Women are at an increased risk of depression during pregnancy (known as the antenatal or prenatal period) and in the year following childbirth (known as the postnatal period). This time frame (the period covered by pregnancy and the first year after the baby’s birth) may also be referred to as the perinatal period.

The causes of depression at this time can be complex and are often the result of a combination of factors. In the days immediately following birth, many women experience the ‘baby blues’, which is a common condition related to hormonal changes, affecting up to 80 per cent of women who have given birth.

The ‘baby blues’, or the general stress of adjusting to pregnancy or a new baby, are common experiences, but are different from depression.

Depression is longer lasting and can affect not only the mother, but her relationship with her baby, the child’s development, the mother’s relationship with her partner and with other members of the family.

Up to one in 10 women will experience depression during pregnancy. This increases to 16 per cent in the first three months after having a baby.

Bipolar disorder

Bipolar disorder used to be known as ‘manic depression’ because the person experiences periods of depression and periods of mania with periods of normal mood in between. The symptoms of mania are opposite to the symptoms of depression and can vary in intensity. They include:

• feeling great
• having plenty of energy
• racing thoughts
• little need for sleep
• talking fast
• having difficulty focusing on tasks
• feeling frustrated and irritable.

This is not just a fleeting experience. Sometimes, the person loses touch with reality and experiences hallucinations or delusions, particularly about their ideas, abilities or importance. A family history of bipolar disorder can increase a person’s risk of experiencing bipolar disorder.

Because bipolar disorder includes periods of depression, it is not uncommon for a person with bipolar disorder to be misdiagnosed as having major depression until they have a manic or hypomanic episode. Bipolar disorder can also sometimes be confused with other mental health conditions such as schizophrenia.

The treatment for bipolar disorder is often different to that for major depression. It is therefore important to check for this condition whenever a person is being assessed for depression.

Cyclothymic disorder

Cyclothymic disorder is an uncommon condition which is often described as a milder form of bipolar disorder. The person experiences chronic fluctuating moods over at least two years, involving periods of hypomania (a mild to moderate level of mania) and periods of depressive symptoms, with very short periods (no more than two months) of normality between.

The symptoms last for a shorter time, are less severe, and are not as regular, so they don’t fit the criteria of bipolar disorder or major depression.

Seasonal affective disorder (SAD)

SAD is a mood disorder that has a seasonal pattern. The cause is unclear, but may be related to the variation in light exposure in different seasons. SAD is characterised by mood disturbances (either periods of depression or mania) that begin and end in a particular season. Depression in winter only is the most common way in which people experience SAD.

SAD is usually diagnosed after the person has had the same symptoms during winter for two or more years. People with SAD are more likely to experience lack of energy, sleep too much, overeat, gain weight and crave carbohydrates.

SAD is rare in Australia, and more likely to be found in countries with short days and longer periods of darkness, such as the cold climate in the Northern Hemisphere.

Where to get help

• Your GP (doctor)
• Your local community health centre
• beyondblue Tel. 1300 22 4636
• Lifeline Tel 13 11 14
• Kids Helpline Tel 1800 55 1800
• SuicideLine Victoria Tel 1300 651 251
• SANE Australia Helpline Tel. 1800 187 263
• Australian Psychological Society Find a psychologist service Tel. 1800 333 497 (outside Melbourne) or (03) 8662 3300 (in Melbourne)
• Mind Australia Tel. 1300 AT MIND (1300 286 463)