Southern Cross Medical Library

Please note, Southern Cross Medical Library information is necessarily of a general nature. Always seek specific medical advice for treatment appropriate to you.

<< Go to Medical Library index page

Depression - causes, symptoms, diagnosis, treatment

It is normal to experience periods of feeling down, often in response to the stresses of everyday living.  However, when a low mood is present for several weeks or more, it may be the result of depression.
Depression is generally characterised by feeling down most of the time or having little interest or pleasure in doing things.  Depression is a recognised mental health disorder with biological, pyschological and social components to its causes, symptoms and treatment.  Seeking treatment as early as possible is an important step in overcoming depression.


Depression can be triggered by different things in different people. Sometimes there is no clear cause for the depression. Factors that can increase a person’s risk of developing depression include:
  • Having had depression in the past
  • A family history of depression
  • Serious loss or stress, such as the death of a partner, close family member or friend; unemployment; divorce or relationship difficulties
  • Biological factors such as vitamin deficiencies or endocrine disorders
  • Some medications, such as blood pressure lowering medications and anti-migraine medications
  • Chronic illness – approximately 25% of people with a severe chronic illness such as Crohn's disease, diabetes or heart disease will develop depression
  • Some women are more likely to experience depression after childbirth. This is known medically as post-natal or postpartum depression. The likelihood of post-natal depression developing is increased if other risk factors are also present.
Excessive alcohol or the use of recreational or party drugs can make depression worse.  It is estimated that one in six New Zealanders will be affected by depression at some point in their life.  It can occur at any age and is diagnosed more commonly in women than men.

Signs and symptoms

Symptoms of depression vary between individuals and each person will have a different experience of the condition.  In general, the most common signs of depression (including post-natal depression) are:
  • Feeling down, depressed or hopeless.
  • Having little interest or pleasure in doing things (anhedonia).
  • Early morning awakening (occurs in 90% approximately)
Other symptoms of depression include:
  • Irritability/mood swings
  • Tearfulness
  • Low self-esteem/low motivation
  • Difficulty concentrating
  • Reduced sex drive (libido)
  • Feelings of emptiness or loneliness
  • Anxiety
  • Thoughts of hopelessness or death
Physical symptoms of depression include:
  • A pounding heart
  • Stomach cramps
  • Loss of energy
  • Significant weight loss or weight gain
  • Fatigue
  • Sleep problems
  • Changes in appetite.
Children and young people with depression can exhibit symptoms such as:
  • Anger and aggression
  • Risk-taking behaviours
  • Significant mood swings
  • Social isolation
  • Being quiet and shy
  • Denying that something is wrong.
People with depression also have a greater chance of developing panic attacks and phobias.


If depression is suspected, it is important to see a doctor so that an accurate diagnosis can be made and appropriate treatment given.
There is no medical test that can diagnose depression.  However, doctors use documented criteria to help diagnose the condition.
Blood tests to check for underlying conditions or deficiencies (eg, hypothyroidism) may be recommended.


The earlier treatment for depression is started, the better the chances of successful treatment. Carefully following the prescribed treatment plan is also vital in treating depression and preventing its recurrence.
Treatment of depression will be tailored to each individual and will involve a number of important components. The needs of the individual, and the stage and severity of the depression will be taken into account when planning treatment. The three main treatment approaches for depression are self-help techniques, psychological therapies and medications.
Self-help techniques:
Self-help techniques that can help combat depression include: 
  • Regular exercise
  • Maintaining a healthy, balanced diet
  • Reducing alcohol, caffeine and tobacco intake
  • Having a regular bedtime and waking up time
  • Recognising when time out is needed, and taking it
  • Making time to undertake an enjoyable activity each day
  • Asking for and/or accepting support from friends and families to achieve self-help goals.
Complementary therapies may also prove beneficial for some people. There are a variety of complementary and alternative therapies available including massage, hypnotherapy, acupuncture, yoga, dietary supplements and herbal remedies (eg: St John’s wort). It is important to discuss the use of herbal remedies with your doctor before using them as they may interfere with other treatments or medications.
Psychological therapies:
This is essentially ‘talking therapy’ and may be recommended alone in cases of mild depression. In cases of moderate and severe depression, it may be recommended in addition to antidepressant medications.
There are a number of different psychological therapy techniques. Examples of therapies that are useful in treating depression include cognitive behavioural therapy (CBT), interpersonal psychotherapy (ITP) and problem-solving therapy.
CBT involves helping a person to change negative ways of thinking and behaving that are associated with their depression.  IPT focusses on a person's dysfunctional personal relationships that cause depression or make the depression worse.
Antidepressants are the mainstay medications for depression. However, other medications such as anti-psychotics and sedatives may be used in conjunction with antidepressant medications in some cases. As it is difficult to predict how a person will respond to and tolerate a particular antidepressant medication, a process of trial and error may be required until an effective medication for that person is found.
There are a number of different classes of antidepressant medications available in New Zealand.  In general, antidepressant medications work by increasing levels of natural chemicals in the brain that can affect a person’s mood. Two common brain chemicals (known as neurotransmitters) that affect the mood are serotonin and noradrenaline which tend to be reduced when a person has depression. The classes of antidepressant medications most commonly used in New Zealand are the ones that affect serotonin and noradrenaline levels.
Common antidepressant medications prescribed in New Zealand include fluoxetine, paroxetine, citalopram, venlafaxine and amitriptyline.  More information about each of these medications, including the brand names by which they're also known, can be found at
Antidepressant medications are not addictive.  However, they can cause unpleasant side effects if stopped suddenly. Antidepressant medications should only be discontinued while under the supervision of a doctor.
Electroconvulsive therapy (ECT):
Uncommonly, and only in cases of very severe depression where other treatments have been unsuccessful, electroconvulsive therapy (ECT) may be effective. This involves passing an electric current across the head after a muscle relaxant and general anaesthetic has been administered. The exact reason ECT is effective is not fully understood but it is thought to affect the chemical balance in the brain, leading to stabilisation of mood and reduction of depression.

Further information and support

Your GP or practice nurse can provide information and support about depression.
The following services can also provide support to people suffering from depression, as well as to their friends and family.
Depression Helpline
Freephone: 0800 111 757
Freephone: 0800 543 354
Freephone: 0800 37 66 33
Freephone: 0800 726 666
The Mental Health Foundation of New Zealand has information and resources (eg: videos, books) about depression.
Ph: (09) 300 7030


Dryden-Edwards, R. (2012) Depression. New York: WebMD LLC.
New Zealand Guidelines Group (2006) Depression: There is a way through it (PDF). Ministry of Health. Wellington.
New Zealand Guidelines Group. (2008) Identification of common mental disorders and management of depression in primary care (PDF). New Zealand Guidelines Group. Ministry of Health. Wellington.
O’Toole, M.T. (Ed.) (2013) Depression. Mosby’s Dictionary of Medical, Nursing & Allied Professions. St Louis: Elsevier Mosby.
The Mental Health Foundation of New Zealand (Date Unknown) Facts about depression (PDF). The Mental Health Foundation of New Zealand. Auckland

Fact Sheet Created - 23 June 2013 

Go to our Medical Library Index Page to find information on other medical conditions.