The following information about the causes of depression comes from
http://www.blackdoginstitute.org.au/public/depression/causesofdepression/index.cfm
BIOCHEMICAL
Our knowledge of the human brain is still fairly limited, therefore we do not really know what actually happens in the brain to cause depression.
It’s likely that with most instances of clinical depression, neurotransmitter function is disrupted. Neurotransmitters are chemicals that carry signals from one part of the brain to the next. There are many neurotransmitters, serving different purposes, however three important ones that affect a person’s mood are serotonin, noradrenaline and dopamine.
In normal brain function, neurotransmitters jump from one nerve cell to the next, with the signal being as strong in the second and subsequent cells as it was in the first. However, in people who are depressed, the mood regulating neurotransmitters fail to function normally, so that the signal is either depleted or disrupted before passing to the next nerve cell.
In all depressions, it is likely that the transmission of serotonin is reduced or disrupted, whereas in people with melancholic and psychotic depression, other neurotransmitter pathways such as those for noradrenaline and dopamine are also likely to be functioning abnormally.
GENETICS
While depression is popularly considered to be due to life experiences and/or personality factors, there is in fact, strong evidence for significant genetic predisposition towards developing depression.
Studies of twins have confirmed that depression can be inherited. The genetic risk of developing clinical depression is about 40%, with the remaining 60% being due to factors in the individual’s own environment. Depression is unlikely to occur without life events, but the risk of developing depression as a result of some such event is strongly genetically determined. It is unlikely that any one contributing gene will be identified.
While the genetic risk to depression is now being clarified, the specific genes and traits inherited are yet to be identified. It may be that some of the genetic risk is to melancholic depression and, as well, to certain personality ‘styles’ that increase the chance of developing non-melancholic depression.
Relevant to this, there have been a number of reports of genes associated with particular personality characteristics. For example, genes have been identified that seem to be associated with novelty-seeking behaviour, and others that are linked to high anxiety levels (e.g the short arm of the SEROTONIN TRANSPORTER gene).
Though the genetics of depression are complex and progress is be expected to be slow, identification of genes that predispose a person to depression is a strong and growing area of research.
STRESS
It is important to recognise that nearly every individual can be stressed and depressed by certain events. Most people experience a rapid ‘spontaneous’ resolution within days or weeks. Some do not – so that the depression persists – with the ‘stress’ either maintaining the process or having initiated processes that will not simply be resolved by ‘the passage of time’.
Past and long-standing stresses (called distal stressors) can increase the chance of an individual developing depression in later years. The most clearly established past stressor is that of an uncaring parent or an abusive parent. The lack of parental care may result in the child developing a low self-esteem and thus being vulnerable to develop depression in adult life. The death of a parent in childhood does not appear to be a distinct stressor – it may cause depression at the time but it does not necessarily lead to depression in adulthood in any direct way.
Most individuals who develop non-melancholic depression usually describe an important and understandable life event that occurred before the depression started. The events that are most likely to ‘trigger’ depression are ones where the individual’s self-esteem is put at risk, compromised or devalued. For most adults, self-esteem is closely linked to an intimate relationship as well as in other important areas, such as a job. Thus, the break-up of a relationship or a marriage or loss of job are a very common triggers for depression. Other individuals develop depression when they feel a sense of ‘shame’, such as when they feel that they have not lived up to their own or others’ expectations, thus reducing their self-esteem. Identifying and understanding the meaning of the life event stressor can be all-important in assisting the individual to recover from the episode. The impact of life events upon melancholic depression is not always clear. They may serve to may trigger the depression – or rekindle it – rather than cause it.
Stress contributes to depression either by:
- Its severity – so that you may feel under ‘too much stress’ – in which case stress management programs (such as our myCompass program) may be helpful; or
- Its ‘salience’ or particular meaning to you – so that a particular event or set of circumstances is likely to trigger stress in you and may do so repeatedly if re-exposed to those triggers – in which case it can be helpful to seek sophisticated counselling or psychotherapy to identify what those triggers are and why they produce the stress reaction
1. What are the signs of depression?
The following are a list of the features that may be experienced by someone with depression.
- Lowered self-esteem
- Change in sleep patterns
- Change in mood control
- Varying emotions throughout the day
- Change in appetite and weight
- Reduced ability to enjoy things
- Reduced ability to tolerate pain
- Reduced sex drive
- Suicidal thoughts
- Impaired concentration and memory
- Loss of motivation and drive
- Increase in fatigue
- Change in movement
- Being out of touch with reality.
Note that, having one or other of these features, by themselves, is unlikely to indicate that someone is clinically depressed. Also, having these features for only a short period (of less than two weeks) is unlikely to indicate clinical depression. It’s also important to know that many of the above features could be caused by or related to other things, such as a physical illness, the effects of medications, or stress. Help in coming to such decisions should be assisted by a proper assessment by a trained professional.
2. How depressed should I be before I seek help?
Everybody feels down or sad at times. But it’s important to be able to recognise when depression has become more than a temporary thing, and when to seek help.
As a general rule of thumb, if your feelings of depression persist for most of every day for two weeks or longer, and interfere with your ability to manage at home and at work or school, then a depression of such intensity and duration may require treatment, and should certainly benefit from assessment by a skilled professional.
3. What should I do if I’m feeling (or someone close to me is feeling) suicidal?
- See the list of emergency contact numbers (and add the numbers of your General Practitioner and your local Community Mental Health Service) and keep a copy handy somewhere. Don’t hesitate to call one of them if in need of help
- Recognise that having suicidal thoughts is one of the features of depression, and seek help, either from your General Practitioner or another mental health professional such as a psychologist or a counsellor. Make sure you tell them you have been having suicidal thoughts
- If you have already received treatment for depression, and you are having suicidal thoughts, contact the person who has been giving you the treatment, or a close friend who you trust, and tell them you are feeling suicidal
- If someone close to you is suicidal or unsafe, talk to them about it and encourage them to seek help. Help the person to develop an action plan, involving him or her and trusted close friends or family members, to keep him or her safe in times of emergency
- Take away risks, make sure you or the person who are concerned for is in a safe environment.
4. Am I always going to feel like this?
This is a common fear. It’s important to know that it will pass. Depression can be successfully treated and that you will feel better in time and with the right treatment.
5. How long doe depression last?
Sometimes depression goes away of its own accord, but, depending on the nature and type of the depression, it may take many months and possibly considerable suffering and disruption if left untreated. Allow yourself to seek help in the same way you might if you had a physical illness.
6. How is depression treated?
There are a large number of different treatments for depression. At the Black Dog Institute we believe that different types of depression respond best to different treatments and it is therefore important that a thorough and thoughtful assessment be carried out before any treatment is prescribed.
Treatments can fall into the following categories:
Physical treatments, comprising :
- drug treatments, of which there are three main groups: antidepressants, tranquillisers, and mood stabilizers.
- electroconvulsive therapy (ECT) – a physical therapy that may be relevant in a minority of cases of psychotic depression, severe melancholia or life-threatening mania.
- transcranial magnetic stimulation – a treatment that is still under development, but which involves holding a coil near to a patient’s head and creating a magnetic field to stimulate relevant parts of the brain.
Psychological treatments, the most common ones being:
- Cognitive Behaviour Therapy – a form of therapy that aims to show people how their thinking affects their mood and to teach them to think in a less negative (and more ‘realistic’) way about life and themselves.
- Interpersonal Therapy – a therapy that aims to help people understand how social functioning (work, relationships and social roles) and personality operate in their lives to affect their mood.
- Psychotherapy – an extended treatment aimed at exploring aspects of the person’s past in great depth to identify links to the current depression.
- Counselling – a broad set of approaches and goals that provide problem solving and learning skills to cope with difficult life circumstances.
7. Where can I get help for depression?
A good first place to start in getting help is to visit your local General Practitioner. Let him or her know if you think you might have depression. Your General Practitioner will either conduct an assessment of you to find out whether you have depression, or refer you to someone else, such as a psychiatrist or a psychologist.
Depending on the nature of your depression, your General Practitioner may recommend some psychological intervention, such as cognitive behaviour therapy or interpersonal therapy, and might prescribe antidepressant medication to relieve some of the symptoms of depression.
Because depression is a common experience these days, many General Practitioners are used to dealing with depression and other mental health problems. Some General Practitioners take a special interest in mental health issues and undergo additional training in the area. If you don’t feel comfortable talking to your own doctor, find another one with whom you do feel comfortable. It is important that you feel comfortable talking about how you are feeling with your doctor so they have as much information to help you as possible.
If you are having trouble tracking down such a General Practitioner, you could telephone general practices in your area to find out whether any doctors in that practice have a particularly strong interest in mental health and, if so, whether they are taking on new patients. (Ask to speak to the practice manager.)
Psychologists, psychiatrists and counsellors are other professionals trained to provide help for depression and mood disorders. You will need a referral from your doctor to see a psychiatrist (and this will either eliminate or reduce costs).
Social workers, occupational therapists and registered nurses are also trained in mental health.
Find out more about consulting a professional.
8. How should I behave with someone who is depressed?
Someone with a depressive illness is like anyone with an illness – they require our care. You can provide better care if you are able to:
- Understand something about the illness
- Understand what the treatment is, why it is being given, and how long the person is expected to take to recover.
An important part of caring is to help the treatment process:
- If medication is prescribed encourage the person to persist with treatment (especially when there are side effects)
- Counselling or psychotherapy often results in the depressed person ‘thinking over’ their life and relationships. While this can be difficult for all concerned, you should not try and steer the person away from these issues.
- A resolving depression sometimes sees strong emotions released which may be hard on the carer. The first step in dealing with these fairly is to sort out which emotions really refer to the carer and which refer to other people or to the person themselves.
- Treatment has a positive time as well – when the person starts to re-engage with the good things in life and carers can have their needs met as well.
Don’t forget that as a carer you too are likely to be under stress. Depression and hopelessness have a way of affecting the people around them. Therapy can release difficult thoughts and emotions in carers too. So part of caring is to care for your own self – preventing physical run-down and dealing with the thoughts and emotions within yourself.