Depression

Simply being somewhat pessimistic or negativistic does not necessarily mean that you are experiencing depressive illness. The tendency to be pessimistic or negative is often encoded at personality level and does not necessarily affect mood or generate depressive illness but can be symptomatic of depressive illness.

The confusion is made all the worse because it is often difficult to tell the difference between feeling gloomy and having a depressive illness. Doctors make a diagnosis of depression after assessing the severity of the low mood, other associated symptoms and the duration of the problem.

Depression is very common. Almost anybody can develop the illness; it is certainly NOT a sign of weakness. Depression is also highly treatable. You may need to see a doctor, but there are things you can do yourself or things you can do to help somebody suffering from the illness. What you cannot do is 'PULL YOURSELF TOGETHER' - no matter whether this is what you think you should be able to do, or what other people tell you to do.

People who have experienced an episode of depression are at greater risk of developing another in the future. A small proportion may experience an episode of depression as part of a bipolar affective disorder (manic depression) that is characterised by episodes of both very low and very high moods.

Are humans naturally over optimistic?

Past research (eg University of Kansas 2009) has suggested that human beings are naturally quite optimistic about negative outcomes in our future (known as optimism bias theory). However, more recent research from King's College London / Birkbeck / University College London from 2016 titled "A pessimistic view of optimistic belief updating" casts doubt on this conclusion. They suggest that the process is highly contextually dynamic and shows no particular universal bias towards optimism. This perhaps explains why many people struggle when trying to be more optimistic, for instance when considering the impact of climate change, yet can be highly optimistic about other aspects of their lives.

Who gets depressed?

Depression is very common. Between 5 and 10 per cent of the population are suffering from the illness to some extent at any one time.

Over a lifetime you have a 20 per cent, or one in five, chance of having an episode of depression.

Women are twice as likely to get depression as men.

Bipolar affective disorder is less common than depressive illness with a life-time risk of around one to two per cent. Men and women are equally affected.

Getting depression is NOT a sign of weakness. There are no particular 'personality types' that are more at risk than others. However, some risk factors have been identified, these include inherited (genetic) factors, such as having parents or grandparents who have suffered from depression and non-genetic factors such as the death of a parent when you were young.

What causes depression?

We do not fully understand the causes of depression.

Genes or early life experiences may make some people vulnerable.

Stressful life events, such as losing a job or a relationship ending, may trigger an episode of depression. As may a string of lesser life events.

Depression can be triggered by some physical illnesses, drug treatments and recreational drugs.

It is often impossible to identify a 'cause' in many people and this can be distressing for people who want to understand the reasons why they are ill. However depression, like any illness, can strike for no apparent reason.

It is clear that there are definite changes in the way the brain works when a person is depressed:

Modern brain scans that can look at how 'hard' the brain is working have shown that some areas of the brain (such as at the front) are not working as well as normal.

Depressed patients have higher than normal levels of stress hormones.

Various chemical systems in the brain may not be working correctly including one known as the serotonin or 5-HT system.

Antidepressants may help to reverse these changes.

Symptoms of depression

• Stress can lead to you to feeling 'down' and 'miserable'. What is different about a depressive illness is that these feelings last for weeks or months, rather than days. In addition to feeling low most or all of the time, many other symptoms can occur in depressive illness (though not everybody has every one). These include:
• Being unable to gain pleasure from activities that normally would be pleasurable.
• Losing interest in normal activities, hobbies and everyday life.
• Feeling tired all of the time and having no energy.
• Difficulty sleeping or waking early in the morning (though some feel that they can't get out of bed and 'face the world').
• Having a poor appetite, no interest in food and losing weight (though some people overeat and put on weight - 'comfort eating').
• Losing interest in sex.
• Finding it difficult to concentrate and think straight.
• Feeling restless, tense and anxious.
• Being irritable.
• Losing self-confidence.
• Avoiding other people.
• Finding it harder than usual to make decisions.
• Feeling useless and inadequate - 'a waste of space'.
• Feeling guilty about who you are and what you have done.
• Feeling hopeless - that nothing will make things better.
• Thinking about suicide - this is very common. If you feel this way, talk to somebody about it. If you think somebody else might be thinking this way, ask them about it - IT WILL NOT MAKE THEM MORE LIKELY TO COMMIT SUICIDE.

Diagnostic and statistical manual criteria (DSM)

• Depression