Depression affects how the person feels, behaves and thinks

Depression, also known as major depression, clinical depression or major depressive disorder is a medical illness that causes a constant feeling of sadness and lack of interest. Depression affects how the person feels, behaves and thinks. Depression can lead to emotional and physical problems. Typically, people with depression find it hard to go about their day-to-day activities, and may also feel that life is not worth living.

Feeling sad, or what we may call "depressed", happens to all of us. The sensation usually passes after a while. However, people with a depressive disorder – clinical depression – find that their state interferes with daily life. For people with clinical depression, their normal functioning is undermined to such an extent that both they and those who care about them are affected by it.

Types of depression

There are several forms of depression (depressive disorders). Major depressive disorder and dysthymic disorder are the most common.

Major depressive disorder (major depression)

Major depressive disorder is also known as major depression. The patients suffer from a combination of symptoms that undermine their ability to sleep, study, work, eat, and enjoy activities they used to find pleasurable. Experts say that major depressive disorder can be very disabling, preventing the patient from functioning normally. Some people experience only one episode, while others have recurrences.

Dysthymic disorder (dysthymia)

Dysthymic disorder is also known as dysthymia, or mild chronic depression. The patient will suffer symptoms for a long time, perhaps as long as a couple of years, and often longer. The symptoms are not as severe as in major depression – they do not disable the patient. However, people affected with dysthymic disorder may find it hard to function normally and feel well. Some people experience only one episode during their lifetime, while others may have recurrences.

A person with dysthymia might also experience major depression, once, twice, or more often during their lifetime. Dysthymia can sometimes come with other symptoms. When they do, it is possible that other forms of depression are diagnosed.

Psychotic Depression

When severe depressive illness includes hallucinations, delusions, and/or withdrawing from reality, the patient may be diagnosed with psychotic depression. Psychotic depression is also referred to as delusional depression.

Postpartum depression (postnatal depression)

Postpartum depression is also known as postnatal depression or PND. This is not to be confused with ‘baby blues’ which a mother may feel for a very short period after giving birth.

If a mother develops a major depressive episode within a few weeks of giving birth it is most likely she has developed postpartum depression. Experts believe that about 10% to 15% of all women experience this type of depression after giving birth. Sadly, many of them go undiagnosed and suffer for long periods without treatment and support. Postpartum depression can start any time within a year of giving birth, according to the National Library of Medicine

SAD (seasonal affective disorder)

SAD is much more common the further from the equator you go, where the end of summer means the beginning of less sunlight and more dark hours. A person who develops a depressive illness during the winter months might have SAD.