Major depressive disorder (unipolar disorder)
Also known as major depression. Characterised by a low emotional state, sadness, lack of energy and self-worth and often, feelings of guilt. The patient suffers from a combination of symptoms that undermine their ability to sleep, eat, study, work e.t.c.
Experts say that MDD can be very disabling, preventing the patient from functioning normally.
Some people experience only one episode whilst others have recurrences.
Also known as dysthymia or mild chronic depression.The patient will suffer symptoms for a long time, perhaps even a couple of years.
The symptoms are not as severe as in MDD and the patient is not diasabled by it. However, they may find it hard to function still.
Some people experience only one episode whilst other experience recurrences.
A person with dysthymia may also experience MDD multiple times in their life. When they do, it is possible they may also be diagnosed with other depressive disorders.
Other forms of depression
Psychotic depression When severe depressive illness includes hallucinations, delusions and/or withdrawing from reality, the patient may be diagnosed with psychotic depression.
Postpartum depression Also known as postnatal depression (PND.) 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 then it is most likely she has developed PND.
It is believed that about 10-15% of new mothers experince PND.
Seasonal Affective Disorder (SAD) is much more common the further from the equator you go. A person who develops a depressive illness during the winter months but recover during the Spring/Summer might have SAD.
Sufferers often go through 'light therapy' in which they are exposed to a special light which, for around 50% of sufferers is able to relieve the symptoms of SAD.
Patients may also require antidepressants and/or psychotherapy.