Depression

Introduction

 Mood disorders
 Unipolar vs bipolar mood disorders

Depression is a mood disorder that causes a disturbance in an individual's emotions and feelings; if someone has depression, or a depressive illness, they experience a pervasive and sustained change in mood which leaves them feeling persistently sad, worthless and helpless. These feelings may be triggered by a life event, such as the death of a loved one, or they can occur for no identifiable reason. Without treatment, symptoms can last for weeks or even years, rendering life meaningless and hopeless for the sufferer.

Mood Disorders

These are sometimes also referred to as affective disorders. They include episodes of depression, where mood is abnormally low, and of mania, where mood is abnormally high. These disorders are broadly divided into unipolar disorders and bipolar disorders. Nearly all patients who have mania eventually experience at least one period of depression as well. Individual episodes in mood disorders vary in length but last many months if left untreated. Some patients have recurrent episodes throughout their lives.

Find out about serotonin and mood disorders

Unipolar vs Bipolar Mood Disorders

This distinguishes the two main types of mood disorder, on the basis of the presence or absence of manic as well as depressive episodes:

• unipolar mood disorder, in which patients experience depressive episodes only

• bipolar mood disorder (manic depression), where patients experience both depressive and manic episodes.

Unipolar depression occurs from adolescence, with prevalence peaking between 40-50 years, and a gradual decline after the age of 60 years.

Bipolar disorder commonly presents earlier than depression, with most patients suffering their first manic or hypomanic episodes by their early 20s.

Unipolar Disorders

We would not be human if we did not know what it feels like to be sad, lonely or unhappy at times. Usually, we have an obvious reason for our feelings, such as grief or disappointment following some traumatic life event. We recover from them at varying speeds, but generally within a few weeks. Clinical depression is the situation that arises when the depth or duration of these feelings becomes so great that they are no longer 'understandable', but seem irrational and out of proportion to the circumstances. In such cases, feelings of sadness and tears may not be the most obvious features, but other psychological and physical symptoms appear. The diagnosis of clinical depression is made on the basis of these distinguishing features. It is estimated that 17% of the population will suffer with depression at some stage of their lives (Kaplan et al., 1994).

Bipolar Disorders

These disorders are characterised by symptoms of feeling down (depressed) and high (manic), usually in a fluctuating course. Based on the severity of the mania symptoms the bipolar disorder is classified by DSM-IV as bipolar I for severe mania, and bipolar II for milder manic episodes, or hypomania. Occasionally mania- and hypomania episodes can occur as a result of antidepressant treatment; so-called induced mania/hypomania (bipolar III). The characteristics of a manic episode are:

• inflated self-esteem or grandiosity

• frantic work activity and increased talkativeness

• decreased need for sleep

• flights of ideas or racing thoughts, poor concentration. impulsive behaviour to the point of danger or recklessness.

Characteristics of Depressive vs Manic Episodes