DEPRESSION

  
 

It is common to be unhappy when disappointed, and most people get depressed over job layoffs, divorce, the death of a loved one or other major losses. Sadness is a normal part of life, but when it is unrelenting, it may be indicative of a major  mental-health problem, "clinical depression." Depression is a real illness, just like heart disease or diabetes, and not merely a state of mind that people can "snap out of" if they are willing. Just as people deal with any chronic disease, they must learn how to recognise depression and control it throughout their lives.

 
  WHAT IS DEPRESSION?  
  Depression is an illness that causes a disturbance in an individual's emotions and feelings, what is referred to as mood. Most people experience a down mood from time to time throughout their lives. True depression is suspected when people consistently find themselves in depressed moods every day over a period of two weeks or more. Typically, if people are suffering from depression, their mood will prevent them from living their lives as they normally do. Stressful life events, like a death in the family or financial problems, can trigger depression. Sometimes, people find themselves depressed for no apparent reason.  
  Most often, depression produces a sad mood. However, some people experience indifference, apathy, loss of pleasure or irritability instead. In addition to mood disturbance, depression can interfere with several basic body functions including changes in sleep, decreased or increased appetite, sluggishness, restlessness, fatigue, loss of concentration and poor memory. People with depression may feel excessive shame or guilt and dwell on thoughts of death or dying, including ideas about suicide.  
  WHO GET'S THIS DISEASE?  
  About 5 percent of the population suffers from depression. It affects people of all ages, races and ethnic groups. For unknown reasons, women are almost twice as likely as men to suffer from depression; the lifetime prevalence of major depression is about 20 to 26 percent for women and 8 to 12 percent for men.  
  Unlike other diseases that an individual can contract only once in a lifetime, depression is a recurrent condition. Those who have had an episode of depression have a more than 50 percent chance of the depression recurring sometime in their lives. Depression can occur at any age, but the average age of onset is about 40. Although many people experience their first episode of depression in their late teens or early adulthood, the incidence of depression increases with age. The elderly are at a high risk of developing depression as they face multiple health problems or the loss of loved ones. Persons of any age or race may contemplate suicide as part of their depression, but older white men are more likely than younger individuals to actually commit suicide.  
  WHAT CAUSES DEPRESSION?  
  The underlying causes of depression are not well understood, although there are many clues suggesting that various systems in the brain may cause depression or be affected by it. The brain is the control centre for every part of the body – it controls our conscious behaviour (walking and thinking) and our involuntary behaviour (heartbeat and breathing). The brain also regulates our emotions, memory, self-awareness and thought processes.  
 

The most probable explanation, and the one on which treatment with anti-depressant drugs is based, is that depression is due to an imbalance in certain chemical messengers (neurotransmitters) in the brain. The neurotransmitters transfer messages between nerve cells in the brain. Some evidence suggests that depression is caused by a deficiency in two neurotransmitters called noradrenaline and serotonin. Abnormalities in the neuroendocrine system of the brain also seem to play a role in depression, including abnormalities linked to the thyroid, pituitary and adrenal glands.

 
 

But if depression is caused by an imbalance in these neurotransmitters, what triggers it in the first place?

 
 

Genetic Factors: Some people certainly seem to be more vulnerable to depression than others and there is growing evidence that some genes could make individuals susceptible to the disease. This would also explain why depression often runs in families. Somestudies have shown that people who have relatives with depression have a one in four chance of developing it themselves, compared with only one in 14 for the general population.

 
  There is mounting evidence to suggest that several genes may be responsible for causing depression.  
 

External Triggers: Social and Environmental Factors - However, in most cases just having these genes is probably not enough to cause depression on its own. Stressful situations can exacerbate this vulnerability. Depression can be triggered by a number of factors such as unemployment, bereavement, divorce, social isolation or even a severe physical illness.

 
 

Strokes and Depression: In some cases, a stroke may cause depression. One study of older adults found that damage to specific areas of the brain were more likely to be found in people with major depression than in healthy individuals, or patients with dementia (progressive decline in the ability to think and reason). These small, subcortical strokes are the type found in individuals with long-standing high blood pressure (hypertension), diabetes or other medical illnesses that affect blood vessels in the brain, heart and other organs.