Defining depression is not an easy task. Depression can be described as a mental state in which a person can suffer from melancholy, despair, and intense sadness.

Clinical depression or MDD (major depressive disorder) is a condition in which a person’s day to day functioning and social life is disrupted because of depression. It is normal for people to feel depressed sometimes, however a continuous state of depression poses a serious health concern.

Statistically speaking, 7-18% of the population experiences clinical depression at least once before the age of 40. The WHO (World Health Organization) has calculated that clinical depression will soon become the second leading cause of disability in the world.

Unlike other clinical illnesses, there is no spot test available to instantly diagnose clinical depression. Clinical depression is diagnosed primarily based on symptoms. What has made diagnosing clinical depression difficult is that there is no single symptom that can point to clinical depression.

Common symptoms of clinical depression include displeasure, excessive sleeping, weight loss and a general lack of happiness. Clinical depression is divided into various categories based on the symptoms a patient exhibits.

One of the most common forms of clinical depression is (ironically) called atypical depression.

In rare cases, a person suffering from depression can experience extreme mood swings, these mood swings can fluctuate between extreme depression and euphoria; this type of depression was earlier termed as manic depression.

Manic depression is now known as bipolar disorder. Bipolar disorder is simpler to diagnose when compared to other forms of depression.

As mentioned earlier in the article, diagnosing depression is not an easy task. It requires considerable experience to differentiate between the various forms of depression. Diagnosis is carried out using a questionnaire based system.

A patient’s responses are analysed by a psychiatrist to determine if a patient is in fact, suffering from depression. Blood tests are also carried out to check for hormonal imbalance, but blood tests are usually carried out after a person is diagnosed with clinical depression.

There are numerous scientific theories that attribute depression to both physiological and socio-psychological reasons.

The physiological causes for depression include electrolyte imbalances, genetic factors and hormonal imbalances (usually seen in women immediately after child birth or during PMS). Additional reasons for depression include lack of sleep, and Seasonal affective disorder (SAD).

Socio-psychological reasons for depression include traumatic childhood experiences, poverty and low self esteem. As of today, no single theory can conclusively point to the cause of depression. It was previously believed that excessive alcohol consumption was a result of depression.

Studies have shown that excessive alcohol consumption can also lead to depression. Similarly, excessive eating and substance abuse can also lead to depression.

Since there is no single form of depression, treatment of depression varies broadly among individuals. Factors like the level and severity of symptoms influence a psychiatrist’s treatment criteria.

Drugs are only effective in certain kinds of depression and not all types of depression can be treated using a fixed formula or by using drugs alone.