Clinical depression (also called major depressive disorder, or unipolar depression when compared to bipolar disorder) is a state of intense sadness, melancholia or despair that has advanced to the point of being disruptive to an individual's social functioning and/or activities of daily living. Depression affects people differently. Some feel down for extended periods of time; for others the feelings of depression come and go. Depression is a mood disorder that causes you to feel sad or hopeless for an extended period of time. More than just a bout of "the blues" or temporary feelings of grief or low energy. Many people identify the feeling of being clinically depressed as "feeling sad for no reason", or "having no motivation to do anything." One suffering from depression may feel tired, sad, irritable, lazy, unmotivated, and apathetic.

Clinical depression is not just grief or sadness. Clinical depression is generally acknowledged to be more serious than normal depressed feelings. It often leads to constant negative thinking and sometimes substance abuse. Extreme depression can culminate in its sufferers attempting or committing suicide. There are three main types of depression; unipolar disorder (major depression), bipolar disorder (manic depression) and dysthymia (prolonged sadness). Major depression usually strikes people between the ages of 25 and 44, although it can affect any person at any age. For most people, episodes of major depression last from six to nine months. Feelings of total indestructibility are common, and the manic person may believe for example that not even moving cars can stop him or her, or that he or she can fly. They experience delusions and hallucinations and sometimes talk so fast that their speech becomes illegible.

Causes of Clinical Depression

1. Genetic Predisposition (Hormonal imbalance ).

2. Medical conditions (Neurochemical ).

3. Dietary .

4. Alcohol and other drugs.

5. Sleep quality.

6. Certain styles of thinking.

Symptoms of Clinical Depression

1. Persistent feelings of sadness, irritability, or anxiety

2. Overreaction to irritations

3. Loss of interest in activities previously enjoyed, including sex

4. Sleeping too much, sleeping too little

5. Losing or gaining weight.

Treatment of Clinical Depression

Medication that relieves the symptoms of depression has been available for several decades such as citalopram (Celexa), fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft). Under some circumstances, medication and psychotherapy may be more effective than either treatment separately. Family of drugs includes fluoxetine (Prozac), paroxetine (Paxil), escitalopram (Lexapro), citalopram (Celexa), and sertraline (Zoloft). These antidepressants typically have fewer adverse side effects than the tricyclics or the MAOIs, although such effects as drowsiness, dry mouth, nervousness, anxiety, insomnia, decreased appetite, and decreased ability to function sexually may occur. Serotonin-norepinephrine reuptake inhibitors (SNRIs) such as venlafaxine (Effexor) and duloxetine (Cymbalta) are a newer form of antidepressant that works on both norepinephrine and 5-HT.Selective serotonin reuptake inhibitors (SSRIs) are medications that increase the amount of the neurochemical serotonin in the brain.

Norepinephrine (noradrenaline) reuptake inhibitors (NRIs) such as reboxetine (Edronax) act via norepinephrine (also known as noradrenaline). Tricyclic antidepressants are the oldest and include such medications as amitriptyline and desipramine. Tricyclics block the reuptake of certain neurotransmitters such as norepinephrine (noradrenaline) and serotonin. They are used less commonly now due to the development of more selective and safer drugs. Monoamine oxidase inhibitors (MAOIs) such as phenelzine (Nardil) may be used if other antidepressant medications are ineffective. Because there are potentially fatal interactions between this class of medication and certain foods, particularly those containing Tyramine. electroconvulsive therapy, are used in severe cases.