Major Depressive Disorder (MDD) is a primary type of Depression. MDD is also called clinical depression.

A patient is said to be suffering from Major Depressive Disorder if he/she has experienced at least one Major Depressive Episode (MDE) in the past two weeks. A Major Depressive Episode takes place if five or more of the following symptoms have been experienced:

• The patient is in a depressed mood all day for the past some days. This can be either reported by the patient of by others who have observed the patient.
• The patient’s interest in level in all activities is diminishing and he/she takes no pleasure in anything. This can also be either reported by the patient of by others who have observed the patient.
• The patient has experienced significant weight loss or weight gain. A decreased appetite or an increase of at least 5% in body weight in a month should be conclusive signs for this.
• The patient is failing to sleep (insomnia) or is sleeping excessively (hypersomnia) almost every day.
• The patient exhibits retardation or psychomotor agitation regularly. This can also be either reported by the patient or reported by others.
• The patient is fatigued or experiences a significant loss of energy.
• The patient is having recurrent thoughts of death and suicide and/or the patient has attempted suicide.

Diagnosis of Major Depressive Disorder

The diagnosis of Major Depressive Disorder is based on the patient’s clinical history. Three things are taken into account in the diagnosis of MDD:

• What the patient has narrated to the physician
• What others have observed about the patient
• What the physician has observed about the patient

If the patient has shown 5 or more of the above-mentioned symptoms, then he/she is diagnosed with Major Depressive Disorder. It is important to note that laboratory tests and related procedures do not play a big role in the diagnosis of Major Depressive Disorder and are seldom availed.