A 26 year old lady had developed headache, palpitations, bodyache, weakness, sleep disturbance, reduced appetite, frequent crying and was intolerant to noise, not interested in doing house-hold work and even not interested in looking after her recently born baby-boy. She would sit alone, not mix with family members and other relatives. She thought that she was not capable of looking after the baby-boy and used to tell her mother-in-law that she would have to bring him up. The patient had lost all confidence in herself. She was feeling that it would be better if she dies as she was troubling others (guilt feelings) and if she were dead everybody would be relieved.

The patient had delivered a baby-boy, normal delivery. Within one month of delivery, she had developed above symptoms.

There was no psychological stress in the family. Her husband and in-laws, were good and good inter-personal relationship existed them. The family was financially well-off.

Everyone was trying to explain to her that "Do not worry everything would be all right." On the advice of others, the couple had gone out on a vacation for about two weeks, In spite of all these the above symptoms persisted.

This is a case of Depressive Disease (Post Partum Depression). The patient’s mother had suffered from Depressive disease. This is a typical case where biological factors were predominant in the causation of the depressive disease.

With the proper antidepressant treatment, patient improved fully within four weeks.

Chemical Theory

The transmission of the nerve impulse (message) is both electrical and chemical. There is a gap (very minute, observed through only electron microscope) between the two cells. This gap is known as "Synapse" The transmission of the nerve impulse through synapse is by chemicals. Some of the chemicals that transmit the nerve impulse (messages) are dopamine, norepinephrine, epinephrine, serotonin (5 HT) gamma aminobutryric acid (GABA), and acetylcholine.

The changes in the quality and quantity of these chemicals at the synapse will affect the transmission of messages, thus affecting processes like movement, thinking, feeling, behavior etc. It has been proved beyond doubt that in Parkinson’s Disease (a neurological disease) dopamine levels are reduced in certain areas of the brain, thus resulting in tremors, slowness of body movement, and rigidity. As a treatment, this chemical is given as a medication.

In Depressive Disease there are changes in dopamine and serotonin level at the synapse in the brain. The drugs, which modify these levels, improve the disease.

| Genetic | Bio-chemical | Psychological | Social factors |