What is depression?
Depression can be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for short periods. But true clinical depression is a mood disorder in which feelings of sadness, loss, anger, or frustration interfere with everyday life for an extended time. Depression can be mild, moderate, or severe. The degree of depression, which your doctor can determine, influences how you are treated.

Postnatal depression affects 1 in 10 women.

How common is depression during and after pregnancy?
Depression that occurs during pregnancy or within a year after delivery is called perinatal depression. The exact number of women with depression during this time is unknown. But researchers believe that depression is one of the most common complications during and after pregnancy.

Often, the depression is not recognized or treated, because some normal pregnancy changes cause similar symptoms and are happening at the same time. Tiredness, problems sleeping, stronger emotional reactions, and changes in body weight may occur during pregnancy and after pregnancy. But these symptoms may also be signs of depression.

What causes depression?
There may be a number of reasons why a woman gets depressed. Hormone changes or a stressful life event, such as a death in the family, can cause chemical changes in the brain that lead to depression. Depression is also an illness that runs in some families. Other times, it's not clear what causes depression.

During Pregnancy
During pregnancy, these factors may increase a woman's chance of depression:

• History of depression or substance abuse
• Family history of mental illness
• Little support from family and friends
• Anxiety about the foetus
• Problems with previous pregnancy or birth
• Marital or financial problems
• Young age (of mother)

After Pregnancy
Depression after pregnancy is called postpartum depression or peripartum depression. After pregnancy, hormonal changes in a woman's body may trigger symptoms of depression. During pregnancy, the amount of two female hormones, estrogen and progesterone, in a woman's body increases greatly. In the first 24 hours after childbirth, the amount of these hormones rapidly drops back down to their normal non-pregnant levels. Researchers think the fast change in hormone levels may lead to depression, just as smaller changes in hormones can affect a woman's moods before she gets her menstrual period.

Occasionally, levels of thyroid hormones may also drop after giving birth. The thyroid is a small gland in the neck that helps to regulate your metabolism (how your body uses and stores energy from food). Low thyroid levels can cause symptoms of depression including depressed mood, decreased interest in things, irritability, fatigue, difficulty concentrating, sleep problems, and weight gain. A simple blood test can tell if this condition is causing a woman's depression. If so, thyroid medicine can be prescribed by a doctor.

Other factors that may contribute to postpartum depression include:

• Feeling tired after delivery, broken sleep patterns, and not enough rest often keeps a new mother from regaining her full strength for weeks
   
• Feeling overwhelmed with a new, or another, baby to take care of and doubting your ability to be a good mother.
   
• Feeling stress from changes in work and home routines. Sometimes, women think they have to be "super mom" or perfect, which is not realistic and can add stress.
   
• Having feelings of loss - loss of identity of who you are, or were, before having the baby, loss of control, loss of your pre-pregnancy figure, and feeling less attractive.
   
• Having less free time and less control over time. Having to stay home indoors for longer periods of time and having less time to spend with the your partner and loved ones.

How is depression treated?
There are two common types of treatment for depression.

• Talk therapy. This involves talking to a therapist, psychologist, or social worker to learn to change how depression makes you think, feel, and act.
   

• Medicine. Your doctor can give you an antidepressant medicine to help you. These medicines can help relieve the symptoms of depression.

Women who are pregnant or breastfeeding should talk with their doctors about the advantages and risks of taking antidepressant medicines. Some women are concerned that taking these medicines may harm the baby. A mother's depression can affect her baby's development, so getting treatment is important for both mother and baby. The risks of taking medicine have to be weighed against the risks of depression. It is a decision that women need to discuss carefully with their doctors. Women who decide to take antidepressant medicines should talk to their doctors about which antidepressant medicines are safer to take while pregnant or breastfeeding.