It's difficult to give a definite answer because every woman is different, but as a general rule it takes a matter of weeks for antidepressants to have an effect. You may see some improvement within a week or so, but it still takes up to six weeks for the maximum benefit to develop. For a few women, improvements are a lot slower in coming. Some don't respond to the initial treatment at all, and it's necessary to try other drugs or therapies.
Many factors to take into account
One of the problems with postnatal depression is that we still don't fully understand the cause, and so many different factors need to be taken into account. Treatment, including antidepressants, can be a bit of a random approach to cover the symptoms while the real trigger is unknown.
There may be physical causes which may improve or be responsive to treatment, such as a hormonal change, but there are also many other contributing factors which drug treatment can't change.
For example, most parents find a new baby exhausting work and many mothers in particular suffer immense disruption to their sleep. This tiredness can add to depression, and needs as much practical support and help from family and friends as possible. A bit of rest or the eventual settling of the baby into a regular routine (including sleeping through the night) may be almost as effective as a course of antidepressants.
Loneliness, anxieties about being responsible for such a tiny life, and worries about the baby can all add to a low mood. Women who had a successful career before the baby can find the change in role very hard to adapt to, although postnatal depression is just as likely to hit women whose main goal has always been to have their own family.
Support and patience
Antidepressants alone aren't a miracle cure for postnatal depression. Even if your partner starts to get better she may need time and help to settle into life with a small child.
What your partner needs now is plenty of practical and emotional support. Show her that you understand her feelings and try to be patient for her recovery. Encourage her to make contact with other new mothers and talk to her health visitor, and help her to find reliable babysitters so you can both continue to make time to be together and talk together, as your old 'pre-baby' selves.
This article was last medically reviewed by Dr Trisha Macnair in June 2008
