What is it?
Postnatal depression (PND) affects 10-15 per cent of women after childbirth, and is like other forms of depression, including anxiety and mood swings, tearfulness, low self-confidence, feelings of guilt and worthlessness, an inability to concentrate, and loss of appetite and insomnia. In its more severe forms, it may also be accompanied by thoughts of suicide. Appearing during the first four weeks after delivery, the symptoms can last months or even years.

PND is different from the ‘baby blues’ - a transient condition that affects most mothers within the first two weeks after birth, yet with similar symptoms to PND. Postpuerperal psychosis is a much rarer condition - affecting 0.1-0.2 per cent of mothers - accompanied by hallucinations, delusions and disorganised or catatonic behaviour.

PND can have a major negative impact on the relationship between mother and baby, with implications for cognitive and emotional development, and links to anxiety and low self-esteem in the child as well as in other family members.

What causes it?
The rapid drop in reproductive hormones in the aftermath of delivery is thought to be one of the main causes of depression, though other factors may be involved. Childbirth and the first month after delivery are both physically and mentally exhausting. You may be deprived of sleep and deficient in the nutrients that have been passed to the baby during pregnancy (and will continue to be while you are breastfeeding). You also have to adjust psychologically to a new lifestyle. Stressful life events and relationships may also contribute.

Women who have had past episodes of depression (unrelated to childbirth) are more prone to postnatal depression.

What doctors tell you
Despite the available alternative treatments, especially as mothers are often unwilling to take drugs, your GP’s first port of call for PND is usually antidepressants.

Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac), sertraline and venlafaxine can relieve PND - but at a price. Side-effects include nausea, anorexia, diarrhoea, anxiety, nervousness, insomnia (the last thing a new mother needs) and drowsiness.

These drugs can also be transferred to the baby via breastmilk. Although studies have found only very low levels in infants’ blood, it may not be the case in the brain. When present in the blood, fluoxetine has led to an increase in crying, diarrhoea, vomiting, colic, poor sleep and weight loss (Br J Clin Pharmacol, 1999; 48: 521-7). And with no long-term studies of infants exposed to SSRIs via breastmilk, no one knows what SSRI levels in blood are ‘safe’ (Am J Psychiatry, 1996; 153: 1132-7).

When all else fails, doctors usually reach for hormones. Synthetic oestrogen can relieve the symptoms of PND within two weeks, but this may cause a decreased milk production and an increased risk of thromboembolism. Progesterone can make depression worse (Br J Obstet Gynaecol, 1998; 105: 1082-90).

Michelle Clare