Depression can cause much more than a general feeling of malaise, say researchers. It can lead a person to his first heart attack or to even, a stroke.
What stood out most from this work of the researchers led by Dr. Carmine Pariante of the Institute of Psychiatry at King's College London was the finding that depression was akin to smoking, in that it increased the risks of heart disease by up to five times. And to be noted ,was that this included even depression of a lesser intensity.
Speaking at a conference on depression conducted by the Institute of Psychiatry, Pariante said that hormones and the immune system constituted the main link between depression and heart disease.
In a person subject to depression, they brought about inflammation, which led to atherosclerosis or the narrowing and hardening of arteries by the formation of scaly deposits, reported the researchers.
Cautioned Pariante: "The longer you've been depressed and the more episodes you have and more severe they are, the worse are the biological impacts."
Another such disastrous effect of depression is the birth of preterm infants, which is known to compromise their health and sometimes-even their existence.
Led by Veronica O'Keane of the Institute of Psychiatry at King's College London, researchers conducted the first clinical study into depression found in pregnant women.
According to them, depression in pregnant women, or antenatal depression is a 'largely hidden problem'.
O'Keane studied two groups of women, one severely depressed and the other healthy, and followed them throughout their period of pregnancy.
Levels of stress hormones were measured using blood and saliva tests and their moods were assessed using psychiatric tests.
It was seen that there were significantly higher levels of the stress hormone Corticotropin -releasing hormone (CRH) in the depressed women.
It was also seen that significantly, the length of pregnancy in average, was much shorter in depressed women. This the researchers attributed to the overproduction of stress hormones.
According to O'Keane: "There's a myth really that women are protected from depression during pregnancy and that they are happy during pregnancy. But this actually isn't true if you look at it scientifically."
O'Keane says this medical myth might have arisen because most women do not go to the doctor with depressive symptoms until after they have had the baby. At that point, the stress of trying to care for the infant at the same time often becomes overwhelming.
The NHS says that around one in 10 women in the UK suffer from post-natal depression.
Higher levels of hormones are actually necessary for the normal development of the baby, but the levels of these hormones are also raised in expecting women with depression.
If the stress hormone levels are too high though - for example if the mother is depressed during the pregnancy - this can lead to premature birth, the leading cause of infant death and postnatal illness in the world, warns O'Keane.
Not only that, there is also evidence that women with the highest stress hormone levels are more prone to having children with abnormal stress responses themselves. "This is an inter-generational way of transmitting depression without it being genetic," says the doctor.
So, wherein lies the solution ?
O'Keane believes that more doctors should be aware of depression during pregnancies and that women on anti-depressants should not automatically stop taking them when they conceive.
"I don't think women with a history of depression should discontinue their medication. I think they should go to a perinatal specialist who can recommend the best treatment during the pregnancy", she opines.