Of all the things depression has prevented me from doing over the years, having children is perhaps the most poignant. But since you can’t really miss something you never had, it’s no biggy.
I mention it now because these last few months of getting myÂ depression more or less under control has made me wonder what my life could have been if I’d got my act together sooner. And of course it’s Mother’s Day tomorrow, which, for all us childless women, rubs it in every year.
The decision not to have children happened when I was a schoolgirl, 14 or 15 years old, and desperate at feeling so miserable all the time. I could not risk passing this anguish on to my own children, as I perceived my mother had to me (since nothing other than genetics could have caused it, I reasoned). I made my future self promise not to have children, by writing a little song that I reckonedÂ would stick with me through any changes of heart later.
Was it the right decision? Risk-wise, yes. Â My children would have been 4 or 5 times more likely than the average person to suffer from depression. Terrible odds. If I had packed up drinking and tackled my depression 20 years ago, would I have broken the promise to my 14 year old self? Probably. But as they say a lot in AA: woulda, coulda, shoulda. Best not to dwell on it.
The lack of public discourseÂ about this surprises me, although it probably shouldn’t, given the stigma still attached to mental illness. Â Having just seen Still Alice, a film about a linguistics professor (played by Julianne Moore, below) who is diagnosed with early onset Alzheimer’s aged 50, the choices people make concerning their genetic inheritance seem familiar. Â (Take a bow,Â Angelina Jolie.)
The following is taken from Stanford University School of Medicine’s Major Depression and Genetics page:
How do we know that genes play a role in causing depression? Scientists look at patterns of illness in families to estimate their â€œheritability,â€ or roughly what percentage of their cause is due to genes. To do this we find people with the disease who have a twin, and then find out whether the twin is also ill. Identical (monozygotic) twins share 100% of their genes, while non-identical (â€œfraternalâ€ or dizygotic) twins share 50% of their genes. If genes are part of the cause, we expect a patientâ€™s identical twin to have a much higher risk of disease than a patientâ€™s non-identical twin. That is the case for major depression. Heritability is probably 40-50%, and might be higher for severe depression.
This could mean that in most cases of depression, around 50% of the cause is genetic, and around 50% is unrelated to genes (psychological or physical factors). Or it could mean that in some cases, the tendency to become depressed is almost completely genetic, and in other cases it is not really genetic at all. We donâ€™t know the answer yet.
We can also look at adoption studies, to see whether an adopted personâ€™s risk of depression is greater if a biological parent had depression. This also seems to be the case.
What about non-genetic factors? There are probably many non-genetic factors that increase risk of depression, many of which are probably not yet known. Severe childhood physical or sexual abuse, childhood emotional and physical neglect, and severe life stress are probably all risk factors. Losing a parent early in life probably also increases risk to some extent.
If someone has a family history of depression, are they at very high risk? If someone has a parent or sibling with major depression, that person probably has a 2 or 3 times greater risk of developing depression compared with the average person (or around 20-30% instead of 10%).
The situation is a little different if the parent or sibling has had depression more than once (â€œrecurrent depressionâ€), and if the depression started relatively early in life (childhood, teens or twenties). This form of depression is less common â€“ the exact percentage of the population is not known, but is probably around 3-5%. But the siblings and children of people with this form of depression probably develop it at a rate that is 4 or 5 times greater than the average person.