On Boxing Day, when my first child was four months old, I woke up in A&E, unsure how I’d got there. I had stiches in the back of my head, a cannula in my hand, a blinding headache and rock-hard, leaking breasts. Gradually I was able to piece events together. An incident involving huge quantities of raspberry vodka, a staircase and the hard metal edge of a radiator right at the bottom.

My son’s first Christmas should have been special and, by and large, it was. However, having spent the past year either pregnant or breastfeeding, I’d decided to treat myself to some alcohol. I’d expressed plenty of milk in advance, so what could possibly go wrong? Falling backwards downstairs blind drunk, that’s what.

Still, at least it wasn’t a fatal fall, although I do wonder about the narrative that would have followed such a thing: “she seemed so happy with motherhood but was in fact hiding a dark secret: an addiction to booze!”, or “”having finally found peace through family life, what could have led her to self-destruct?” That one can be a mother, a mother who loves her children very much, yet still do selfish, self-destructive things is hard for people to accept. It is inconvenient. Mothers should not be weak – they exist to absorb the weaknesses of others – so human frailty cannot be part of the motherhood story.

The incident with the vodka and the staircase is one of not many, but enough. I’ve suffered from depression and eating disorders for most of my life. I do not accept these things as “just how I am” – I’ve sought various treatments over the years and I am stable – but the mere existence of my children has not miraculously saved me from being the flawed person I was before they arrived. I realise how painful such confessions must be to people who want children but do not have them. I believe them when they say they would be better than me, that they would not make mistakes in the way I have. Nevertheless, I would argue that most of the time I am the mother I am supposed to be. Moments of dark self-absorption are rare but then it only takes one to shatter the whole motherhood myth.

Right now the “secret double life” of Peaches Geldof is the subject of much tabloid speculation. How could a young mother who claimed to be so utterly transformed by parenthood – who vaunted the benefits of attachment parenting and was seen by others as a “parenting role model” – have been a heroin addict all along? How could she have strung everyone along, including those closest to her? There is, it is implied, a real disjuncture between the image of idyllic motherhood she projected and the life she was actually leading. It is as though the two cannot coexist; either you are a real mummy or you are not. If you have felt the bliss that is holding your child close to you, breathing in his or her scent, surely you could never fall back on the sheer self-indulgence that is addiction? I think you can. The love a mother feels for her children doesn’t override every other emotion all the time; it’s just that we would like it to.

In July’s edition of Glamour a male journalist expresses his envy of the way in which pregnancy and birth appear to make sorted, selfless human beings of women:

Mid-life crisis? Women have no time for that shit. From the outside, pregnancy looks like a nine-month crash course in the meaning of life. We men, on the other hand, seem destined to spend our late forties seeking enlightenment in Lycra that doesn’t fit, on carbon fibre bikes we can’t afford, doing triathlons. Yes, childbirth might do us a favour."

Except this doesn’t actually happen. We do not gain access to the meaning of life. Our babies are new, innocent, as yet untainted by foolish obsessions; we, on the other hand, still keep the scars we had before.

I cannot imagine shooting up heroin while alone in the house with a one-year-old son. But then there will be people who cannot imagine taking SSRIs while pregnant and breastfeeding, or being so desperate to make yourself vomit that you accidentally swallow a toothbrush and are too busy being X-rayed to pick your children up from nursery. I can imagine that, easily. Such things are not part of anyone’s dream of motherhood but mothers do them all the same, not because they want to, but because they are struggling and mess up, just as all human beings do. In Tennessee, Mallory Loyola has become the first woman to be prosecuted for assault “for the illegal use of a narcotic while pregnant”. It is reported that Loyola had a history of drug abuse. That she carried on being the same person while pregnant is apparently a criminal offence. How can we be so unforgiving?

People who did not live her life do not have the right to judge Geldof. Hiding drugs in a loft, lying to your partner, dying at 25 hunched over a tied-up pair of tights – no one wants that to be how they are remembered. No one does this for the sheer hell of it. No one does it because they simply don’t love their children enough and haven’t let the sheer magic of parenthood transform their lives. So Geldof pretended that the joy she felt with her sons was all that she could possibly experience. Why not? Everyone wanted that to be the case and for a while, everyone loved her for it. It is how one “does” motherhood in the public eye, and even in private. I too know the transient joys of pottering about in domestic goddess mode, pretending that the innocence and purity of one’s offspring enables one to start life anew. Sadly, this doesn’t happen and besides, it’s not what children are there for. They are people in their own right, not living, breathing substitutes for a stay at The Priory.

Recognising the humanity of those who raise our young might not always be enough to save them, but it might allow those they leave behind to know that they were loved all the same.