She was old and ill, and the illness was debilitating and dehumanising. Her death was a blessing. But to her. Only to her.

A few months after the death, a doctor asked one of the daughters how they were managing.

Of course they not managing. This was not a manageable situation. Did he believe that this got better for anyone?

The doctor's response was a snort of disbelief. Doctors should snort more; it's very funny. At the time, the bereaved daughter thought to throw a chair at him, but agrees it's definitely funny now.

A year after her mother died she cried for the first time and stayed in bed for ten months. Later, one of her friends told her that when the mother died, it seemed like the rest of the family did too. She'd gone and taken them with her.

Prolonged Grief Disorder (PGD) - sometimes still referred to as Complicated Grief - is painfully prevalent. I didn't know this was a thing worth pursuing until I saw, at the very end of an article, the word 'unrecognised.'

The Center for Complicated Grief at the Columbia School of Social Work suggests as many as 20 per cent of patients getting some kind of mental health help have unrecognised PGD.

How masked are these symptoms that you can fail to recognise it in so many people?

Suspecting that I and everyone in my family suffered or suffers from PGD, I'd like to go pick out my exceedingly high horse, tie a soapbox to it (but I don't know if they still make them), and then get on top of that.

From there, I will shout and rant and wail about how obvious this condition should be in presentation.

What it pleases the world to call 'normal grief' looks a lot like PGD, but lasts maybe a month or so before the pieces of life and routine start to fall into place. They go back to work, they go out, they get back to their tennis lessons.

In short, their life resumes. Doubtless they remember the deceased and think on them, but they are not manacled to their grief.

And this is where the PGD sufferers start to look very different.

They do not move on. Rather, they cling to every sensory surface that reminds them of the lost one. They live inside their loss - in the scent of the person's room, in photographs and songs, they daydream about them being alive still.

We can see from this small sketch how many beloved - or feared - fictional characters may have had PGD: Heathcliff and his tormented grave vigil (we will not speak of the near-necromancy, I'm not qualified); Miss Havisham and her stopped-clock house; the skeletal Ralph Fiennes as Almásy telling his never-ending tale of love, death and treachery in The English Patient.

Not to be judgemental, but all those people seemed completely out of their minds.

Perhaps this is the problem with diagnosis?

This extreme display of grief looks not so much like something you can deal with in a neat multi-step programme, but with a straitjacket and a padded cell.

Why is it not depression? Delusion - some people just refuse to believe the person is dead? One peer-reviewed pie