We're not very good at death, or so we are told. We avoid talking about it, fail to ­accept our ­inevitable end and, in a secular world, seem to have forgotten how to mourn. That hasn't stopped the publishers, however. Grief sells. One publicist advertised a recent addition to their list as appealing to "readers of Joan Didion's The Year of Magical Thinking, Dave Eggers's A Heartbreaking Work of Staggering Genius and Blake Morrison's And When Did You Last See Your Father?".

Didion's memoir, published in 2005 and later turned into a play, charts a year of the writer's life after her husband's sudden death - a year that would end with the death of her daughter Quintana, their only child. (Her next book, Blue Nights, is to be published later this year and will reflect on that second bereavement).

Loss on that scale - the deaths of the only other members of your immediate family - is unimaginable to those who have never experienced it. It is unimaginable even to those who have. You think, when you have been bereaved, that you will understand the bereavement of others better, but you don't. The defining quality of grief, cruel as it seems, is that you pass through it alone. The transformations are comprehensible only to you.
This year alone, a handful of new grief memoirs has been published. Among them are Joyce Carol Oates's A Widow's Story, about the death of her husband; Let Not the Waves of the Sea by Simon Stephenson, about the death of his brother in the 2004 Asian tsunami; and The Long Goodbye by Meghan O'Rourke, about the death of her mother. As you read all these books, persevering through the layers of harrowing, exposing detail, you wonder why writers do it to themselves. Grief tends to leave you speechless, the words straining under the burden, yet the writer is compelled to write.

Reading these books can feel intrusive. O'Rourke's description of shopping for clothes with her dying mother and Stephenson's account of his brother's body arriving back from Thailand make you want to look away, to let these moments remain shielded by familial privacy. Yet it has been the writers' choice to offer up their memories for public consumption - a choice guided by artistic compulsion but also by a simple desire to understand what has happened. Didion once declared in an essay that she writes "to find out what I'm thinking, what I'm looking at, what I see and what it means". O'Rourke, in an email exchange with Oates for the New York Times, echoes the sentiment: "Writing has always been the way I make sense of the world. It's a kind of stay against dread and chaos." Writing, she says, helped her to get "a handle" on grief.

Fair enough, but why publish? O'Rourke has an answer to that, too. She wanted to reflect not only on her suffering, but on "the complexity of loss today". Her memoir is as much a guide to the vast body of mourning literature, from psychological tome to fictional account, as it is a personal account of her mother's death and its aftermath. She reads her way through her grief, taking in everyone from Sigmund Freud to Roland Barthes to Leo Tolstoy.

O'Rourke offers two observations early on: first, a realisation that her grief is entirely personal ("I don't pretend that it is universal"); second, that it is unexceptional - "Nor do I write about it because I think it was more extreme, more unusual, more special than anyone else's. On the contrary: I believe my grief was an everyday one." O'Rourke is wise enough to know that just because she enjoys the privilege of being able to write about her experience, this does not make that experience inherently more meaningful.

Not all memoirists show such restraint. At times, Oates's book feels like a whirlwind of self-indulgence. (Are you allowed to say this about an account of terrible loss?) Unlike O'Rourke and Didion, she didn't wait until the heat of the agony had subsided before committing her thoughts to the page. Instead, the book is, in the most part, her journal, written as she experienced the death of her husband, the editor Ray Smith, after "47 years and 25 days" of marriage. The bulk of the memoir covers the months that follow, and Oates's descent into the deranging horror of grief. Her chapters, all 86 of them, have titles such as "Fury!" and "Please Forgive!" and are punctuated with the exclamation marks, italics and dashes of a writer mid-storm. It is a work of intense vulnerability.

Oates's decision to publish can perhaps be explained by one of her email responses to O'Rourke, in which she admits that writing has always seemed to her like a wholly private act: "I can never quite believe that anything I write, especially in longhand, on scraps of paper . . . will ever be read by anyone else." Given that she has published more than 50 novels, this seems disingenuous at best; but you have to believe Oates when she says that the journal, in the moment of its creation, was not intended for publication. During that initial period of grieving, she felt that the act of writing had become "meaningless, vain and silly". Her scribbled scraps were a survival tactic. (Barthes, coincidentally, wrote his Mourning Diary after the death of his mother on scraps of paper, too. Published for the first time last year, the slim volume revealed the extent of his devotion, as well as a more concise style - many of the entries consist of a single line: "How long everything becomes without her.")

Oates does not present the reader with a tidy version of her grief but instead communicates it wholesale, with all the accompanying illogicality, repetition and confusion. She recounts the kind of madness that overcomes a widow, referring to the "basilisk" that haunts her vision. She is also funny - describing, for instance, a struggle with her cat, which urinates all over her husband's will.

You need the humour. The grief memoir can be an arduous experience for the reader, particularly in its unfiltered, Oatesian form. Fiction deals more gently with the subject, as shown by Julian Barnes's recent short story "Marriage Lines", about a man returning to a Scottish island he had visited with his late wife. In six and a half pages, Barnes manages to reach further into the quiet depths of grief than many memoirists (he published the story not long after his wife, the literary agent Pat Kavanagh, died of a brain tumour). Barnes has never written directly about his wife but he has done a lot of writing about death (his work of non-fiction Nothing To Be Frightened Of was devoted to the subject). He also reviewed Oates's memoir for the New York Review of Books.

In that essay, he took issue with how Oates failed to say at the end of her book that she had remarried. Oates replied in a letter to the magazine, offering a clarifying appendix and observing: "Nothing seems to arouse reproach in reviewers quite so much as the possibility that the memoirist is less miserable at the time of the writing and afterward than she was at the time of the experience about which she is writing." It's a sharp point; but the fault is perhaps less with the reviewer and more with the form. Despite the wealth of literary evidence to the contrary, we naively want memoirs at least to feel like the complete truth. Fiction can rest unchallenged by such expectations.

In either form, grief makes for an uncomfortably intimate subject. Yet such intimacy also offers solace, helping to ease the loneliness that haunts the bereaved. The direct experience of the writer might be unrecognisable, even alienating, to the reader, but their effort alone is a comfort. And when that effort succeeds, as in the Barnes short story or in O'Rourke's clear-eyed reflections, this can be literature at its most purposeful - an act of empathy and generosity, and an embodiment of the idea that reading can make you feel less alone.

Sophie Elmhirst is an assistant editor of the New Statesman