Postpartum psychosis affects approximately one in 1,000 new mothers, but is still rarely discussed; perhaps, as Laura Dockrill suggests in her memoir, What Have I Done?, because of the guilt and shame that attach to women who feel they have failed their babies and themselves by ending up in a psychiatric hospital. So it’s refreshing to see two authors laying bare the nightmare of their own experience, though both memoirs are frequently painful to read.

Catherine Cho’s Inferno is a haunting, eloquent evocation of becoming a stranger to yourself. She writes in spare, allusive prose, weaving in stories from Korean folklore and family history. There is a theme of displacement that runs through the book, from her grandparents, separated permanently from friends and family by the Korean war, through to Cho and her husband, James, Americans living in London when their son is born.

“It’s difficult to know where the story of my psychosis begins,” she writes. “Was it the moment I met my son? Or was it decided in the before, something rooted deeper in my fate, generations ago?”

These questions of fate recur throughout the book, as a specific cultural take on the paranoia and sense of responsibility that plague all women who suffer postpartum psychosis: Did I cause this? Is it somehow my fault? For Cho, there is the guilty knowledge that she deliberately flouted Korean traditions surrounding birth and motherhood, believing herself liberated from such obligations: “I didn’t see why we had to pay attention to Korean traditions – or superstitions, as I thought of them.”

But as her grip on reality loosens, and the illness has her believing she is trapped inside a circle of hell, she turns to family history – her own and her husband’s – for alternative answers. Ghosts, fortune telling, reincarnation and mythology, so much a part of her cultural heritage, now bleed into everyday life, as the doctors and nurses of the psychiatric ward appear to her as demons and angels.

Cho moves between her time in hospital, where she writes in a continuous present as she tries to piece together her memories of who she is, and an account of the events that led her there, from childhood through an early abusive relationship to her marriage and motherhood. Her description of the slide into psychosis is one of the most chilling evocations of madness I have read, all the more terrifying for the calm and measured prose in which she delivers it; it’s hard to believe this is her first book.

Poet and children’s author Dockrill also writes forcefully of the paranoia of psychosis, the conviction that she is the only one who can see “clearly” and the knowledge that no one will believe her (it’s easy to see, in these experiences, the genesis of so many sci-fi and psychological thriller plots). Dockrill’s writing tumbles on to the page in all the messy, raw, breathless chaos of new motherhood; she describes unflinchingly the sense of being reduced to your animal self, with all the stink and leakage and physical pain involved in getting another body out of your own and then sustaining it.

There is no consensus on what causes postpartum psychosis, though a traumatic birth can be a factor. Dockrill’s birth experience is horrific, and because her son is underweight he needs to feed constantly, and eventually her sleep deprivation becomes a persistent feeling of dread. Cultural expectations weigh heavy on her as they do on Cho, not from family tradition this time but from Instagram. “The expectation that I’d fall head over heels in love with my baby was overwhelming. I’d see those photos all over social media, the kind with the smiling-crying happy mum and the naked baby on their chest.” Instead, she is racked by guilt at the lack of bonding. Her son, Jet, “was like the ultimate pet that I couldn’t give back. When would I start to feel anything like love?”

It is the singer Adele – Dockrill’s best friend from their Brit School days – who first suggests she might have postpartum psychosis, as she grows increasingly concerned by Dockrill’s strange and paranoid calls, and Googles “going mad after having a baby”. Dockrill is eventually committed to a psychiatric ward, where she becomes convinced that her musician partner, Hugo, and the doctors are conspiring to steal her baby. What Have I Done? is heartbreaking and brutal in its honesty, and it is remarkable that Dockrill has managed to wring black comedy out of so much suffering.

One of the cruellest aspects of post-partum psychosis is the belief that it is not an illness but a character flaw (“You’re not unwell, you’re just a bitch,” the voice in Dockrill’s head tells her). There is a terrible loneliness to it, and both these books, with their very different tones, offer a hand of solidarity to other women, as well as the assurance that there is a way through. As Dockrill says: “Years ago, would a woman be able to write about this stuff without being called a witch or thrown into an asylum? Probably not, I’m doing it for them too!”

• Inferno by Catherine Cho is published by Bloomsbury (£16.99). To order a copy go to guardianbookshop.com. Free UK p&p over £15

• What Have I Done? by Laura Dockrill is published by Square Peg (£14.99). To order a copy go to guardianbookshop.com. Free UK p&p over £15