The first thing Sabah Kaiser does after sitting down at the table when we meet, is to pick up a pen, and write her name on the nearest sheet of paper. She does it almost unthinkingly, and only later will it come to seem significant.

When she was a little girl, Kaiser wrote her name a lot. She scrawled it defiantly on the wall at home, balancing precariously on a banister four floors above the ground to reach the wallpaper: “Sabah is the best.” Later, she wrote it in foster homes: “I would find the hardest place that I could reach, or the most beautiful or lovely area, and write ‘Sabah is the best’.”

It was a coping mechanism she learned young, without really understanding why. But now, at 43, she recognises it as a way of fighting the feelings of worthlessness and shame so many child abuse survivors experience. “It was saying: ‘Look at me, I belong here; I can do the same as you, if not better.’”

The name she writes now is not, however, the same one she had then. Kaiser changed it by deed poll years ago, borrowing inspiration from Keyser Söze, the character in the film The Usual Suspects who has a double life. Kaiser, she explains, means king; above other men, but below God. It is a powerful name, and the one under which she approached the Truth Project.

Set up by the government’s Independent Inquiry into Child Sexual Abuse, the project gives individual victims and survivors a chance to be heard; to share stories in confidence, helping inform the inquiry’s investigation into the widespread failure of institutions from churches to boarding schools to halt abuse. So far it has collected more than 1,000 stories (and remains keen to hear more), and while the details are often harrowing, they are striking in what they reveal about the lifelong consequences. As one survivor says in the report published this week by the Truth Project, it’s “like pebbles thrown into a pond; the ripples keep on getting bigger”.

Last week, the World Health Organisation formally recognised the existence of complex post-traumatic stress disorder, a condition from which it is thought many survivors of childhood abuse suffer. It differs from other forms of PTSD in that sufferers tend to have “a completely pervasive and rigid negative belief about themselves”, says the inquiry’s chief psychologist Bryony Farrant. They may struggle with managing their feelings, trusting others, and with feelings of shame and inadequacy holding them back in school or working life. An analysis of Truth Project participants found that 85% had mental health problems in later life, including depression and anxiety, while almost half struggled with education or getting a job. Four in 10 had difficulties with relationships, with some avoiding sexual intimacy altogether, while others had multiple sexual partners; some suffered difficulty eating or sleeping, were dependent on alcohol, or were drawn into crime. One in five had tried to kill themselves.

Surprisingly, other research has shown survivors are at greater risk of illness, including heart disease and cancer, with years of chronic stress taking a physical toll on their bodies.

Farrant stresses that not every survivor’s story ends badly, and that their fates are certainly not set in stone. “I feel very hopeful and positive that people can recover, and certainly in my clinical work I’ve seen that,” she says. “The brain is far more plastic than we’ve previously understood, which means there are far more opportunities for people to repair some of the impacts from childhood trauma.”

But if a new technology, drug or junk food were doing such damage, it would be classed as a public health emergency. It is striking, then, that the toxic legacy of child abuse gets less attention than theories about whether social media makes teenagers anxious or skinny models fuel anorexia. “For me, this is the most public secret we have,” says Sarah Champion, Labour MP for Rotherham, a town still grappling with the aftermath of the child sexual exploitation scandal uncovered seven years ago. “I think people recognise and understand it, we’re just not prepared to confront it.” The Truth Project is trying to bring it out of the shadows.

Facebook Twitter Pinterest ‘I felt like a bad child, that I was doing something wrong’ … Sabah Kaiser. Photograph: Jill Mead/The Guardian

Kaiser remembers clearly the bedroom where it all started; at the top of the four-storey house she shared with her mother and five siblings (her father died when she was a toddler). After an older sister ran away from home, the room was left empty – and supposedly out of bounds – but she would sneak up. “In the room, there was a glass cabinet that had two shelves in – probably 4ft high – and books behind the glass. One on the train robbery, and a book about Tutankhamun. I’d sit crosslegged and just stare at my father’s books – never touch.” She was seven years old, she says, when a male visitor to the house first abused her there. Over the next six years, she told the Truth Project, she was assaulted by three other men, both in Britain and when visiting Pakistan. She always felt that to tell would put her mother in danger.

On the surface, Kaiser’s was a strict upbringing; if anyone kissed in a film, an adult would instantly switch off the TV. “There were no relationships outside marriage, no boyfriends and girlfriends of any kind, no untoward touching. Those lines were not blurred at any time. That act of touching, there’s so much onus on it – literally, the respect of the household is put on it,” she explains. “There were lines that were drawn, and then there were areas that were just ... no-go areas, and it was able to breed and occur as it did because there were no repercussions. Nobody saying stop.”

Years ago, in Pakistan, she heard a story that she didn’t understand at the time about a man caught abusing his toddler granddaughter. When the child’s mother confronted him, “she was beaten to a pulp. That was a no-go area. It was ‘you didn’t have the authority or the right, how dare you have the audacity to bring that up with me’. It was as if there was a place for men, and those men have their reasons.”

Initially, she interpreted the abuse as some kind of punishment, “like I was a bad child, that I was doing something wrong”. As she got older, she drew on her experience as a British Asian straddling two cultures to separate herself from what was happening. The girl at home enduring unspeakable things – withdrawn and always frowning – became separate from the popular, more assertive girl at school. “When I’m in my own home, the colours, the smells, the sounds are completely different. But once I step out of my door into the street, I’m in England, and everything looks and smells and sounds different. It was about being one person inside the house and, as soon as I stepped outside, I’m not that person.”

It was a school sex education lesson at 13 that finally provided words for what was happening. She walked out in the middle of it, and not long afterwards summoned the courage to tell her mother. The only time her voice quavers is when she describes her mother’s reaction.

“My mother was a seamstress, she sewed Asian women’s clothes. At any point of the day or night you would find her at her sewing machine in her bedroom and that’s where I went. I sat down on this little cushion by the gas fire and started to tell her. I didn’t quite know how to explain. The words I used were: ‘What a man and wife does in their bedroom to have children, is what he’s doing to me.’”

Her mother did confront the man, Kaiser says, asking if he had “touched” her. “He went into this tirade about how if I was raised in Pakistan, I wouldn’t be saying these things; how living in England ruins girls.” She realised that her mother was not going to back her up, and that in effect the subject was closed.

So she started fighting at school, skipping lessons, waiting for someone to notice. Someone did, but she says the teacher appointed to counsel her then abused her all over again; she was eventually taken into care aged 15, after months of shuttling between foster families and home. If new acquaintances asked about her parents, she would say she was an orphan. At 19, Kaiser found herself pregnant by an older boyfriend who had no idea of her history.

She struggles to forgive the social worker who, on learning of her pregnancy, told her to get counselling or she might abuse her own child. (Perpetrators are disproportionately likely to have been abused as children, but the idea of the cycle repeating itself is a sensitive one, says Farrant: “The research doesn’t support that abused people are highly likely to go on to abuse other people. Often it’s such a harmful narrative, and it intensifies the sense of shame and guilt.”)

With that warning ringing in her ears, Kaiser suffered postnatal depression after her son was born. “I could barely touch him; I couldn’t breastfeed him because I felt that every time I did, I was abusing him. I loved him so much, there was this fear that I was going to hurt him because there was something wrong with me.”

But she went on to have a second son, and this time it was easier, because she had learned that there were places not to go in her head. “If I didn’t close those doors, I’m not sure who would be talking to you today, it would be a completely different story. That’s what tends to happen to children like me. We become damaged goods, broken beyond repair.”

And yet she did not break. Kaiser now works as a translator, and volunteers for a survivors’ charity; she is proud of her two grown sons and is on good terms with their father, from whom she later separated. However, she has had another relationship that she describes as highly abusive, but realised during counselling that she was unconsciously mirroring her childhood experience. Adult survivors are, she says, vulnerable to predators because of their desperation to be loved: “I don’t think it ever stops shaping you. Just the impact is different.”

Facebook Twitter Pinterest Illustration: ALVA SKOG

What saved her, Kaiser thinks, was being reconciled with her mother in her late 30s. She won’t call it closure – “for me, it would be for my mum to say she believed me and that she was sorry, and she never said those words” – but it meant more to her than she can describe to be mother and daughter again. After years of anger, she now feels “love and respect” for her mother, wondering what experiences drove her response. “There was never a time when I didn’t feel her love. Even though there were times – years – when I didn’t feel it for her. I don’t believe for a second that she didn’t care.”

Two years after she got back in touch, her mother died, and when Kaiser subsequently saw adverts for the Truth Project, she felt ready to talk. “It was almost like I had chains around me, and it was her passing that made me feel I’d broken free.”

Survivors can choose how and where they talk to the Truth Inquiry as a way of returning the control that was brutally denied them as children (Kaiser deliberately picked a town four hours’ drive from home). They are asked beforehand about objects that might trigger disturbing memories, and staff adapt accordingly; if an abuser carried rosary beads, nobody in the room can wear beaded jewellery. Some people can’t ultimately go through with it and that’s fine, says Farrant. It’s no good rushing people who aren’t ready, since the impact of a “bad” disclosure can be immense. The inquiry has heard over and over again from survivors saying that being disbelieved or rejected was “just as, or in some cases more, traumatising” than the abuse itself.

Support workers will call before and after survivors share their stories to see how they’re coping and, if necessary, refer them on. Farrant is pleased that complex PTSD was officially recognised by the World Health Organisation, potentially leading to more research and better treatment for sufferers.

But beyond the auspices of the Truth Project, NHS mental health services remain overstretched, struggling with demand as historic abuse is brought to light. In Rotherham, Champion says there is a seven-month wait for the main specialist local abuse counselling service – and that’s the tip of the iceberg. “A lot of survivors can’t begin to unpick what happened to them. They’re just very aware that they struggle to hold down jobs or relationships, that they might have drug or alcohol dependency. A package to deal with those issues is needed.”

Meanwhile, as survivors become parents themselves, some are coming into conflict with the very social services that failed them as children. “There’s this assumption, particularly if they have been involved in gang grooming, that somehow they’re going to be a bad mother, whereas if they’d been raped [in other circumstances] people wouldn’t think that at all.” She wants a one-stop centre in Rotherham, bringing together multiple agencies under one roof to offer early support rather than “deal with the symptoms 10 or 20 years down the line”.

What she is talking about is essentially a public health approach, recognising the sexual abuse suffered by an estimated 7% of children as a significant hidden cause of mental and physical illness, just as tobacco is the underlying cause of many cancers.

If all forms of so-called Adverse Childhood Experiences (ACEs) – both sexual and physical abuse, or neglect – could somehow be eliminated overnight, the results would be transformative. Public Health Wales estimates it could reduce high-risk drinking by a third and heroin and cocaine use by two thirds, plus almost halving unwanted teenage pregnancies and slashing prison populations.

“When we know these things underpin the problems so many people are suffering, we’re really treating consequences, not causes,” says Dr Mark Bellis, director of policy research and international development at Public Health Wales and a leading expert on ACEs. “We don’t think about what’s driving people towards drugs; we might think about regulating access, when actually it’s the consequences of something that happened to someone as a child.”

Abused children often become hyper-vigilant, Bellis explains, knowing survival may depend on seeing trouble coming; and that affects both neurological development and hormone levels. “If your experience of life is fear, it’s not unusual to develop a more cautious approach to things. But there are physiological changes, too. The way I explain it is if you set any system on a high alert, it wears out more quickly. If it’s permanently running on high alert, it’s producing particular immunological responses or proteins which seem to be higher in people who are exposed to these traumas in early life.” Since these are also linked to higher rates of diabetes and cardiovascular disease, survivors’ risk of physical illness increases.

But that chemical response may also help explain why abused children who had at least one adult they could trust and relax around – leaving behind that state of high alert – seem to have better prospects of recovering. Other protective factors, he says, include feeling connected to a wider community or “if you can see a way out of things, being able to set your own destiny; if you feel you’ve got a pathway out, maybe through school”. It is important for survivors to know, he says, that there is hope. “The more we understand about things like resilience, the more we know there are things in children’s and in adult lives that can counteract this. You are not on a set course.” Children and adults do not have to be broken beyond repair. And it is not beyond society’s means to mend them.

Share your experience with the Truth Project at truthproject.org.uk, call 0800 917 1000 or email share@truthproject.org.uk.