In the 1980s, Meredith Maran remembered her father abusing her. Years later, she wondered whether those memories were false…

When I was in my 30s, I accused my father of molesting me. I didn't see him or talk to him for eight years. I didn't let my children see him, either. And then I realised that it wasn't true.

In the late 1970s, a handful of feminist scholars had done some ground-breaking research and delivered some distressing news: incest wasn't the rare anomaly it had long been believed to be; it happened often, in normal families. A psychological phenomenon called repressed memory had allowed this to go unacknowledged, even unknown. As Freud had first asserted a century earlier, the impact of child sexual abuse on young psyches was so profound that victims often lost their memories, for years or decades.

These findings transformed incest from a dirty secret of family life into an obsession. In the 80s and early 90s, several cultural icons, including Roseanne Barr and Oprah Winfrey, went public as incest survivors. Incest memoirs hit bestseller lists. The Color Purple, a novel about incest, won the Pulitzer prize. Meanwhile, children were being removed from their homes, and parents were being sent to jail. Thousands of families were torn apart by accusations of sexual abuse, often made by adult daughters who claimed to have repressed, then recovered memories of childhood molestation by their fathers. Mine was one of them.

In 1982, when I was a writer and mother of two young children, I got a job editing a book by one of those pioneering feminist researchers. I was shocked and moved by what I learned. With missionary zeal, I spent the next few years writing exposés of child sexual abuse for newspapers and magazines. The more I learned, the more I felt I'd joined a back-room club. I found it all endlessly compelling: the newest incest study, the latest theory, the most promising new treatment. Conversations with my husband and friends seemed trivial in comparison.

One evening I was at a therapy group, researching an article, and as I sat listening to one of the accused men speaking, I heard a voice in my head. It was my father. I was 15 and he was yelling at my first boyfriend, Carl, saying, "She's mine! I'll kill you if you don't leave her alone."

And then I saw Carl yelling the same thing. Which version was real? Who was the violent one?

My father often lost his temper. He'd slapped me in the face more than once. But had that fight even happened? Was I making the whole thing up? Why had I left home at 17?

When I was a little girl, my dad was my best friend, and I was his. We had everything in common, including this: we liked each other more than either of us liked my mother. But as a teenager I'd lost interest in him. I'd met Carl and had been forbidden to see him. Just like that, my hero became my enemy.

My parents had divorced and my father remarried twice, settling in Puerto Rico. My mother had moved to an apartment nearby, but our relationship was strained, too, and it was a place I seldom went.

When I got home from the group that night, I couldn't stop crying. My husband, Robert, put his arms around me and for the first time in 10 years of marriage my body involuntarily recoiled from his touch. I cried myself to sleep on the couch.

I started having dreams – about incest, about my father – but how could I tell whether they were based on memories? I saw a series of therapists, and my marriage fell apart. Around the same time, I surprised myself by falling for a woman, Jane, whom I'd met through work. Like everyone else with whom I'd surrounded myself, she was an incest survivor.

My father and I hadn't lived on the same continent since I'd left home. Now he and his wife, Gloria, a woman six years older than I was, announced they were moving nearby, to spend more time with his grandchildren. "Better late than never," my brother said to me, sarcastically. His kids, Emmy and Zach, were six and eight; mine, Matthew and Charlie, were six and seven. Our father was the only grandfather they had.

As my father's arrival neared, I started feeling hopeful. Maybe having him in my life again would bring us closer, and quash my fears.

Sure enough, my first thought when I saw him was, "He couldn't have."

"How can you leave your kids with him?" Jane asked me. "Don't you think you should tell your brother?"

"Tell my brother what?" I said. "I still don't know what happened."

"You have to believe yourself," Jane said. "Feelings don't lie. Dreams don't lie."

I didn't tell my brother. Instead, I watched my father warily whenever he was with my children, and I gave them baths after days they spent with him, surreptitiously inspecting their bodies.

One evening, I was driving Matthew and Charlie home from a sleepover at Grandpa's when Matthew said, "Grandpa got mad at Charlie and threw him down on the couch really hard. Charlie cried."

I saw red. When they were asleep, I called him.

"You know how kids exaggerate," he said.

Where had I heard that before? Oh yes: from the child molesters and incestuous fathers and ritual abusers I'd interviewed and read about for years.

The next time Gloria called to invite the kids over, I told her from then on I was going to stay with them while they spent time with her and my father. She didn't ask why. I didn't tell.

Then my father and I got into a phone argument about my relationship with Jane.

"It's not legitimate in my eyes," he said, "or in the eyes of the law."

"I thought you liked Jane," I said. From my first boyfriend to the husband I'd divorced, my father had ignored, mocked or scorned everyone I'd loved. He was doing what he'd always done: punishing me for loving someone else.

"I can see how damaged your children are," he said. "They are disturbed by your homosexuality."

My life with my father flashed before me. The childhood years of wanting and worshipping him. The adolescent years of battling him. The adult years of missing him. And the past few years of suspecting him. Now I knew the truth. He didn't care about who I was or what I needed. He cared only about how I made him feel. Of course he was capable of using me for his own pleasure, discarding me when he was through. He was doing it now.

My incest nightmares weren't fantasies. They were memories. My father's big, blunt hands. The wiry, black hairs on his knuckles...

"You're wrong about my kids," I said. "You're wrong about me."

"You never could stand to hear the truth about yourself," he said. "That's why you surround yourself with weak-minded people who don't question you. I'm the only one who knows the real you."

"Don't ever call me again." I slammed down the phone.

I joined a counselling group for incest survivors and read The Courage To Heal, a new book that was a bible for the recovered-memory movement and went on to sell 2m copies. It was full of personal stories, checklists, advice on how and when to reveal the truth. Now it was time to tell my family.

I asked my brother to meet me for dinner.

"I'm pretty sure Dad molested me," I said.

I pulled out a list – "What Makes Me Think I Was Molested" – and read it to him, watching him wrestle with what I was saying. "I know this kind of thing happens," he said. "I just never thought… "

My sister-in-law called me at seven the next morning. "I'm so sorry," she said. "Is there anything I can do?" I felt so relieved. All those horror stories of incest survivors being disbelieved by their families: that wasn't happening to me.

"Doug and I were talking," she went on. "Do you think it's safe to leave Emmy and Zach alone with your dad?" I saw them with my boys in my father's apartment: laughing at his bad jokes, drinking forbidden cans of Pepsi. I'm ruining my family, I thought. And I'm not even sure why.

Believe yourself, I heard my lover and my therapists saying. If you think you were abused and your life shows the symptoms, then you were.

"No," I told my sister-in-law, "I wouldn't leave your kids with him, if I were you."

I went to see my mother, and told her what I believed.

"When you were two years old," she said shakily, "he told me you looked too sexy in your bathing suit. He was so angry. His reaction sickened me. I didn't know why." Oh my God, I thought. It's true: I really am an incest survivor.

"How could I have let this happen to my baby?" she wept. Then her mood changed. "What you're saying is impossible. Your father couldn't have done that to you. He didn't even like sex with me."

She called first thing the next day. "Your father had his failings. But there's no way he could have done something like that to you." She paused. "He loved you more than anyone else in the world."

"I'm sorry this is so hard on you," I said.

Not long after, my father left a message on my answering machine.

"Hello, Meredith," he said. "I'm wondering if you're ready to resume our relationship."

I didn't call him back.

By 1990 I'd been following the instructions in The Courage To Heal for two years. I'd cut off all contact with my father and kept my children away from him. But I realised I needed to stop writing and reading about incest, to stop all the therapy and spend time with old friends again, go out for drinks and to films that made me laugh instead of cry.

It worked, for me. But as my nightmares and memories receded, Jane's were becoming more graphic and disturbing. She remembered being raped before she was five years old. She remembered men and women standing around a campfire in a forest, chanting, wearing dark robes.

By that point, there were dozens of satanic ritual abuse cases reaching the courts. But there was also a backlash growing, led by the False Memory Syndrome Foundation, and the same newspapers and TV shows that had covered the incest stories were jumping on the bandwagon. Therapists were sued for implanting false memories, stripped of their licences and ordered to pay settlements. Convictions were overturned, the accused set free.

Not for the first time, I started to doubt myself. Had I created my incest memories? Six years earlier I'd told my brother and his wife not to leave their kids alone with my dad. Now, I said, I wasn't so sure. It was a relief to admit that. I'd been finding Jane's stories of ritual abuse harder to believe, too. Eventually, we split up.

My father had a heart attack, serious enough to make me realise I had to stop this while there was still time. Whatever my accusation had been when I'd made it – a statement of truth, of truth as I'd seen it then, of solidarity – it was something else now. Quite possibly, a matter of life and death.

I considered showing up on his doorstep, but I was afraid he'd turn me away. Instead, I sent a card. He replied, saying he was ready to see me.

He was greyer than I remembered. Balder. Shorter. He'd been so much bigger in my head. Every time I tried to talk about what had happened, he changed the subject. We spent the afternoon, and the next several years, that way: no questions answered, no questions asked. And then, just when I'd fully regained my mind, my father was diagnosed with Alzheimer's disease and began to lose his. I was left with two options. I could hope he'd forget the wrong I'd done him, along with the other details slipping through the fissures in his brain. Or I could convince him to have a conversation with me about what I'd done and why I'd done it – and how sorry I was.

I went to see him. "When it happened," he said without preamble, "I thought you'd come to your senses in a few days." He frowned, grasping at memory. "But then I kept calling you, and you wouldn't talk to me."

I swallowed. "I never forgot about you, Dad."

"I called your mother, too. I asked her if there could be any truth to what you were saying."

Oh my God, I thought. If he's not sure he didn't do it, how can I be sure? "And that's how you decided you didn't molest me?" I asked.

"You know how it is," he said. "You hear something often enough, you start to believe it's true."

"Oh, yes," I said. "I do know how that is."

• Some names have been changed.

This is an edited extract from My Lie: A True Story Of False Memory, published by Jossey Bass on 20 October at £16.99. To order a copy for £14.44 (including UK mainland p&p), go to theguardian.com/bookshop.