Andrea can't now put a finger on exactly what first drew her to Michael, except perhaps his singing voice and his neediness. "Whether love was involved, I don't know," she says. "I set up a bank account for him, and he moved in."

Michael hadn't yet completely wrecked his performing career. While his violent mood swings and abusive behaviour had alienated him from the wider music industry (well beyond its usual tolerance for lunatics), he still had support in Ireland and was looking for a new direction. With Andrea, whose clout as a producer was sufficient to make it happen, he cooked up the idea of composing a musical about Brendan Behan - the made-to-fit hero for self-destructive, alcoholic Irish wordsmiths. Michael said he would draw on his father's alcoholism for inspiration.

Andrea remained blind to Michael's own drinking and drug abuse; she even managed to block out his violence against her. Her only explanation is that, having herself grown up with a mentally disordered mother, her ability to identify abnormal behaviour was very poor. Looking back, Andrea cast herself in the mould of female "enabler", supporting a man and his pain regardless of the cost to herself. Michael fitted another Irish type. "The kind they'll talk about in Dublin as 'a bit touched, a bit mad, but a genius,'" she says. "It's pathetic."

By facilitating the Brendan Behan show, in which Michael was to star, Andrea was performing the ultimate act of enablement: allowing him to live out the fantasy of becoming his childhood hero and nemesis. Psychiatrists had already diagnosed him as having depression, but nothing more. Irish taboos about childhood abuse and alcoholism were left well alone. Only much later, after the intervention that would save his life, did it become apparent that there were deeper forces at work, ones that had been incestuously mingled between generations. Not only Michael's father but also his grandfather had been alcoholics, and between these two there also lay the shadow of a doubt about which one was Michael's actual biological father.

The musical turned into farce. At rehearsals, Michael would turn up paralytic and abuse his financiers; he physically assaulted Andrea on set, in front of the cast. It was only then that her eyes were opened to what had been happening all along. He left empty whiskey bottles in his pockets and destruction in his wake. When Andrea told him that his abuse of cast and commissioners had destroyed the production, he smashed up their house as well. She recalls refusing to argue any more and watching as he continued the fight alone, acting out her voice as well as his own. Typical enough, she says, of someone with a narcissistic personality disorder.

As he plummeted into what might have been a suicidal binge, Andrea attempted to disengage. But a Dublin psychiatrist demanded to know why she was not "to hand". He wanted her to sign section papers, committing Michael to a psychiatric ward. Yet she realised this would just push her back into the role of taking responsibility - of enabling him to keep destroying himself.

Instead, another idea came to her from a drug rehabilitation centre in Arizona. There might be a way of persuading Michael to take responsibility himself, through the vehicle of a last-ditch intervention, in which an addict is confronted with the reality of his actions. The "special projects" director of the Arizona clinic told her this was advisable only when there was no other option, and the addict was approaching final destruction. But he also warned her that she mustn't do it hoping for a particular outcome. It might help Michael turn the corner to recovery, but it might also speed the journey to suicide. Her participation would have to be an act of generosity.

Michael needed to be tracked down by a private detective and tricked into turning up in a hotel room, where Andrea, a medical professional and the director of the Arizona clinic would converge. On the day, Michael opened the door like a famine vagrant: gaunt and green. The clinic director later said he'd have given him three to six weeks to live. He spoke, intensely and hypnotically, for five hours, during which time Michael barely uttered a word. Finally, the interventionist invited Andrea into the room. "I want you to look up at this woman," he demanded. "What do you make of her?"

After a deafening silence, Michael raised his head. "I don't know anyone I'd rather be buried next to," he said, and agreed to go to Arizona.

Not drinking was just a start. Neither Michael's past nor his personality disorder is going to vanish, and his marriage to Andrea remains functional rather than intimate. But while he'll never write as well as Behan, he's better than he used to be, and he's alive.

· Names and details have been changed.