In a new book, Janet Cresswell, who spent 25 years in the top security unit, reveals her dark world. By Sophie Goodchild

Her autobiography paints a bleak picture of how women are subjected to demeaning room searches, of drugged-up patients developing serious health problems as a side effect of their medication and of widespread self-harm among the female population who are held on draughty Victorian wards.

Ms Cresswell, now 74, was transferred into a medium-secure unit from the Berkshire hospital two years ago after spending nearly a third of her life with serial killers and rapists, despite the fact she had killed no one. The grandmother was sent to Broadmoor after attacking her psychiatrist with a vegetable knife, a serious offence but one that does not normally merit such long incarceration.

Her book, Ox-bow, also reveals how vulnerable female patients used to mix with serial rapists at hospital disco evenings arranged by staff. This practice has now been stopped after a former member of staff complained to the hospital authorities.

There are still 42 women at the hospital, despite a pledge by the authorities to move them to more suitable accommodation. Many have suffered sexual abuse in childhood and some have been sent to Broadmoor for their own safety because they are serious self-harmers. Increases in security at Broadmoor mean that these women are subject to petty privations on a daily basis, such as strict limits on how many possessions they can keep. They are kept on high-ceilinged Victorian wards which, mental health campaigners say, are not suitable for female patients.

The hospital trust has announced plans to move all female patients out of Broadmoor, either to other psychiatric units or to a new 70-bed site in Ealing, West London, which will open in 2007 subject to planning approval. The trust says that this will be "infinitely better" for patients. Some women have already been moved on, including one woman in her nineties who spent nearly 40 years at the hospital.

During her incarceration at Broadmoor, Ms Cresswell won a Koestler award for her writing, and her play The One-Sided Wall was performed at the Bush Theatre in London.

In her book, published by Chipmunkapublishing, Ms Cresswell says that although the rooms on the female wards have now been modernised "comfort and hygiene are out of the door" and that women are not even provided with proper toilets.

She writes: "When the house was re-decorated in 2002 urinals - seatless lavatories in mottled pink and pale mottled brown - were installed. The hateful mind that can insist on cold seatless lavatories for women is not fit to organise such a place."

Her book also highlights the fact that the needs of female patients have taken second place to those of the men. Although the majority of escapes from the hospital have been by men, Ms Cresswell describes how women have been made to suffer, with the installation of more than 2,500 security cameras for 400 patients.

The Independent on Sunday has highlighted the plight of people left to languish in high-security units because of a shortage of psychiatric beds. Ms Cresswell was repeatedly turned down for release from Broadmoor after refusing the supervision of a Home Office psychiatrist because, she argued, she was not mad.

In 2003, Broadmoor's former director of women's services exposed in graphic detail the abusive treatment of women patients at Broadmoor. Julia Wassell collected testimonies from female patients in the late 1990s which revealed that they had suffered sexual abuse and harassment. In an interview with this newspaper, Ms Wassell, who was dismissed after reporting her allegations to managers, said that during her time at the hospital women were used as "guinea pigs" to rehabilitate male patients and that women's needs were still not being met.