Ann Dally was a pioneer in psychological medicine who took a particular interest in the treatment of long-term drug addicts. She believed that the medical establishment was effectively sending many people on to the streets by refusing to administer gradual withdrawal programmes that would help them to become drug-free. She set up a private Harley Street clinic with her psychiatrist husband, and at one stage was treating about 150 long-term addicts.

However, her treatments brought her into conflict with the General Medical Council, which took action against her several times. She successfully fought against being struck off but was banned from prescribing controlled drugs, effectively forcing her to retire from medical practice.

Ann Gwendolen Mullins was born in 1926, the daughter of the London magistrate and law reformer, Claud Mullins, and Gwendoline Brandt, from the German banking family.

She was educated at Dalton School in Epsom and the Beltane School in Wimbledon, both run on progressive lines; then Wychwood School, Oxford, from where she was expelled for being a “bad influence” and told by the principal that she would never be good at anything. However, her education continued at Oxford High School, thanks to the efforts of her father and Miss Stack, the principal.

In 1942 she won an open exhibition to Somerville College, Oxford, where her undergraduate friends remember her as very bright, opinionated, untidy and indifferent to fashion. Janet Vaughan, the new principal, befriended her and discovered her childhood yearning to be a doctor, partly inspired by the fictional Dr Dolittle. After completing her history degree she spent a year lecturing British forces in occupied Austria and Germany.

In 1947 she entered St Thomas’ Medical School as one of its first three women students. Here she met Peter Dally whom she married two days after their preclinical exams. She gave birth to two children by the time she qualified and found a house job with Alexander Kahan, one of the few physicians willing to supervise a woman doctor with family commitments.

Ann Dally enjoyed medicine with a social slant, got to know patients well by active listening and observation, and was a critical thinker, despite the euphoria of working in the new NHS. Kahan encouraged her, as a general physician, to “do your own psychiatry”, rather than ignoring the needs of patients with emotional problems as so many GPs did.

She worked as a hospital doctor until 1959 when she combined part-time general practice, family planning and baby clinics, medical journalism and broadcasting. While bringing up her six children she wrote about maternal and childcare and her books included The A-Z of Babies, Inventing Motherhood: The Consequences of an Idea and Why Women Fail.

She was drawn to work with her husband, a psychiatrist, in a partnership that endured beyond the end of their marriage in 1969. Doing private practice enabled them to work intensively with needy patients.

As well as being vilified for working privately Dally was later occasionally accused of not being a proper psychiatrist, because she took on psychological cases but was not eligible for the Diploma in Psychological Medicine. From 1980 Dally was referred an increasing number of opiate addicts. She saw the addiction as an attempt by her patients to cope with their lives; keeping them in work and able to cope with their families was the priority.

Maintenance treatment for opiate addicts had became particularly contentious, with new Department of Health guidelines which favoured rapid dose reductions and discriminated against the minority of long-term addicts who were unable to reduce and stop using opiates. These patients were turned away by NHS drug dependency units. If not able to find a practitioner willing to supply maintenance treatment and help with a gradual withdrawal programme, they were at the mercy of the black market, with contaminated drugs, shared needles, and risk of bloodborne diseases such as hepatitis and Aids. Their lives were once more risky, chaotic and dominated by funding their drug habit.

Dally championed their right to treatment using her reputation as a journalist as well as a trusted practitioner, forging strong links with Home Office officials and like-minded doctors and lawyers.

She was asked to act as a drugs treatment adviser to the Prime Minister, Margaret Thatcher, whom she had known at Somerville, and she was a member of the committee that drew up the 1984 Guidelines on Treatment of Drug Misuse.

However, she found that the guidelines set perverse incentives for practitioners, and attempted unsuccessfully to produce a minority report and fell foul of the GMC on several occasions.

“Had I kept silent and simply treated patients, as other doctors did, I might never have got into trouble”, she wrote in A Doctor’s Story(1990). She railed against the hypocrisy and discrimination she encountered in her dealings with the GMC and medical establishment and was appalled by what she called the “phoney war on drugs”.

The controversy about medical treatment of opiate addiction has not gone away, though medical education avoids the subject less than previously and more evidence is now available to back a range of treatment options.

After retiring from her practice, Dally became a medical historian at the Wellcome Institute for the History of Medicine, producing Women under the Knife (1991).

She is survived by her second husband, Philip Egerton, whom she married in 1979, and by two sons and two daughters. Two sons predeceased her.

Dr Ann Dally, physician, was born on March 29, 1926. She died on March 24, 2007, aged 80