Letter: Courting danger with 'recovered' memories

Sir: The award of damages to the Californian father falsely accused of incest by his daughter (report, 16 May) is the most recent example of the problems that can arise in psychotherapy when memories are 'recovered' that may, or may not, be fantasies.

The distinction is particularly difficult to make when hypnosis is used to enhance recall. Psychologists working with hypnosis in an experimental setting are familiar with a common result when they ask hypnotised subjects to recall previously learnt material: on those occasions when their memories fail, especially if the hypnotist is ardent and supportive, subjects will resort to invention. Plausible answers will be produced without any external indication that the subjects are faking; indeed, they themselves may be completely unaware that what they are apparently remembering is untrue. With further urging from the hypnotist, the fantasies will typically be expanded.

The untrustworthiness of such recall makes the use of hypnosis with witnesses in court cases a very risky procedure. And in the case of psychotherapy it is surely obvious that hypnosis should be utilised only by those with training who are aware of the many pitfalls and who do not allow their own preconceptions to direct their patients' search for previous traumata.

Yours faithfully,

DEREK FORREST

Trinity College

Dublin

17 May