ADT lowers testosterone levels, but this also seems to have an impact on the patient’s chances of developing dementia or Alzheimer’s disease years later.

In the new study, researchers from Stanford University tracked the progress of 1,829 prostate cancer patients for five years after they had been given ADT. In that time, 7.9 per cent developed dementia compared with 3.5 per cent of other prostate cancer patients who weren’t given ADT. “The risk is real and depending on the prior dementia history of the patient, we may want to consider alternative treatment,” said lead researcher Dr Nigam Shah.

The risk was greatest among men who were aged 70 and older and who had been taking ADT for at least a year.