AS MANY as one in 20 people may be suffering a form of depression that cannot be treated. Sufferers may experience up to 20 attacks a year, none lasting for more than a few days, and occurring every one to five weeks. The World Health Organisation has recognised this 'recurrent brief depression'.

While GPs realise their patients are seriously ill - some are suicidal - by the time they see a psychiatrist they may appear to be better. Dr Stuart Montgomery, a consultant at St Mary's Hospital, London, says in the newspaper General Practitioner: 'Patients make the same suicide attempts, have the same impaired ability to work and the same destruction of relationships' as people who suffer from long-term depression. Men and women are equally affected and there is no link with the menstrual cycle for women.

Conventional drug treatments do not work, and some antidepressants even seem to make the condition worse. If patients are told they will be better in a few days, they can often cope by battening down the hatches and doing nothing until the depression lifts.