'In the field of psychiatry, the interest in patients' dreams has progressively fallen out of both clinical practice and research,' said Silvio Scarone, of Universit? degli Studi di Milano in Milan.

'Basic dream researchers could now apply their knowledge to psychiatric patients with the aim of building a useful tool for psychiatry, reviving interest in patients' dreams,' continued Scarone.

'Neuroscience investigators could explore how to extend their work to psychiatric conditions, using approaches from sleep research to interpret data from acute psychotic and dissociated states of the brain-mind.

'Exposure to real threatening events supposedly activates the dream system, so that it produces simulations that are realistic rehearsals of threatening events in terms of perception and behaviour,' said Scarone.