Imagine awaking in the middle of the night to find your partner trying to make love to you - while they are sound asleep.

"Sleep sex" is a term coined by US scientists to describe the phenomenon, which can cause people to commit sexual acts on themselves or their partners - while asleep.

The condition can range in severity from disruptive moaning to unwanted, and sometimes violent, sexual advances to their partner.

But no matter how serious their night-time behaviour, patients did not remember what they had done the next morning.

The Stanford scientists, whose research is published in the journal Psychosomatic Medicine, believe the condition is caused by a sleep disorder combined with emotional problems.

Police called

Christian Guilleminault, professor of psychiatry and behavioural sciences at the Stanford School of Medicine, studied 11 patients, grouping them according to the seriousness of their symptoms.



People have to realise that it's a medical problem and there is a treatment

Professor Christian Guilleminault, Stanford University