Ecstasy could be taken by autistic adults to help them open up in social situations, researchers say.

The street drug - also known by its medical name MDMA - is thought to encourage a positive mood among strangers and lessen awkwardness.

Rising in popularity in the the late 1970s and early 1980s among a circle of underground chemists, therapists and psychedelic drug enthusiasts, it later became infamous as the drug that fuelled all-night raves.

But the side-effects remain positive and the drug is known to increase energy, euphoria, emotional warmth and empathy toward others.

Drawing on these psychological responses, researchers are planning their first study using MDMA for the treatment of social anxiety, as outlined in the journal Progress in Neuro-Psychopharmacology & Biological Psychiatry.

It is hoped that ecstasy will be administered infrequently in clinical settings to reduce this nervousness and improve the relationship between an individual and their therapist.

The use of MDMA as a potential treatment within a clinical setting has been investigated for a number of years, PsyPost has reported.

Between 1996 and 2012 in England and Wales there were 577 deaths in which ecstasy/MDMA was recorded on the death certificate.

But MDMA is considered to be safe and non-addictive in small doses and controlled environments.

The drug has been illegal in the United States since the 1980s but before this, it was tested for possible therapeutic effects and was noted for its ability to promote positive mood.