Organisers of an Edinburgh Festival play about mental health have drafted in a psychologist for audience members who are affected by the performance.
The identities of the cast are hidden by masks
!Runners-The Return is a hard-hitting production showing at the Underbelly.
The use of the psychologist and the issuing of a disclaimer to the audience came after one woman complained of being distressed by the play.
A spokesman for the production said the "unusual steps" had been taken because of the "unusual show".
!Runners-The Return is billed as mixing a "riotous script of highly original writing with improvised spontaneity and audience participation".
The play puts actors and the public together as part of one large counselling session.
The interactive nature of the show means that the audience is invited to learn the history and personalities of the members of the fictitious Acorn Therapy Group.
The organisers admitted that they put the psychologist on standby and wrote a disclaimer highlighting the nature of the piece after an audience member stormed out on the opening night last week.
She complained to theatre staff about feeling uncomfortable and being distressed about the production.
From Monday, the disclaimer will be given to all audience members and explains that the producers cannot be held responsible if a member of the public suffers a "psychological episode".
David Mercatali, the director of !Runners-The Return, said that the mental well-being of the audience was paramount:
He added: "I suppose that we are in a unique situation in that we are perhaps the only play on in Edinburgh where having an audience member leave during a performance is a sign that we are hitting the mark, and confronting people with a controversial issue.
"However, the safety of our audience is vital, and the purpose of the disclaimer is to remind people that this is a work of fiction, and to complement existing procedures that we have in place."
Mr Mercatali said that the cast had been trained by psychologists to spot potential problems during the audience participation phases, and they have code words and alternative lines of script to use to "defuse any situations".
The play is the second in a trilogy by trained psychologist Cristina Teixeira.
The Brazilian-born writer expressed surprise at the controversy her work had produced in the UK.
She said: "In South America or in Europe, the performances of the !Runners trilogy have attracted a cult following, but it is only in Britain that a few audience members have taken exception to finding themselves interacting in a situation where mental illness is under discussion."
!Runners -The Return is being performed until 28 August at the Smirnoff Underbelly in Cowgate Edinburgh.