Lindsay Lohan allegedly displayed "classic psychotic behaviour" during her relationship with Samantha Ronson.
The DJ's mother Ann Dexter-Jones has admitted she "interfered" with the couple - who dated on and off from 2008 until 2009 - and told her 35-year-old daughter she couldn't support their relationship because she became "anxious about Samantha's safety and wellbeing" and even banned Lindsay, 26, from her home.
She told the Daily Mail newspaper: "When I saw myself just how volatile Lindsay was, I realised that the relationship was not healthy. I was seriously anxious about Samantha's safety and wellbeing. I feared tragedy. It got to a point that I wasn't sleeping very well."
The socialite turned jewellery designer became extremely worried when they were all at a party for the opening of the lavish The Atlantis hotel in Dubai in 2008, where Samantha was hired to DJ.
She said: "Suddenly, without any warning, Lindsay flung herself on to the thick carpet and started to roll around screaming like a child.
"It seemed she was upset that people, including Samantha, were not paying her enough attention.
"To my mind, it was classic psychotic behaviour. I took Lindsay aside and told her not to make a spectacle of herself. She was clearly out of control and spoiling for a fight.
"I told them I could no longer support them as a couple. I no longer approved on them being together and that Lindsay was no longer welcome in my home.
"I saw how much pain my daughter was in and the she was suffering deeply. She is a very Zen person and not used to the kind of turmoil that Lindsay seems to thrive on. I know stuff, but I don't want to go into it. I just knew that it was not a good place for my child to be."