The Great British Bake Off star John Whaite has opened up on the severe condition that led to sister's disappearance.
The Bake Off 2012 winner, 31, made an emotional appeal online to find his sister, Victoria Cunningham, after she vanished abroad.
John joined the Loose Women to reveal how his sister was doing after being found 'just in time' in Portugal last week.
The celebrity chef wants to raise awareness for a very severe form of PMS called Premenstrual Dysphoric Disorder (PMDD).
Explaining how having PMDD led to Victoria's disappearance, he said: "Over the past seven years or since she had her first child, she has serious bouts of what we thought was post-natal depression.
“Then mum started to realise that she was dreading Victoria coming on her period, during that time, or the time around it, she would get very distressed. She’d become a different person. Straight away, two or three days after the period she’d be back to her regular self.
“Mum put her in touch with a consultant specialist in female hormonal and gynaecological health. That was the person who said, ‘I really think you’ve got Premenstrual Dysphoric Disorder (PMDD).’”
He explained Victoria was due to get on the plane home from Faro Airport in the Algarve when a PMDD-related breakdown occured.
John said: "It hit at the airport. She was due to come home and this moment of sheer panic and distress and anxiety hit and she just fled, she fled the airport.
"It’s very different for every woman; it’s case by case. One thing for Victoria is it makes her want to crawl out of her skin and get away from wherever she is.
"So she left. She dropped her passport and ran away. Our whole family just stopped. We just didn’t know what to do.”
John and the rest of his family feared for Victoria's life as she had "talked about suicide" in the past.
Of finding her, he said: "I put the appeal out, all the pictures of her were all over social media. My other sister and Victoria’s ex-partner, they went out to try and find her.
"Luckily, a stranger who lived in the apartment [near her ex] saw Victoria, recognised her from the photographs and pulled her in. If it wasn’t for that angel, we don’t know what would have happened."
John added: “She’s an amazing mother, she’s a fabulous sister – I hope she’s watching because I want her to know how much love and affection I’ve got for her.”
John, who used to present ITV daytime cooking show Chopping Block, thanked his followers on Twitter for helping to find his sister.
He tweeted: "I am delighted to say that Victoria has been found. She is alive, she is sober but she is very very distressed (it seems she was found JUST in time).
"A stranger recognised her and took her into her house. Each and every one of you, who has tweeted, shared and commented, has saved a life today. And I cannot thank you enough - you are all angels.
"We are now going to focus on getting her home and back in good health in the privacy and protection of our family. My gratitude to each one of you is undying. You’ve helped save a sister, a daughter and a mother - thank you."
This came after John posted an emotional video on Twitter where he accused the Portuguese Police of doing nothing to help in the frantic search.
He explained that his sister has "severe mental health issues" and was without a passport in Faro airport.
Speaking in the clip, he said: "She has depression, and she has been diagnosed by a consultant specialist in the field of female hormonal health as having PMDD or Premenstrual Dysphoric Disorder which is a disorder whereby she'll go pretty much insane during the week before and during her period.
"The result of these illnesses is that sometimes she goes on binges of drink and drugs, during which she'll sometimes show signs of self-harm and threaten to attempt suicide. She's vulnerable and at risk to herself.
"We love her dearly and just want her home."
*Loose Women airs weekdays on ITV at 12.30pm
