By Jane Elliott
Health reporter, BBC News
For two weeks every month Sue Scarlett used to become what she calls a "raging monster".
Sue was so depressed she considered suicide
Normally laid back, Sue, 37, from Essex, became terrified by the changes that came over her for half her life.
She would spend days weeping for no reason, flying into irrational rages and even contemplated suicide.
"My symptoms started getting really bad when I was 27, but I thought it was the relationship that I was in that was making me feel weepy, anxious and generally very sensitive at certain times," she said.
"I noticed that for half the month I could cope with the stress and was a happy-go-lucky, very strong, full of fun character.
"But then the other half, I was extremely insecure and some days I could not face the world.
"I felt like killing myself. I had this anger that absolutely overwhelmed me."
Sue was so worried by her lack of control that she ran away, but her supportive family and new boyfriend found her and brought her back.
It was boyfriend Dan who noticed a pattern in her behaviour.
Four-and-a half years ago, he suggested Sue, a trainee solicitor, should enrol in NAPS (National Association for Premenstrual Syndrome).
They suggested Sue kept a diary, and she was later diagnosed with premenstrual dysphoric disorder (PMDD), which was leading to the weeks of pre-period symptoms.
She says: "NAPS was a complete godsend, as I realised I was not alone.
"Before this I had found very little information to help me. I think I was totally obscured by my condition. I used to be so in control of my life before.
"I had travelled the world twice and knew Buddhist techniques to keep me calm. But in these two weeks I would have a rage bubbling inside me that had to come out."
Sue was prescribed both oestrogen patches and progesterone tablets, but these exacerbated her symptoms.
Her doctor then gave her a six-month testosterone implant.
Up to 95% of women having periods have PMS symptoms
"The result was I nearly committed suicide. I became such a raging monster.
"The testosterone made me really feisty and it was like I had permanent road rage, shouting at people, driving fast, behaving aggressively.
"One day my partner and I were driving somewhere and as well as shouting at everyone on the road I was shouting at him for over an hour at the top of my voice.
"My head felt like it was going to burst and I pulled the car over and punched the dashboard so hard so many times I bruised all my knuckles.
"I shouted I had had enough and wanted to open the door and throw myself in front of a car.
"I had already contemplated ending it by throwing myself off our flat balcony."
Dan managed to get Sue home and together they researched natural remedies.
They discovered that eating carbohydrates every two-and-a half hours helped balance her moods and increase her serotonin production. Vitamin B12 was also a great help in keeping her nervous system balanced.
She also asked her GP for a mild anti-depressant, avoided alcohol, exercised more, took multi-vitamins and ensured she got a good night's sleep.
Sue says the results have been dramatic.
"I have managed to reclaim most of my life.
"I do still have severe PMS at times but generally only for about five days, and nowhere as bad as previously. I can still get ratty, but it has been made bearable."
Sue and Dan have stayed together throughout her ordeal and plan to marry later this year.
Up to 95% of women having periods have PMS symptoms, and the NAPS estimates the condition severely affects the daily lives of around a third of them.
Nick Panay, consultant gynaecologist at Queen Charlotte's and Chelsea and Westminster Hospitals, London, and NAPS chairman, said it is important women get themselves diagnosed.
He said symptoms could vary dramatically from mild irritation to literally murderous rages.
"Comparing mild PMS to severe PMS is like comparing chalk to cheese," he said.
"But there is a lot that can be done for women with PMS, either with medicines or psychologically.
"The first stop is for women to see their GP and to look at the NAPS website for advice about clinics."