Most people associate obsessive compulsive disorder (OCD) with simply being a "neat freak", but in reality the condition is far darker and can leave sufferers paralysed with fear.
Journalist and author Bryony Gordon, who has lived with the condition for the past 22 years, is often convinced she has inflicted harm on those she loves the most,
"It is like something telling me I'm the worst human being in the world: that I may have poured bleach in my daughter's drink or have done something awful to her in the middle of the night and blocked it out," she tells The Huffington Post UK.
"It's not just the trivial things that everyone makes it out to be."
OCD is an anxiety disorder, characterised by obsessions and compulsions.
Obsessions are intrusive, unrelenting thoughts (often dark and anxiety-inducing). Compulsions are repetitive activities a sufferer feels they have to do to prevent the obsessions becoming a reality - these can be overt, such as washing hands, or covert mental rituals, such as repeating the same phrase in their head.
"OCD is like your brain refusing to acknowledge what your eye can see. Whether that you haven’t left the oven on, you haven't abused your own child," she explains.
Gordon also suffers from depression, which she says is brought on when her OCD intensifies. She first started experiencing it aged 12 and was put on anti-depressants aged 17.
Gordon has long been known for her openness, in both her columns for The Telegraph and best-selling debut book, 'The Wrong Knickers', but it wasn't until last January 2015 that she "came out" publicly about the full extent of her mental health.
"I was sitting at my desk, fighting back tears and thought: 'This is fucking ridiculous. If I had the flu people would say go home, go to doctor, take this. I have this column, which has always been quite personal, why am I not talking about the most personal thing of all?'"
The response was overwhelmingly positive, with readers sending emails and tweets to thank her and share their own stories. She knew at that moment that she had to keep writing about mental health.
That's why Gordon decided to write her book 'Mad Girl: A Happy Life With A Mixed-Up Mind'.
Starting with her first experience of OCD, when she became convinced - aged 12 - that she would die from AIDS, the book charts her journey to the present day recounting, with unflinching honesty, details of her eating disorder, an abusive relationship and countless cocaine binges.
But despite the heavy topics, Gordon manages to maintain the humour and exuberance she is so well-known for, recounting, for example, the time she went to work with the iron in her handbag to be sure she hadn't left it on or her decision to name her OCD, Jareth the Goblin King, after David Bowie's character in the cult film 'Labyrinth'.
"I wanted to write an upbeat book about depression, I didn’t want to write a misery memoir," she reveals.
Gordon is also clear that 'Mad Girl' is not a self-help book. "I spent years not being able to help myself," she says.
Recently, Gordon has learned how to manage her own mental health better. Rather than self-medicating with drugs and alcohol, she recently started CBT and living a healthier lifestyle, including exercising regularly and eating well. She also knows what triggers her OCD: "If I’m stressed out or tired it will find a vulnerable crack, crawl in, and exploit that."
Ironically, she fell ill again while writing 'Mad Girl'. She says that writing a book is "the writer's equivalent of taking part in a marathon", and blames long nights, copious cups of coffee and the fact that she also moved house, for prompting her OCD and depression to rear their ugly heads.
But it was while dealing with her mental health again most recently that she had a Eureka! moment, and 'Mad Girl' became the spring board for something greater.
While out for a run in a bid to get some endorphins pumping through her veins, Gordon tuned into a podcast and was inspired by a quote from Carson McCullers, an author who suffered from depression, was an alcoholic and died at just 50 years old.
The podcast ended with some archive footage of McCullers saying: “All people belong to a We except me”. It spurred Gordon to seek out her own “We”, other people with mental health whom she could relate to and speak openly with.
Later that evening Gordon sent a tweet, asking if anyone would be interested in having a mental health meet-up every so often in London to walk, talk and have tea. And just like that Mental Health Mates, an informal peer support group, was born.
The first event was at the Serpentine Gallery on Valentine’s day, which can be a particularly tough day for people, especially in a big city. Gordon says she expected just two or three people to show up, but was ecstatic when 20 people arrived.
Mental Health Mates is intended as a low-key and non-judgemental space for people with mental health issues to make connections and talk about anything they choose, be it the pros and cons of various anti-depressants or discussing the latest episode of 'Game Of Thrones'. But then, she says, if you don't want to say anything that's totally fine, too.
The June meeting took place in the beautiful setting of Queen Mary's Gardens in Regent's Park.
"I’m trying to replicate AA meetings but out in the open," she says. "I think the model is brilliant and it is a great network for people. They know at any point they can go and find a meeting and be with like-minded people and that’s a really powerful thing."
Gordon is keen to stress that anyone is welcome - one man even came to Mental Health Mates with his nine-year-old daughter and his wife - and the groups are discreet. "You’d think we were just a uni reunion group or something, it just shows you that it is very normal to feel weird," she says.
Kat, 30, is a regular at Mental Health Mates events. She has generalised anxiety disorder (GAD) and panic disorder, which she believes started in childhood, but she wasn't diagnosed until 2010.
Initially she says it was a "Sunday distraction", but now she has made firm friends with some of the other attendees and, as well as the regular meet-ups, they attend a pub quiz together and plan other meet-ups, such as cinema trips.
Kat says that while her family and friends are extremely supportive, none of them have mental health issues and so can't fully appreciate how she feels.
"Imagine a top set maths student trying to explain Pythagoras Theorem to a bottom set student," she tells HuffPost UK at the June meet-up. "Because if you don’t have a mental illness you can only understand a person with one so much, but this is not in any way a reflection of how much you care."
Kat says that sometimes when she's expressed her darkest thoughts, her friends and family have grown concerned for her safety.
"For example, on a daily basis when I go to bed the recurring thought in my mind is that I don’t want to wake up," she explained, admitting that she suffers from incredibly low self-esteem. "This is driven by my internal monologue which states that I am not good enough, as a friend, a daughter, a person, an employee. I often think no one would care if I wasn’t there and that I am only constant disappointment and embarrassment to people in my life."
When she told this to her family, they were understandably alarmed, but when she told the Mental Health Mates, many of them could empathise.
"Obviously I know I should let someone know if I’m struggling (and the same goes for anyone having issues) and that I shouldn’t believe those thoughts, but the benefit of Mental Health Mates is that I can be brutally honest about how I feel without fear of judgement or upset."
This is something echoed by Gordon. Mental Health Mates is not supposed to take the place of therapy or medication, it is simply a safe space for people to meet and feel like they can be entirely themselves.
Mental Health Mates is a key part of her larger mission: inspiring and encouraging people to speak out and to de-stigmatise mental health.
"People don’t need to suffer in silence, they really don’t. The more you suffer in silence, the worse it gets - because of course mental illness is all in your head," she says.
"When I was 12 I had this thing and I didn’t know what it was because I had no words for it and it had all this power over me. But when you start to get words for something, it has less power over you."
Samaritans offers a listening service which is open 24 hours a day, on 116 123 (UK and ROI - this number is FREE to call and will not appear on your phone bill.)
Mind, open Monday to Friday, 9am-6pm. Call 0300 123 3393.
Get Connected is a free advice service for people under 25. Call 0808 808 4994 or email: firstname.lastname@example.org
HopeLine runs a confidential advice helpline if you are a young person at risk of suicide or are worried about a young person at risk of suicide. Mon-Fri 10-5pm and 7pm-10pm. Weekends 2pm-5pm. Call on 0800 068 41 41.