If you saw me walking down the street, you would think I was a typical thirtysomething Londoner. But I have been carrying a secret with me for 20 years. I have been living a double life, witnessing extraordinary things.
For my day job, I work as a TV producer, making documentaries. But behind the scenes in my world, there are aliens, goblins and spies. These creatures have plagued my family for a long time and we have been desperately trying to make them go away.
They invade our lives because of a mental illness called psychosis.
I'm a middle child, with two brothers, and my family encountered our first aliens back in 1995. My parents had to bring my older brother home from university. He was emaciated – he's 6ft tall but only weighed six stone. He'd been watching famine reports on the TV and voices told him that it wasn't fair for him to eat. He thought our parents were aliens and was experiencing hallucinations – both visual and auditory. He was having a psychotic episode and was eventually diagnosed with schizophrenia.
My older brother was the academic one, brilliant on computers and incredibly artistic. He would programme games on the ZX Spectrum and we'd all feature as characters. He loved to skateboard and was a proud geek. He was our hero. My younger brother – 16 at the time – was the smart, cool and practical one. He loved hip hop and electro and we'd all breakdance on the giant pieces of lino he'd drag into our back garden. I know he suffered more than me during our older brother's illness. I was at university so had some protection and distance from the daily battle to bring my brother back to sanity.
Psychosis is a medical term used to describe a range of symptoms, including hearing or seeing things, or holding unusual convictions. Examples range from the belief that people are out to get you in some way (paranoia) to the belief that you are a king or religious deity (euphoria). People who have a mental illness such as schizophrenia, bipolar disorder, postpartum psychosis and psychotic depression experience some or all of the symptoms of psychosis. But there are many other illnesses that can lead to a psychotic experience.
My parents never gave up on my brother and over the years, with medication and a lot of talking, he came back to us. It took 10 years to get him to a place where he could get a job and engage with the world again. That's enough time to lose a lot of friends and damage the potential you once had.
Psychosis affects 3 per cent of the population at some point in their lives. It's more common in young people than diabetes. So I am definitely not alone in my experience of this illness, although it can feel like it sometimes.
When someone you love changes in this way it can feel like bereavement, but it's a complicated experience, because the person is still standing there in front of you.
In 2009, something happened that we really weren't expecting. I got a call from my mother to say that my younger brother had been picked up by the police and taken to a psychiatric hospital. He was found walking the streets, trying to stop cars, with a cardboard plaque around his neck appealing for help. It was a total shock, because my younger brother was usually so together in the head.
I remember travelling home, feeling sick to my stomach. We'd been through this with my older brother. How could it be happening again? My younger brother's manifestation of the illness was different. He wasn't hallucinating, but experiencing what are known as "thought disturbances". He believed that people were trying to warp his brain via the computer and TV (some would say, not such a delusion) and he was being followed and monitored by strange forces.
There is no one single cause of psychosis, although scientists believe that genes, biological factors and environment all play a part. I tried to think what could have caused this. He was helping to look after my terminally ill father while studying for a degree in architecture. My father died during the second year of his degree, and then he graduated just after the financial crash. Getting a placement, let alone a job, was impossible.
The illness prevailed and I was at a loss as to how to help my brother battle the spies, evil Nazis and drug cartels that were after him. His experience was a bit like an action film, but without the fun bits and happy ending.
My younger brother always rejects the label of schizophrenia and I don't blame him.
Dr Emmanuelle Peters is an expert in psychosis at Kings College. "The term 'schizophrenia' can be stigmatising and scientifically it's not that meaningful, as there is so much overlap between different illnesses," she says. "However, for some people, especially carers, having a diagnosis can be helpful, as it means you know what you're dealing with."
My younger brother prefers to say that he has experienced psychosis – it frees him from a lifelong and unnecessary label.
In June 2012, my younger brother was sectioned for the fourth time. It felt as though we were trapped in a cycle that would never end. A yearly breakdown into psychosis, punctuated with periods of normality (whatever normal is). I decided it was time to stop hiding this part of my life and use what I had learnt to try to help other people. I don't have any useful skills such as nursing or teaching, so making a film was my only option.
The film tells the story of a girl who is trying to rescue her brothers from mental illness. I worked with the artist Graham Carter; animation studio Ticktock Robot and Oscar-nominated actress Samantha Morton.
I hope the film will communicate the importance of the role of a sibling and help destigmatise the illness.
More than 75 per cent of people who experience psychosis go on to recover completely, or the illness is episodic, but controllable. There is hope – both my brothers are doing well now, after years of the illness. I believe my mother played a big role in their recovery. She is a social worker who specialises in mental health.
She's an advocate of CBT and we often joke that she talked them back to health. The scientific evidence for the effectiveness of CBT has grown, but in spite of this research, the availability for patients is still low. This needs to change.
The strange creatures have left us in peace for now. I suddenly feel very nervous about people reading this and knowing my secret.
However, I am comforted by the fact that my brothers support me in writing about our experiences. If it can help just one person realise that they are not alone in their battle, then that has to be a good thing.
'Angels and Ghosts' is funded by the Wellcome Trust and screens at the ICA on Wednesday 15 January, as part of the London Short Film Festival. A trailer can be seen here: www.angelsandghosts.co.uk