Image copyright Sally Wilson

Mother's Day is approaching but as any mother knows, stepping in to the role can be a turbulent time. For some it can be devastating. As many as one in 500 are thought to suffer from post-partum psychosis. University lecturer Sally Wilson was one of them.

The photo shown above is of me, my husband Jamie and our two-year-old daughter, Ella, taken on a skiing break in France a few weeks ago.

It looks no different to any other happy family holiday snap does it?

But the events leading up to it, the beginning of our family life, is wildly different to that of other new parents.

It is a story of ruin, of living the most terrifying, inescapable nightmare day after day, of being in such utter pain and despair that I constantly thought of walking into the sea near our home in north Wales.

Before giving birth to Ella I was totally unaware of a condition called post-partum psychosis (PP).

Image copyright Sally Wilson Image caption Newlyweds Sally and Jamie, huge sports enthusiasts who met at university, walk under an arch of climbing axes and hockey sticks

Two years on, I have virtually fully recovered. It's not been easy and involved some controversial treatment.

But the day I thought would never come is here; when I enjoy the familiarity of the old me.

In 2013, Jamie and I got married and, as planned, started a family a year-or-so later.

My pregnancy was good. I was a week overdue and had some signs of pre-eclampsia, a condition in late pregnancy which can be dangerous if not treated, so I was induced.

Image copyright Sally Wilson Image caption Five months pregnant: Sally with Jamie, who also works as an academic, in Greece

My labour was painful, no shock there. But as the hours went by, things began to deteriorate. I became terribly confused. I had difficulty grasping the notion of time. I barely slept and felt feverish.

The medics ramped up hormones for induction and I was given gas and air and pethidine. Ella's heart rate kept dropping and she was in distress.

She was born early in the morning in March 2015 by Caesarean section.

As I came round from the anaesthetic, something very sinister was unfolding.

My confusion was by now off the scale. I kept saying I didn't understand what was going on, asking why there were doctors in the room.

A brain scan for a suspected stroke and blood tests came back negative.

Image copyright Sally Wilson Image caption A new-born Ella who was initially being treated in special care for breathing difficulties

At one point I remember my eyes rolling back in my head and I slumped onto the bed.

At night I pleaded with the nurses to sit with me as I was so scared. I was also paranoid that the midwives were talking about me.

By now I was very panicky, convinced I was doing something wrong and would get upset.

A few days later things got a lot worse. I got up to go to the toilet and collapsed. I was sobbing and refused to get up.

In my mind there was a strange realisation that I'd died. I could see everyone around me, the midwives and Jamie behind me. I saw a midwife take Ella away, I believed they were taking her to be resuscitated because I'd harmed her.

Media playback is unsupported on your device Media caption Sally Wilson explains her experience of suffering from postpartum psychosis

I now know that I was having a psychotic episode. My reality had shifted, I believed I had died and was living in an afterlife. I began to hallucinate.

The sound of babies crying was deafening, the whirr of air conditioning unit overwhelmed me and the canteen trolleys sounded like trains crashing through the ward; lights being switched were like explosions and I could see shadows on the wall.

I was convinced that because I'd hurt my baby I had died and was now living in the 'after life', a kind of hell.

The most terrifying nightmare imaginable was now my reality.

The nurses brought Ella to see me, to reassure me she was ok. I was convinced they'd swapped her.

This wasn't my baby. My baby was dead. I had killed her.

Find out more

Links to organisations offering support on PP below or visit BBC Action Line

For help and information on mental health visit BBC Advice

"What's wrong with Jamie? Why's he crying?" He's not crying Sally, look he's fine. "Who are those people outside the door in white coats?" There's no one outside the door Sally. "Yes, there are. They've come to get me and take me to prison. Oh God… how could I have harmed my baby?"

It was horrific.

I was transferred to the psychiatric ward and Jamie was told I was suffering from PP. I was prescribed anti-psychotic and anti-anxiety medication.

All I can recall is being led into a terrifying maze where I'd see people pacing around as grotesquely exaggerated caricatures.

I would refuse to have bloods taken, convinced there was a conspiracy against me.

Jamie and my parents would visit with Ella and I'd hold her but couldn't understand that she was mine. I felt no connection.

We went to the café and she needed her nappy changed. The toilets were near to the labour ward and I became really stressed out and upset as I didn't want to go anywhere near there. I thought I couldn't be trusted on the labour ward as I was convinced I'd hurt my own baby.

Image copyright Sally Wilson Image caption A month-old Ella's first experience of the Snowdonia National Park

A week later I had a review with the consultant and I told him things were better than they were just to be allowed out of there.

A home treatment team was arranged to visit me every day but things didn't improve much. I'd manage to help meet Ella's basic needs, change and feed her. But I was going through the motions.

I still 100% believed that I'd killed my baby.

I hit an extreme low, a bleak depression punctuated with psychotic symptoms.

I'd read a news article about a murder at a caravan park which had happened on the day I had the psychotic episode in hospital. In my mind I'd committed the murder.

The sound of birds was really loud, particularly crows. I then discovered the collective noun for crows is 'murder' - I interpreted meaning to that, of what I'd done in the hospital.

Image copyright Sally Wilson Image caption Sally on holiday a few months after embarking on ECT and around the time she began to feel better

I had an obsession with a certain number bus which always seemed to pass when I left the house. This was part of the conspiracy and had a hidden meaning.

Over-powering, intrusive images constantly flashed into my mind, of walking out into the sea near our home and ending it all.

Ten months after coming home, I told Jamie that I couldn't go on. My husband, who'd done so much to help me, was distraught.

Determined to help, Jamie did a literature review on PP treatments. Electro-convulsive therapy (ECT) came up a lot.

My psychiatrist contacted Ian Jones, Professor of psychiatry at Cardiff University, National Centre for Mental Health director and a world expert in PP. He agreed that ECT might help me.

You immediately think it's a barbaric, horrible treatment, involving being strapped to a chair and electrocuted.

It's fairly dramatic - you're anaesthetised and electrical currents are passed through your brain to trigger a seizure.

Image copyright Sally Wilson

Half way through the 10 sessions, there was a shift in my thinking. Something terrible was being lifted from me. It saved my life.

Gradually I've grown stronger and bonded with Ella.

It's sad to think about what I've missed out on but now I look at her and get excited that everything's ok, we're here, happy and healthy.

I can't say I'm the same person. But I'm back at work a few days a week and I'm pre-occupied with the everyday challenges of parenting.

Once you've suffered from PP there's a very high chance of it recurring with subsequent pregnancies. It's a very personal choice, but even if there was only a slight risk of going through that again, for us, it's just not worth it.

But it's very important to me to give hope to others going through the horrors of PP. You'll be convinced it will never, ever end. I was convinced too. But this is a day I thought would never come when life feels good once again.

Image copyright Sally Wilson

The facts on PP

What exactly is it?

Of wide spectrum of post-natal mental health problems, PP is one of the most severe. Post-natal depression affects something like one in 10 women, and PP one in 500 to 1000. Includes psychotic symptoms, believing things that are not true and prominent mood symptoms - both high and low

How does it manifest?

PP can come on quickly, out of the blue. Within hours women can go from perfectly well to as ill as we see people needing psychiatric care. In others, it might not be so rapid or obvious

Who is vulnerable?

For around 50% PP is the first episode of mental illness they've had. The other 50% will have had previous psychiatric illnesses. Bi-polar disorder are at particularly high risk, a 20% (1 in 5) chance. Extremely high risk are those with previous PP episodes with a 50-60% chance of reoccurrence

What causes it?

There are many hypotheses - big hormonal changes, sleep disruption or immunological changes. An important role, and an aspect of our ongoing research, are genetic factors.

Prof Ian Jones, Cardiff University

As told to Ceri Jackson