Content note: This article contains detailed discussion of mental health.

I was eighteen. It was a summer day like any other, and I was next to the stairs in my house, in Italy, when I suddenly had this one thought. The thought was spoken by an internal voice, and both thought and voice sounded alien.

It was like flicking a switch. The previous day I had been living my regular, teenage life. In one instant, it was gone. Suddenly the thought was all I could see. A series of flashes followed: they were graphic, repetitive, disturbing.

What was happening?

My brain felt on fire. I tried to focus on other things, but I couldn’t. The thought was echoing. The flashes were multiplying. Nothing was making sense. I panicked. The voice within me asked: what if this thought never leaves?

My descent into “pure-O” – a form of OCD characterised by primarily mental rituals – began on that day. I now know that my experience of OCD had started earlier, in primary school, with a sudden fear of the plague that had swept through fourteenth-century Europe, vividly described in my history textbook. Fear of the plague had quickly morphed into fear of HIV and contamination, and an associated range of overt compulsions I performed. All of that, however, had been left behind entering high school, and on that summer day it was only a childhood memory. It would take years before I would make the connection between those experiences.

I kept hoping one day I’d wake up and the thoughts would be gone

Intrusive thoughts are random, unwanted thoughts, experienced by almost everyone in the population. However, if you have OCD, intrusive thoughts are more noticeable, and “sticky.” When they enter your mind, they cause a surge of anxiety. To relieve the discomfort, you respond with an action, which is the compulsion. This makes you feel better temporarily, but in fact teaches your brain that the thought is important, and must be responded to. A vicious cycle between behaviour and thought is established: the intrusive thought becomes an obsession. Compulsions can be overt, like washing or checking, but often they are mental, involving analysis, neutralising behaviours, avoidance of triggers. This type of “invisible” OCD, which I developed as a young adult, is nicknamed “pure-O.” The themes of this form of OCD can be, and often are, very dark or embarrassing, often gravitating around sex, violence, religion, or relationships. Regardless of the theme, the thoughts are ego-dystonic, meaning that they do not align with a person’s character, values, desires or sense of self. The target of OCD is usually something that matters greatly. No matter the theme, people with OCD are not dangerous.

That “uneventful” July day became the day 0 of my new existence, and things very quickly spiralled from there. In the course of the years that followed, my OCD jumped from theme to theme, but it would present to me over and over questions of the following type:

What if, deep down, you are a psychopath?

What if you molest the person who’s sitting next to you right now?

What if you grab that knife and stab the friend you’re talking to?

These types of thoughts were incredibly shameful, and terrified me. They were too extreme, too wrong to be spoken out loud. How could I have these thoughts? And how could I tell anyone? What kind of person thinks these things? I feared people would believe the thoughts were real, would hate me, and ostracise me. So in front of everyone, I kept pretending things were fine. I became a great actor, and not many people ever noticed that something was off.

In my head, however, I would spend hours of every day debating what the thoughts meant. They never felt like a reflection of who I was. But if there was no truth in them, why would I think them? Whenever I seemed to reach a solution, another thought showed up, or the theme would abruptly switch, and I would have to start from square one. I wasted years of my life in that internal chatter. I believed that logic would enable me to understand and “solve” my thoughts, but I did not know that you can’t reason your way out of OCD. With every passing day, those thoughts, images, and inner conversations wreaked havoc on my sense of self.

I developed rituals I would perform mentally in a number of situations, like repeating actions with a neutral image or word in mind, that would “counter” the obsessional thought. I was also convinced that the intrusive thoughts presented a real danger, and therefore would act on my mind’s instructions to prevent whatever catastrophic outcome was threatened. For example, I would hide knives from sight for fear I would stab someone. I would avoid watching news or crime films which might give my mind ideas. I would avoid children because I was terrified I might harm them. The list goes on. As OCD got bigger, my world kept shrinking, until there was literally no space left. Unsurprisingly, with these obsessions, my self-esteem hit rock bottom.

The secret became a barrier between me and others, and I felt unable to connect with anyone on a deep level. The years passed, but it was as if time had stopped for me. While from the outside my life looked normal, I was spending most of my days in rumination, often from the moment I woke up to the moment I went to bed. Usually, the rumination would stop or lessen when I was busy with a task at hand, so I craved distraction.

I kept hoping one day I’d wake up and the thoughts would be gone. They had arrived in one day. Maybe just as suddenly they would go? Cyclically, my brain would undergo some quiet periods in which the obsessions disappeared or lessened, sometimes for so long I’d begin to believe they weren’t coming back. And every time, when the cycle restarted, my hopes grew dimmer.

I made choices in my life which were a direct consequence of OCD, like when, after graduating from my bachelor’s in Biology, I started a second bachelor’s in a different field, because during those first years at university the intrusive thoughts had been so terrible that I wanted to start over, throw those years away. Needless to say, changing subject did not cure my OCD.

When I was finishing my second bachelor’s, I finally landed on the Wikipedia article for “obsessive compulsive disorder.” I was in shock to read a list of thoughts and behaviours which I had believed were unique to me. It was an immense relief to find that there was an explanation, that I wasn’t bad, nor stupid, that those obsessions were not my fault, did not define me or reflect my character. I had believed what was going on in my head was something so complex and incomprehensible that no one else in the world could have experienced it, let alone articulated it – and there it was: what was going on in my head was a checklist on a Wikipedia page.

At that point, I realised there might be a way to get help. I walked into a therapist’s office and broke my seven-year long silence, revealing in tears much (although not all) of what was going on. I spelled out the words “obsessive compulsive disorder.” Although by that time my intrusive thoughts were so bad that I was not sleeping, and could barely leave the house, eat, speak or listen to a conversation, I was assured that it made no sense to pathologise “sad times”. What I had was an overactive imagination: no one can self-diagnose, and I did not have OCD.

Before diagnosis, it was as if I had drifted apart from the real world and had been silencing my emotional pain for over a decade

It took me five more years before I found the strength to approach a therapist again. After my second bachelor’s, I somehow managed to get better, and eventually came to the UK as a postgraduate student. The year of my master’s and my first year of PhD were great: a change of scene and a good social life were powerful antidotes to rituals and disconnection. OCD was manageable, and even, for months, gone. In my second year, however, the cycle began again and, by the beginning of my third year, it was spiralling. I asked for help, and, this time, was diagnosed straightaway.

I have now been in treatment for a year, and have come across some really nice people who have helped me, both at the university counselling service and in the NHS. I have read extensively about OCD. I attend a support group which I find very helpful. Thanks to what I have learnt, I have managed to cut down some compulsions altogether and have been better, although I am not yet recovered.

However, things have not been easy. Before diagnosis, it was as if I had drifted apart from the real world and had been silencing my emotional pain for over a decade. Opening up and being diagnosed felt like reconnecting, and reconnecting was painful: it was like waking up and suddenly seeing the wake of destruction behind. Grief, anger and sadness came in waves that felt too powerful to handle. The NHS waiting list for treatment was five-months long. Five months are endless when you are struggling with a mental illness and with those associated emotions, and during that time my disorder became very debilitating.

The therapist I was assigned after this waiting time seemed to know very little about OCD. My discussion of what I realised was then my current, main obsessional theme was dismissed as a “waste of time”. I was encouraged to work on my old, “classic” obsessions, however in ways that were often in complete contradiction with everything I had learnt about my disorder. Every attempt to raise these issues with my therapist was useless, and my request to speak with the university counselling service to discuss my current state and the problems with my NHS treatment was denied on the grounds that I was having NHS treatment. My frustrated reply, stating that I felt like no one was helping me, went unanswered.

(A spokesperson for the University said that there is not a  University Counselling Service policy to deny counselling if a student is already receiving NHS treatment. They also said that  "if a student is receiving treatment under the NHS we would usually wait until that treatment course is finished to assess where the best place for them to get support afterwards is.If someone is having problems with their NHS treatment, we would advise that they speak to their NHS provider, or their GP. It would be very difficult for us to give advice without a full and complete medical history".)

Eventually, I was assigned another therapist, and things got much better from there, but those were some dark and difficult months. It is hard to wait to receive help when asking for help has taken you years, and navigating the system is especially difficult when you are unwell.

The delay in my diagnosis is not an exception: according to the charity OCDAction, the average time between onset and treatment for OCD is 12 years. One reason is lack of awareness in the population, and even among some mental health professionals (as was the case for the therapist I saw in Italy). Another major problem is the stigma surrounding the themes of the intrusive thoughts. That stigma is real, and is preventing people from asking for help and getting better.

Messages that remind us to take care of our mental wellbeing, and ask for help if things get rough, are nice, but hardly helpful for someone like me. Awareness needs to be raised as to the specificity of the conditions, and their symptoms – in the case of OCD, the nature of obsessions. I did not ask for help for a long time because I thought other people had mental illnesses, but I, with the thoughts I was experiencing, was just a bad person.

But this is the first time I am writing a piece on OCD, and will not be the last

Even after diagnosis, stigma is massive because of the lack of awareness in the general population on the ways OCD manifests. I have heard a graduate student say that, because of the theme of their obsession, if they were open about their OCD they would lose their chances of an academic career. All it would take is someone raising the doubt – what if the thoughts are real?

In this article, I have only sketched some aspects of my experience with this condition over the years. My OCD has morphed repeatedly, and has affected me in more ways than I have been able to describe. But this is the first time I am writing a piece on OCD, and will not be the last.

OCD goes where it can hurt the most. It is a complex, paradoxical illness, and it can target anything: your values and your morals; your relationships; your sexuality; your gender identity; your religion; your health; your memories; existential questions; the things and the people that matter most to you; literally anything. It doesn’t matter what the thought is or how awful, or ashamed, or confused, or disconnected it makes us feel. There is treatment for OCD, and it should not take people years to get it.

• If you have been affected by any of the content of this article, the following provides support and resources: OCDAction – call 020 7253 5272 (open 9am to 5pm weekdays) or visit www.ocdaction.org.uk/; OCD-UK – call 03332 127890 or visit www.ocduk.org/.