With hindsight, dosing my brain and liver with huge slugs of brandy or lighter fluid wasn't the best way to deal with what I believed to be the onset of schizophrenia. But I had read that people suffering from psychotic illnesses tended to self-medicate, and anyway I was scared. Days spent in the pub - and later, as money became scarcer, the park - made me less scared.

The catalyst had been a panic attack one Sunday night two years earlier. Panic attacks were far less talked about back then, so I had no idea what was going on. Actually, that's a lie: I had one idea about what was going on and that was I Am Going Mad. This one idea went mantra-like around my brain in the days after my first attack, so, perhaps predictably, I had my second, third and fourth attacks within a week of the first, which only reinforced the idea. Soon I found myself in a vicious circle.

Brief respite came from an unlikely source. Reading a discarded tabloid on the bus one evening, I came across a letter sent in to the medical expert, describing exactly the symptoms I had experienced: shortness of breath, palpitations, a feeling of losing control and losing my mind. I read the expert's reply with relief: these feelings were quite possibly the result of a panic attack. They were harmless, common, could be treated easily and were not a sign of mental illness. This person was not to worry. I was not to worry.

I should have left it there, but I wanted to know more, so I turned to the family health encyclopedia. Again, I was comforted to read that these things were harmless and treatable, but then I came across the words that were to change my life for the next two years: "Less often [panic attacks] are part of schizophrenia."

I flipped to schizophrenia. "Can begin insidiously," I read. "Likely to occur in late teens or early 20s ... individual becomes more withdrawn, loses motivation ... outlook poor ... relapse, neglect, vagrancy, prison."

Had I been more withdrawn? What of the brighter colours and distorted appearance of people when I was in the throes of a panic attack; could these be the "visual distortions" mentioned? Of course they could.

Over an afternoon spent with the medical encyclopedia, I managed to convince myself I was suffering from schizophrenia. Now at least I had a new mantra: I Am Going Mad became I Am Schizophrenic.

Within a few months I had pretty much covered all the symptoms I'd read about: everything became drenched in meaning, I felt tingling sensations on my body, objects appeared larger or smaller than they were. Until I started hearing voices, though, there was still some hope.

This hope evaporated when, one grim night, I heard a voice in my head, whispering vague gibberish. Brandy shut it up for a while, but soon it became two voices (such third-person hallucination occurs "exclusively" in schizophrenia, apparently). I had the impression they were the two puppets on the balcony in the Muppet Show. Steadily they became nastier, less vague and more critical of my behaviour. Finally I found myself in A&E at five o'clock one morning and shortly after full of chlorpromazine (typically used for schizophrenia). I admitted myself to a psychiatric hospital.

Within hours I had checked myself out. Perhaps it was the relief of being able to share what had been going on without being labelled insane, perhaps it was seeing the far more serious condition of most of the people on my ward, or perhaps I was reacting particularly well to the pills that punctuated my days, but whatever the reason, I began to feel well. After a few months, I felt good enough to come off the medication.

Various diagnoses had been bandied about - depression, bipolar disorder, prolonged psychotic episode - but none stuck. I still don't know what was wrong, but my favourite self-diagnosis is medical student syndrome: acute hypochondria affecting medical students or readers of health books. Basically, I tricked myself into having schizophrenia after reading about it. And telling myself hundreds of times a day I was going mad didn't help.

Now, 10 years later, I am much better. I still have the occasional panic attack, but I have a new mantra now: I Am In Control. It seems to be working - except when I am doing too much and not sleeping enough. That's when the two Muppets on the balcony come back.