“I don’t know whether or not I’ve had a bad trip.”

Someone said that to me once in a conversation about psychedelics. My response was laughter.

“Trust me,” I said. “If you’d had a bad trip, you would know it.” I’ve had a bad experience on LSD, and it was the most terrifying, harrowing thing I’ve ever been through. I share the following as a cautionary tale to anyone who uses, or is considering using, psychedelics.

The precise circumstances in which I took the drug don’t matter. Suffice to say that I was far from home in an unfamiliar (and public) environment with people I didn’t know very well and had little reason to trust. In other words, it was as unsuitable an environment for psychedelic experimentation as I could have designed, but hey, I was 23, had nothing better to do, and had taken both LSD and psilocybin before (once each) without disaster, so I thought I knew what I was getting myself into. If only.

I’d been warned the tabs were strong, but I shrugged it off and put one under my tongue. What was the worst that could happen? The first effects arrived within fifteen minutes, which is abnormally fast; these tabs were strong indeed. My last clear memory is of returning to my room and clambering into bed.

Then I lost my mind.

Mark Manson wrote the following when recounting what he calls a bad acid trip: “You don’t necessarily see large things that are not there. You see what’s always been there in a multitude of new ways.” Oh Mark, you sweet summer child. If you think LSD doesn’t make you see things that aren’t there, I implore you to try a higher dose. Just be warned: it might expand your definition of “bad trip”.

As for me, I was lost in a vortex. The patterns swirled around me so intensely that it made no difference if my eyes were open or closed. I didn’t have eyes; I was a brain in a jar, a disembodied mind floating through space. I had no memories of my past, no sense of my own identity, no understanding that I had taken a drug. For a while it might have been pleasant.

Eventually - was it minutes, or decades? - a light flickered on somewhere in the hollowed-out recesses of my brain, and I started to question my surroundings. Where was I? Who was I? What was I? Panic set in as I realised I had no answers. Nothing made sense except terror.

What happened next defies description, but I’ll try. It was if my every mental faculty had burnt to a husk, leaving only the most basic emotions in their rawest forms. Confusion. Fear. Shame. I didn’t know my own name, but that’s understating it: I didn’t know what a name was. The basic facts of human existence were beyond my grasp, swirling around in shattered pieces at the edge of my awareness, fleeting glimpses that only raised further questions.

I hallucinated vividly, as real as any waking experience. I was walking down the street. No, I was sat at home. No, I was at the office, a regular workday, but my colleagues were giving me funny looks. Had I done something wrong? I became convinced there’d been some sort of horrible accident. I was in the back of an ambulance. I was in hospital. I saw blood, bodies, mangled wreckage. What had happened? Was I responsible? The panic gripped me tighter. I had fucked up. I had killed someone. I was going to jail for the rest of my life. I was an international news story. The eyes of the world were on me. My life was over. These are all thoughts I held as the C20H25N3O bound to my serotonin receptors, except they weren’t really ‘thoughts’. I had no inner monologue, no ability to form English sentences. All I knew was the purest sense of humiliation and shame.

It went on for a million years. That’s what it felt like: I stayed for an eternity in a dimension beyond time. You can’t understand if you haven’t been there. When I finally came to my senses, I couldn’t believe I was still in the same room where I’d started. It took some persuading - and some further sobering up - before I understood that only a few hours had gone by, during which all I’d done was writhe around in bed and cry for help.

You can imagine my relief to learn that I hadn’t, as I had genuinely believed, been criminally responsible for someone else’s death, but to say the experience shook me up would be like saying there are political tensions in Syria. For months afterwards I could think of nothing else. I didn’t have “flashbacks” (I’m not convinced these are a real phenomenon), but memories of scenes I’d seen while high kept intruding on my thoughts, jolting me awake with an echo of the fear I’d felt on the first playthrough. It was a long time before I felt fully back to normal.

I’m not here to play victim; no permanent damage was done, and there are worse traumas one could live through. All I want is for aspiring psychonauts to get a better idea of the risk they’re taking. LSD can go well (and I have stories about that too) but don’t underestimate its potential to go very, very badly. “Set and setting”, kids. It matters more than you know.

Supposedly the effects of LSD can be cancelled out by antipsychotic medication - that is, the same stuff they give to schizophrenics. Maybe a bad acid trip can be thought of as an acute case of chemically-induced schizophrenia. Whatever the case, I now have a visceral understanding of what it feels like to be insane. Thank God it wore off. I can’t imagine the suffering of someone trapped in that hellscape with no exit.

Some might say the moral is “don’t do drugs”, but I wouldn’t go that far. I’ve taken psychedelics again since that day with positive results and I’ll continue to enjoy them in moderation. In a sense I’m even grateful for the bad trip, horrifying though it was, because “what doesn’t kill me makes me stronger” and at the very least I learnt something. Psychedelics can certainly be a learning experience, but what will you learn? No way to know until you try for yourself. Just be very careful about when, where and how.