He ran out of his home stark naked after taking a new psychoactive substance called Spice, which almost killed him.
David (not his real name), 37, had been taking drugs since he was a teenager, but had managed to evade contact with the law until that near-death episode a few years ago, after which he decided to clean up his act.
After having smoked Spice for a few weeks, he began hallucinating, became paranoid and was afraid to even leave his house.
"I lost touch with reality, and I was hearing voices," David told The Straits Times. "I was hiding underneath my kitchen table and shivering. I thought my neighbours were checking up on me."
Once, he was taking a shower when he suddenly freaked out and ran out of his home naked.
A neighbour called the police, who were questioning David when he collapsed. Doctors found that his kidneys had failed and that he was near death. But he survived the episode.
He told ST he had been abusing Ice, or methamphetamine, and marijuana for years - those drugs had also made him hallucinate, but the effects were not as serious as the hallucinations brought on by Spice.
David, who was introduced to drugs by a schoolmate at a top secondary school, started experimenting with them when he was 16.
Despite his drug habit, he managed to earn a degree, and had a good job until the addiction unravelled his life. He was smoking up to 10 joints of marijuana a day and could think of nothing else.
Yet, he was never arrested on suspicion of drug use, even after having taken drugs for more than 15 years. He remained in denial of his addiction. Then, a few years ago, his drug dealer introduced him to Spice.
David, a professional, said: "My near-death experience was enough to shake me up to stop drugs.
"Don't start; you don't know what you are messing with."