A teenager chopped off his own penis and almost killed his mother when he was high on skunk.

The 16-year-old boy from Brighton had gone to bed with a knife because he feared that people lived in his walls.

He woke up in the middle of the night and stabbed his mother before cutting his genitals in a psychotic episode brought on by the high-strength cannabis.

A teenager chopped his own penis off and almost killed his mother when he was high on skunk (stock image)

His father named only as Nick spoke about the incident to raise awareness of the dangers of skunk on BBC 5 Live.

He told Emma Barnett that his son had been a 'bright, witty, rugby-playing lad' before he started taking drugs aged 16.

'He became paranoid. He switched from a very bright, bubbly lad to what I can only describe as a waste of space,' said Nick.

'He started out on normal cannabis but was switched to this skunk product. He used to store it for dealers and that's how it was introduced.'

His son has since told him that after trying skunk, he found that normal cannabis had 'no impact whatsoever'.

'He became delusional. He used to sleep with a tennis racket in his bed because he thought people were living in the wall. I remember one instance when he was telling us all that mermaids exist.

'At one point he was sleeping in the garden shed because he'd been thrown out of the house, and it was very difficult to have any relationship with him.'

On the night of the incident, he woke up 'ranting and raving' and attacked his mother at her home before turning the knife on himself.

The 16-year-old boy from Brighton had gone to be bed with a knife because he feared that people lived in his walls (stock image)

The young man's mother has made a full recovery. She and his father are divorced.

Nick added: 'It was absolutely devastating. You can't imagine anything of that nature happening. The whole episode was surreal. Looking back, it's almost as if I was peering in through a window and it's happening to someone else.'

He said his son has no memory of the incident, and has spent time in prison and in a psychiatric unit.

He has had several operations to reattach his penis, which have been successful, but he will need further surgery.

'Medical science moves on a great deal. He'll be seeing a very top specialist in that particular area.'

'He's drug free and alcohol free. He's actually in really good form. He's got his wit back. He's the first to have a bit of black comedy as far as this is concerned. I feel like I've got my son back.'

Lord Monson, who spoke to BBC 5 live about his own son's suicide in February, says he has been encouraged by a letter he received from the Prime Minister.

He says it is the first time anyone in government has drawn a distinction between cannabis and skunk.

In April, research released by York University showed that the risk of developing psychosis from cannabis use is small compared to the number of total users (stock image)

He wants to use his own experience to make educational films to be shown to teenagers, but is frustrated that government drugs advisors have warned some educational campaigns don't work and could even be counter-productive.

In April, research released by York University showed that the risk of developing psychosis from cannabis use is small compared to the number of total users.

Researchers said there is still a shortage of evidence from high-potency health.

Harry Shapiro, director of the charity Drug Wise, said that although psychosis cases like this are very rare, there has been a rise in the number of young people seeking help for cannabis use more generally.

He added: 'The danger of cannabis with a high THC content is that anyone thinking they may have an existing emotional problem, or a history of mental disturbance should stay away.

'People can self-refer to their local drug treatment service - or go to the 'FRANK' website and look for a local treatment service in their area.'