By Daily Mail Reporter
Last updated at 7:16 AM on 07th October 2008

A teacher's son murdered his girlfriend after being driven mad by ten years of smoking cannabis, a court has heard.

Marc Middlebrook had ignored repeated warnings to quit the drug when he stabbed Stephanie Barton 15 times with three knives as she lay naked in his bed.

Psychotic Middlebrook, 27, had become convinced she was part of a plot to kill him and said he 'wanted to put her out of her misery'.

He denies murder and has admitted manslaughter on the grounds of diminished responsibility, claiming he was suffering from mental health issues at the time.

Prosecutors say he made his problems worse by 'stubbornly' persisting in his use of cannabis - despite doctors advising him to stop.

William Harbage QC, prosecuting, told Lincoln Crown Court: 'If it was not cannabis we would not all be here. You will hear about his odd behaviour.
'It included the paranoid belief that his life was under threat by a group of people intent on killing him.

'We say the main cause of this odd behaviour is his long-standing abuse of cannabis smoking, which we say is entirely self-induced.'

The jury heard Middlebrook had smoked cannabis since the age of 16, increasing his use after meeting accountancy student Miss Barton,32.
He had cut down shortly before the killing but was nonetheless still smoking the drug 'right up to her death', the court was told.

Mr Harbage said the jury would hear evidence from experts about the way in which smoking cannabis could contribute to paranoia.

He said: 'The psychiatrists all agree cannabis, even if it does not directly cause paranoid psychosis, greatly aggravates a pre-existing condition.
'He had an abnormality of mind, but it was self-inflicted - in that it was caused or contributed to by his stubborn taking of cannabis.'

Miss Barton - known as Stevie - was found dead at Middlebrook's home in Boston, Lincolnshire, early on the morning of December 4 last year. Police forced their way in after being alerted by Middlebrook's mother when she received a text message from him.

The defence claim Middlebrook was schizophrenic.

His mother Denise told the court she was shocked to learn of his drug use. The former teacher said: 'I don't think he was a regular user - I think they call it a recreational user.

'I thought he had more sense than to use them.'

The trial continues.

__________________
*For Entertainment Purposes Only.* Remember, spread the love and hit the +rep button. And, check out www.kiva.org

Did you forget somthing. Did he cut down his plants? Is that what is was going to say?

__________________
OG KUSH
Bleezy's Grow Journal Bleezy's Vidoes Updates http://www.youtube.com/user/Bleezyg420

i claim insanity to if i killed someone. Hell isn't that the norm now.

you all better hope i never break these chains. muhwahahhahahha

__________________
i'm the guy i've always wanted to be

wow. idk if hes bullshitting, or just smart. but if he gets off, i think thats what ill start doing, offin people and claiming insanity cuz im a pot smoker HAHAHA

__________________
Dont worry,Im not gonna do what everyone thinks im gonna do and FLIP OUT MAN!..all i wanna know is whos comin with me?Everything I say and post are lies!!!! MyGrow!!!!

I"d like to smack him for sullying the names of pot smokers everywhere.

__________________
The rousing tale of a young gynecologist:
Now that I've made you laugh,Sign my petition.
http://www.petitiononline.com/420now/petition.html

Just give the kid life in a padded room and don't let me in there cause I'll give him a talking too . . .

__________________
A garden of gratitude must first be cultivated in a mans soul before any seed will grow for him.Hydro Q's
My Journal

It's called "Reefer Madness", a well-diagnosed clinical condition.

You all should watch this documentary that was made in 1936

Reefer Madness

The incidents and characters portrayed in this motion picture are purely fictional and any similarity to actual occurences and living or deceased persons is coincidental.

__________________
Grower's Bookshelf

Yeah I remember seeing that study before . . . very scientific.

__________________
A garden of gratitude must first be cultivated in a mans soul before any seed will grow for him.Hydro Q's
My Journal

This guy was predestin to be a nutjob long before he started smoking weed. If he were on steroids, they would try to blame it on them also . If not them , maybe he would blame his parents for not hugging him enough.