A 19-year-old man, whose upbringing was described by a judge as one of the worst he had seen, has been sentenced to seven-and-a-half years' jail for the attempted murder of his mother in 2018.

Key points: The Rockhampton court heard the man, who was 17 at the time, had been given drugs by his mother as an early birthday present

The Rockhampton court heard the man, who was 17 at the time, had been given drugs by his mother as an early birthday present The trial judge said the defendant was "in the grips" of drug use during events leading up to the crime

The trial judge said the defendant was "in the grips" of drug use during events leading up to the crime The man will be eligible for parole in February 2021, taking into account time already served

The man, who cannot be named for legal reasons, pleaded guilty in the Rockhampton Supreme Court to one count of attempted murder.

The court heard the man, who was 17 at the time, had been given methylamphetamine and cannabis by his mother as an early birthday present.

He later repeatedly stabbed her and threw her against a wall, fracturing her skull. She was hospitalised with life-threatening injuries.

Given drugs from age 12

In sentencing, Justice Graeme Crow told the court the defendant's crime was truly terrible and tragic.

He said the man endured an unstable childhood, with his mother "selling drugs for as long as you can remember", and that he and his siblings had moved in and out of the child safety system.

"In one instance of neglect, you and the other children were left alone for periods of up to two weeks at a time without providing food," Justice Crow said.

"You were sexually assaulted by a male as a child, and after that you went into foster care.

"All of your life your mum has been involved with illicit drugs; you first had involvement with cannabis at age 12.

"By age 14 you first tried methylamphetamine; your mother had been using for some time and you obtained the crystal methylamphetamine from your mother or her associates."

Justice Crow spoke of the defendant's mental health, outlining medical assessments that showed he had been suffering from substance-induced psychotic disorder since age 16.

"Symptoms include religious delusions, ability to read other people's minds, grandiose delusions," he said.

"The doctor concludes that this substance intoxication significantly contributed to the offence."

Meth was an early birthday gift

Justice Crow said the defendant was "in the grips" of drug use during events leading up to the crime.

"On the day of your offence ... your mother decided she was going to spoil you with a birthday present," he said.

"On that day you woke at your mother's house ... your mother was out of the house obtaining more methylamphetamine.

"She'd left, as you perceive it, a gift of a pipe of crystal meth beside your bed, which you accepted as part of your birthday.

"The day continued with the use of drugs, again sourced from your mother."

The woman's injuries included a fractured skull and 16 lacerations across her body.

Medical reports showed that if left untreated, she could have died, the court heard.

"You struck your mother on multiple occasions, inflicted wounds up to 10 centimetres deep — it was an act of extreme violence," Justice Crow said, adding the man had believed his mother was planning to kill him.

"You thought you needed to kill her, you were feeling paranoid ... and made comments about someone being an undercover agent. You were scared and paranoid."

'You never had a chance'

Justice Crow said the man's upbringing was one of the worst he had seen.

"Many would say you never had a chance.

"The outstanding feature in the present case is what you have done since you've been removed from your mother and placed into custody.

"You've done everything possible you can do to rehabilitate yourself — all sorts of courses, drug courses, first-aid courses, hospitality courses — and you're performing very well, as your teachers attest."

But Justice Crow said he had to consider the extremely violent nature of the offence.

"The fact you used the weapon, the knife inflicted those terrible injuries ... the fact you smashed your mother's skull.

"You are doing well because of your structured environment; if you are released, you are at significant risk of relapsing to illicit drug use.

"If you do, there's a very high risk your psychosis will return and place the community at risk."

The man will be eligible for parole in February 2021, taking into account time already served.