By Zjan Shirinian

Oscar Pistorius has had an anxiety disorder since childhood, according to psychiatrist Merryll Vorster ©AFP/Getty ImagesAttempts to have Paralympic athlete Oscar Pistorius undergo a mental health assessment are "manifestly absurd", his defence team has argued at his murder trial.

Prosecutors today formally made the request, after psychiatrist Merryll Vorster said the 27-year-old has generalised anxiety disorder (GAD).

She told the Pretoria court Pistorius is a "distrusting and guarded" person who is "hyper-vigilant" about security.

Judge Thokozile Masipa will give a ruling on whether Pistorius should undergo the assessment - which could see him spend up to 30 days at a state hospital - tomorrow.

Pistorius is on trial accused of the premeditated murder of his 29-year-old girlfriend Reeva Steenkamp on February 14 last year in his Pretoria home.

He admits killing her, but says he thought there was an intruder in his home when he shot four bullets through a locked toilet door, three of which struck and killed the model and law graduate.

Arguing his case in court, Prosecutor Gerrie Nel said a "psychiatric evaluation was essential".

But Pistorius' defence team is strongly resisting such an assessment.

Reeva Steenkamp's mother June has spent another day listening to evidence and legal discussions at the trial of Oscar Pistorius ©Getty ImagesReeva Steenkamp's mother June has spent another day listening to evidence and legal discussions at the trial of Oscar Pistorius ©Getty Images

Spending a second day on the witness stand, psychiatrist Vorster explained the nature of GAD.

"It may impact on your capacity to live a normal lifestyle," she said.

"By definition generalised anxiety disorder is a psychiatric disorder, so one can say it's a mental illness.

"But one has to look at the impact of that diagnosis on the individual's capacity to live and socialise."

She added: "He had distress because of his anxiety disorder but he was at that stage, still able to continue with his life."

Vorster said yesterday the athlete has had an anxiety disorder since childhood and his actions on Valentine's Day last year "should be seen in context of his anxiety".

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