Pretoria — Murder-accused Oscar Pistorius has a general anxiety disorder which could affect the way he responds in stressful situations, the High Court in Pretoria heard on Monday.
"What makes Mr Pistorius different [from] other offenders is that he has a physical disability and general anxiety disorder, so his reaction to events would be different," forensic psychiatrist Dr Merryll Vorster said.
"If placed in an environment where you are not safe, your anxiety would increase. Mr Pistorius heard an intruder, so he had escalating levels of anxiety."
Prosecutor Gerrie Nel questioned Vorster whether Pistorius's general anxiety disorder could be seen as a mental disability.
She said that would be for the court to decide.
Nel asked if Pistorius could distinguish between right and wrong and whether his capacity to make the right decisions was diminished at the time.
Vorster said the court would have to consider the factors.
However, Nel said that if Pistorius suffered from diminished responsibility at the time of the shooting, then he should be admitted for evaluation.
Nel asked for a brief adjournment to study Vorster's report and the Criminal Procedure Act.
Pistorius is charged with murdering his girlfriend Reeva Steenkamp. He shot her dead through the locked door of his toilet in his Pretoria home on February 14 last year.
Pistorius has denied guilt, saying he thought she was an intruder about to open the door and attack him. The State contends he shot her during an argument.
Earlier, Vorster told the court the paralympic athlete's disability made him vulnerable and anxious.
"His physical vulnerability makes him more anxious. His vulnerability makes him want to conceal his physical disability," she said.
"His reaction to perceived threats should be considered in his physical disability," she said.
Speaking about the evaluation of Pistorius's emotions after the death of Steenkamp, Vorster said it was real.
"He is certainly remorseful about the events and feels guilty that he caused Miss Steenkamp's death," she said.
Vorster said he was distressed and the crying and retching were real.
"He was devastated that he killed his girlfriend. The emotions I saw, in my opinion, they were genuine," she said.
"What Mr Pistorius showed, he showed pallor, sweated profusely, and became pale. That is why his distress was genuine."
Pistorius is also charged with three contraventions of the Firearms Control Act -- one of illegal possession of ammunition and two of discharging a firearm in public.
He has pleaded not guilty to these charges as well.
The trial will resume at 1.30pm.