Dr Merryl Vorster commented on all aspects of the athlete's mental health; from the impact of having his lower legs amputated at the age of 11 months, his mother dying when he was 14, to his state at the time of shooting Reeva.
According to her analysis, Vorster believes Pistorius suffered from anxiety from a young age, and for this reason he often becomes paranoid about individuals or threats.
She added that Pistorius felt he was at higher risk of attack because he was a public figure, and this further compounded his anxiety.
For this reason, he was what she called 'hyper vigilant' and always in fear for his own safety.
Talking of the night Reeva Steenkamp was shot dead, Vorster added: 'Having a generalised anxiety disorder could have affected his decisions at the time if he was afraid.'
The Dr explained how Pistorius's amputation at an early age, coupled with his mother's early death, left Oscar as a 'distrusting and guarded' person who struggled to open up to people.
It was also heard in court how the athlete's mother slept with a gun under her pillow, and was a very anxious person who would often call Police to the house - worried about intruders.
However the prosecution are unconvinced about Pistorius's anxiety levels, and called today for the athlete to undergo a mental examination. If this is approved by the judge he will have to spend up to a month in a facility to undergo the examination.