SINGAPORE - The personal psychiatrist of an elderly female Ferrari driver who punched a fellow motorist has argued that sending her to jail would be disastrous because she suffers from depression.

On Feb 25, 2014 Shi Ka Yee, 72, got into an argument with Raphael Chong Yen Ping, 39, in Telok Ayer Street at 5pm before punching him in the face. He was left with a cut above his right eyebrow.

She was found guilty on Aug 17 last year after a two-day trial but has yet to be sentenced.

On Wednesday (Feb 21), a hearing was held to determine whether Shi has an underlying psychiatric problem, and if there was a causal link between the condition and the offence she committed.

Shi was diagnosed with depression in 2009, Dr Pauline Sim Li Ping, a consultant psychiatrist at the Mount Elizabeth Medical Centre, testified. Dr Sim is Shi's personal psychiatrist.

Dr Sim said: "She was very disappointed to find out that her husband had an affair with a China woman. She felt very disappointed and taken advantage of."

During examination by Shi's lawyer, Mr Irving Choh, Dr Sim said that people with depression tend to react to provocation without thinking of the consequences. She said this could have been the case with Shi.

Dr Sim told District Judge Chay Yuen Fatt that those with depression might react on reflex and added: "Madam Shi often thinks that she was taken advantage of as she's a woman...She was shocked that a BMW driver (Mr Chong) would be rude to her...that's why she reacted. It would be disastrous to incarcerate her...treatment would be better."

During cross-examination, Deputy Public Prosecutor Zhuo Wenzhao pointed out that Shi had been attending regular yoga classes from 2011 and had also taken up a new hobby - dancing.

It did not fit in with the nine symptoms of depression as stated in the Diagnostic and Statistical Manual of Mental Disorders document, which is widely used by psychiatrists, DPP Zhuo said.

The symptoms include fatigue, recurrent thoughts of suicide, insomnia and diminished interest or pleasure. DPP Zhuo said that for somebody to be diagnosed with depression, he or she must display five or more of these symptoms.

Dr Sim testified that while Shi did not display six of the nine symptoms, the manual was only a guideline.

During the trial last year, the court heard that Mr Chong was parked in Telok Ayer Street when Shi sounded her horn because she felt he was blocking the way.

Mr Chong refused to move after she approached him and added: "If you don't know how to drive a Ferrari, don't drive a Ferrari."

That was when Shi got out of her red Ferrari. She took pictures of Mr Chong's car and then punched him.

Offenders convicted of assault can be jailed for up to two years and fined up to $5,000.

The hearing will resume on Thursday.