A man who was shot at a dozen times as he drove through a security checkpoint at RAF Mildenhall is believed to have been suffering from paranoid schizophrenia, according to a forensic psychiatrist.

Forty-eight-year-old Glenn Wardle had been experiencing delusions, including ones focused on former president Barack Obama, for months before trying to drive his Volvo up the ramp of a US Airforce Osprey helicopter, Ipswich Crown Court heard.

On December 18, 2017, Mr Wardle drove through gates, swerved around a pop-up barricade and even drove through four armed guards who shot at his vehicle 12 times - one of which tried to grab the car keys and was dragged along the ground for 30 metres before being forced to let go.

He also had a teddy bear strapped to his chest, a family heirloom called Charlie, who had its head torn off as soldiers checked for explosives.

The court heard that Wardle, who was prescribed anti-psychotic medication at the time, had a vision that morning of talking to Mr Obama after seeing a plane in the sky and believing he was on it.

Earlier in the year, Wardle had visited America to visit the CIA headquarters to ask them for a job, believing research into crystal skulls would help reveal the secret of eternal life.

He also visited former president Obama's home, wanting to ask him about the eye above the pyramid on the American one dollar bill and about the energy crisis the world is facing.

He was then arrested by the secret services, who also offered him an anti-psychotic injection which he rejected.

The service also passed details of the incident onto a mental health team in the UK, where he received some treatment.

Dr Toral Thomas, a consultant forensic psychiatrist, treated Wardle from only a few days after the incident for a year-long period.

When he first met Wardle he said he was "totally chaotic" and "in the grip" of his psychosis.

Wardle, of Ethel Colman Way, Thetford, has denied affray at RAF Mildenhall on December 18, 2017.

Before driving into RAF Mildenhall he said he may have mistakenly smoked spice instead of cannabis, through unintentionally mixing the two substances in a zip lock bag.

Dr Thomas stated it was extremely hard to test for spice, but that Wardle's results did test positive for cannabis.

The number of consistencies throughout his delusions over a prolonged period of time, September through to December, led Dr Thomas to diagnose him with paranoid schizophrenia and attribute that as the main cause of Wardle's actions and not drugs.

The court heard that when someone experiences a drug-induced psychotic episode their delusions won't reoccur over a prolonged period of time in the same fashion as someone who has paranoid schizophrenia.

Wardle demonstrated a focus on Barack Obama for months.

With regards to treatment, it took about two months for Dr Thomas to see a recovery which again aligns with paranoid schizophrenia, compared to psychosis caused by drugs which can be treated in a week.

The forensic psychiatrist acknowledged the two are linked, and that taking spice would have exacerbated the situation but concluded that Wardle had likely been suffering from paranoid schizophrenia from at least September that year.

He said: "Once you get psychosis it tends to get worse and worse and worse."

His previous episode in 2016, which saw him Tasered outside The Forum in Norwich, was attributed to drugs by the doctor due to how quickly he recovered.

The trial continues.