Dr. Lisa Ramshaw also told a sentencing hearing that Chiheb Esseghaier's delusional thoughts have developed over time, including his psychotic beliefs about the trial and his role in the court.
"He has indicated that he is not actually here as a criminal but as a visitor of the court to disseminate the information about the true ways of Islam."
Esseghaier took exception to the doctor's testimony.
"Mr. Esseghaier, I just noticed you're lying down in the prisoners dock," Justice Michael Code said during Ramshaw's testimony.
Esseghaier got increasingly angry and stood up.
"She is lying," he said, adding that he was lying down because he didn't want to "listen to the lies of this woman" which he said were about a "fake website" that she showed him during the assessment.
"You're not present if you're lying down and sleeping. That is not presence in Canadian law," Code replied before having him removed.
Ramshaw, who spent 15 hours interviewing Esseghaier, said it is her opinion that he is unable to participate in the proceedings at this time because he cannot fully understand what is going on in the courtroom.
She recommended anti-psychotic medication.
"His cognition appears to have changed over time," Ramshaw said.
"He gets very stuck on certain topics and cannot very easily leave those topics."
Code said if he decides that Esseghaier is unfit to represent himself during sentencing then he will have to re-examine Esseghaier's overall fitness.
Code ordered the psychiatric assessment in May after Esseghaier told the court he had been created by God to "warn mankind" about "hellfire" if the messages of the Qur'an weren't followed.
Esseghaier and his co-accused Raed Jaser were found guilty in March of a terror-related conspiracy to commit murder, which carries a sentence of up to life in prison.
A 12-member jury also found the men guilty of six other terror-related charges between them.
Earlier in the day, Crown attorney Croft Michaelson challenged the credibility of a psychologist who testified that Jaser was motivated by a severe drug addiction, not Islamic ideology.
Dr. Jess Ghannam, a licensed psychologist and clinical professor of psychiatry at the University of California, San Francisco, testified Monday that Jaser adopted a persona as a pious Muslim to con members of that community to feed his addiction.
Ghannam, who conducted an assessment of Jaser, concluded that the permanent resident of Palestinian descent did not have consistent radical Islamic ideology and had no intention to hurt anyone.
Michaelson questioned Ghannam's objectivity in the case, accusing him of massaging facts because they did not fit the theory he was trying to put forward.
He also accused Ghannam of disregarding diagnostic tests that showed Jaser had a low level of psychological distress.
Ghannam countered that the diagnostic tests were "one aspect" of his assessment.
"Probably the most compelling aspect of that was the clinical interview," he said.
During Jaser and Esseghaier's trial, court heard that an undercover FBI agent gained the men's trust and surreptitiously recorded their conversations, which made up the bulk of the evidence in the case.
The two were recorded speaking about alleged terror plots they would conduct in retaliation for Canada's military actions in Muslim countries, including the derailment of a Via Rail train travelling between New York and Toronto.
In one of the recordings, Jaser was heard saying "everyone is a target" and that he wanted "the whole country to burn."
Esseghaier refused to participate in his trial because he wanted to be judged under the rules of the Qur'an.
Jaser's defence lawyer argued his client was only faking interest in a terror plot as part of an elaborate con to extract money from Esseghaier and the undercover agent.