SYDNEY - Sydney siege gunman Man Haron Monis thought people could read his mind, the continuing inquest into the December drama he staged in Sydney has heard.

The inquest is examining a range of issues in relation to Monis, who took 18 people hostage at the Lindt Cafe in Sydney's Martin Place on Dec 15.

Cafe manager Tori Johnson, 34, and 38-year-old lawyer Katrina Dawson were killed, along with Monis when police raided the cafe.

Rebecca O'Brien, who was a mental health worker for the Canterbury Acute Care Team, said on Thursday she did a mental health assessment of Monis in April 2010.

O'Brien said Monis had been brought in by ambulance from a car park at shops where he was displaying "bizarre behavior."

Monis told her he had pain all over his body when he was stressed and it had been going on for five years.

He said he was often unable to use his arms and legs.

"He was quite guarded and reluctant to disclose too much information," she said.

He provided a post office box address and at first declined to give his home address but eventually revealed he lived nearby.

She said he thought people were watching him and was highly paranoid and delusional, but did not pose a threat to others despite thinking people could read his mind.

"He was a little bit controlling ... talking without listening, " said psychologist Kasim Abaie, who said he saw Monis three times in 2010.

"He was wearing sheik clothes."

Abaie said Monis told him he was "feeling stressed with a depressive mood".

"He was jumping from one topic to another topic," he said.