updated 10:34 p.m. ET Aug. 28, 2008

SANTA ANA, Calif. - An attorney for former mixed martial arts champion Quinton “Rampage” Jackson said Thursday her client was delusional when he led police on a chase and struck several cars last month.

Jackson, a light heavyweight, pleaded not guilty Thursday to felony counts of evading a peace officer, evading a peace officer against traffic and misdemeanor hit-and-run and reckless driving. He is free on $25,000 bail.

Attorney Carol Lavacot said the 30-year-old fighter was betrayed by a close friend and hadn’t slept for three days before the July 15 incident. Lavacot would only say that the betrayal was about finances.

During the episode, Lavacot said, Jackson believed if he fell asleep he would die and kept himself awake with energy drinks. She said he also believed that he had to get to another friend’s house to save him from dying and was on his way there when he hit several cars and police began chasing him.

“For those people that know Quinton, they know that he’s a very kind, gentle giving person and he feels so badly about his actions,” she said in a telephone interview.

“He takes complete full responsibility for what happened, but he was delusional during that ride down to his friend’s house and really believed that it was a matter of life or death.”

After his arrest, Jackson spent five days in the hospital for mental evaluation, she said.

Lavacot said psychiatrists who treated him found that he suffered a “brief reactive psychosis” brought on by stress, dehydration and exhaustion but that he recovered quickly and has very limited memories of the chase.

Jackson lost his Ultimate Fighting Championship title July 5 to Forrest Griffin.

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UFC spokeswoman Jennifer Wenk referred calls to authorities.

Deputy District Attorney Keith Bogardus had no comment on Jackson’s mental health or the evaluation at the hearing Thursday.