A Santa Rosa man accused of stabbing his father to death in their Rincon Valley home was suffering a drug-induced psychosis from taking his mother's prescription pills but was not mentally insane, according to a doctor's report released Monday.

Houston Herczog, 21, was in the grip of Adderall, a psycho-stimulant prescribed for attention deficit hyperactivity disorder and narcolepsy that also has a following among recreational users and has been labeled a "study drug" for its ability to keep people awake.

Reported side effects of Adderall include mood swings and aggression. A number of websites discuss "Adderall rage," a condition of becoming infuriated while withdrawing from the addictive medication.

Menlo Park psychiatrist James Missett examined Herczog last week and found he had been taking the pills. His 34-page report concluded the drug played a role in the attack but said Herczog was fully aware of what he was doing.

Three previous psychologists found Herczog was suffering schizophrenia at the time. The 2009 Santa Rosa High School graduate has pleaded not guilty by reason of insanity. Family members have urged that he be placed in a mental hospital instead of prison.

His lawyer, Karen Silver, said Monday that Missett's findings are wrong.

"All it shows is that if you get enough doctors, you will find one to go the other way," Silver said.

The District Attorney's Office declined to comment because they said it was an open case.

Missett's report comes as both sides prepare for trial. Jury selection is expected to begin this week and witness testimony is next week.

Herczog is accused of killing Mark Herczog, 63, in their Parkhurst Drive home after returning from a late night trip to the gym.

His younger sister, Savannah Herczog, was awakened by a struggle and called police. They arrived to find the father had been stabbed more than 50 times.

Houston Herczog was arrested without incident and has remained in custody ever since. Last year, he was deemed mentally competent to stand trial after a two-day fitness hearing.

But family members said he suffered mental illness in the year leading up to the killing. His aunt, Annette Keys, testified he deteriorated after a car crash that left him with a concussion. Keys said his dad didn't call police because he feared officers could resort to violence if they confronted Houston Herczog.

You can reach Staff Writer Paul Payne at 568-312 or paul.payne@pressdemocrat.com

EDITOR'S NOTE: A previous version of this story misquoted Annette Keys. She said her brother, Mark Herczog, didn't want to call police about son Houston Herczog's unusual behavior because the father feared officers would resort to violence. She did not say Mark Herczog feared his son could turn violent with officers.