Methamphetamine can trigger schizophrenic-like mental illness, raising legal questions about guilt and punishment when users commit violent acts while hallucinating.

Shad Gary Dunbar, 35, of Rogue River is serving a 10-year prison sentence after chasing and shooting at two Mail Tribune newspaper carriers. Dunbar was experiencing a meth-induced delusion that the carriers he nearly killed had kidnapped his father.

After weighing an insanity defense, Dunbar instead pleaded guilty in July 2016 to four counts of attempted murder and one count of being a felon in possession of a firearm. His home is now a maximum security prison in Salem with 25-foot-tall walls, 10 guard towers and Oregon's death row.

If he had been successful in pursuing a guilty-except-for-insanity defense, Dunbar could instead have been sent to an Oregon psychiatric hospital for treatment and eventual release.

Jackson County Chief Deputy District Attorney Jeremy Markiewicz said the issue of meth psychosis is being raised more often in court.

"I've seen more diagnoses from defense psychologists and psychiatrists in the last couple of years," he says.

Markiewicz says he is concerned defendants diagnosed with meth psychosis could get out of custody too quickly.

"If someone goes into the state hospital with meth psychosis and gets clean and shows no sign of suffering from a mental illness, they could be released in a very short period of time," Markiewicz says.

Dunbar's defense attorney, Clayton Tullos, doesn't discount Markiewicz's concerns.

"That is a very valid concern on the part of prosecutors," says Tullos, who has worked as a prosecutor as well as a defense attorney. "Defendants could be released. They would be subject to monitoring, but they could be back in the community fairly quickly."

However, Tullos says insanity defenses for meth users are not often successful. Usually defendants are still considered legally culpable when they are under the influence of meth.

"Voluntary intoxication is not an excuse," he says.

Science of meth psychosis

Dr. Robert Julien of Lake Oswego has been a consultant and expert witness for defense attorneys on approximately 150 cases over the past decade.

Julien, who specializes in psychopharmacology, says meth triggers an excess of dopamine in the brain.

Dopamine is a neurotransmitter involved in the brain's reward and pleasure centers. Excessive dopamine is also an underlying factor in schizophrenia, a mental illness marked by hallucinations and delusional thinking.

People with schizophrenia often experience auditory hallucinations, such as voices no one else can hear.

Meth hallucinations may involve all five senses. Users can hear voices commanding them to kill, see things that are not there, smell odors like their flesh rotting, perceive odd tastes like poison in their food or feel bugs crawling under their skin — causing them to scratch, gouge or cut their bodies to get at the imaginary insects.

Like Tullos, Julien says voluntary intoxication is generally not legally defensible.

For example, a person who drinks alcohol, drives and kills someone in a crash usually will be found guilty.

Julien says his job is to educate juries about the effects of meth use and meth psychosis.

"Someone with severe schizophrenia is insane. They can't speak for themselves and they can't understand what was going on," he says. "A person with meth psychosis is not much different. They are experiencing temporary insanity. They are not in their normal mind. The problem is getting juries to believe it is not their responsibility because they voluntarily took a drug. The question is, 'Should there be any mitigation of the sentence because they were under the influence of a drug they voluntarily took?'"

Julien says the defense becomes stronger if a meth user has developed chronic meth psychosis. Hallucinations, delusions and paranoia can persist even after the person has stopped using.

"Meth is neuro-toxic and can damage and destroy the brain. It can create long-term, irreversible brain changes. The changes can last up to five to six years in monkeys," he says. "Meth creates temporary or permanent brain damage. Some long-term meth users never seem to be normal people."

Meth not only causes changes to brain chemistry; users often go days at a time without sleeping. Extreme sleep deprivation also can contribute to psychotic symptoms, Julien says.

"They experience paranoia and extreme fearfulness," he says. "People are afraid of anything and anybody."

Julien says he has seen cases where meth psychosis led to violence and tragedy.

"A gentleman was with a prostitute in a hotel room and they were both using. He was in a paranoid state and thought police were hiding behind the curtains. He stabbed her multiple times until she died," Julien says. "He went off the deep end."

Julien says people who consume too much alcohol, a sedative, can enter a blackout state in which they are still moving and speaking, but are unable to form memories of their actions. With stimulants such as meth, users do form memories — but the memories can be distorted recollections influenced by hallucinations and delusions.

Dr. Darryl Inaba, director of clinical and behavioral health services for Addictions Recovery Center in Medford, says meth users can develop the same chemical imbalances seen in people diagnosed with schizophrenia, paranoia, depression and other mental illnesses.

Meth users may believe their roommate is an alien, or may hallucinate that their romantic partner is having sex with another person, he says.

"We've seen some horrendous acts committed. They may believe their brain is controlled from outer space. One young man felt his roommate was stealing his boots and he shot him in the head with a shotgun," Inaba says.

A college student believed his roommate was a narcotics officer and plotted to shoot the roommate. Fortunately, the student didn't carry out the murder, Inaba says.

When it comes to legal culpability, Inaba says courts tend to look at whether a defendant has a pre-existing mental illness, or one that was induced by drug use.

"If they have pre-existing schizophrenia or another mental illness before they started taking drugs, they may be less culpable and there could be less punishment," he says. "If they have a normal brain with no predisposition and they did a criminal act while using meth, the concept is they took the drug knowing the potential and they are fully responsible."

Recovery and treatment

Inaba says the vast majority of people will recover from meth psychosis if they stay off meth.

To counter meth psychosis in the short-term, patients can be treated with anti-psychotic medications that block dopamine. A side effect can be flashbacks, so patients may also receive calming sedatives, he says.

People with an underlying, chronic mental illness may always have unusual thoughts, but their condition can be managed with medication, Inaba says.

Inaba, who works to spread awareness about drug abuse and treatment, has appeared in educational videos by Medford-based CNS Productions, including "Methamphetamine: Neurochemistry & Recovery."

Recovering meth users Brian and Sara, whose last names were withheld, appear in the video.

Brian says he became so paranoid, he stopped taking showers because he was afraid he wouldn't hear anybody coming over the sound of the flowing water.

Sara experienced both visual and tactile hallucinations.

“I swore there was government agents across the street in the park, in the trees with these new high-tech rifles that shot like electric rays, like a stun gun, and I was actually getting physically shocked," she says.

Speaking in an interview, recovered meth addict Jess Campbell says he saw his friends suffering from hallucinations. The Central Point resident now helps others conquer addiction and regain control over their lives.

"I've been with people experiencing meth-induced psychosis. When it does occur, it's quite troubling. People absolutely, hands-down believe the hallucination," he says.

One friend thought someone was living under his house, while another thought a person was hiding in his attic. Another friend hallucinated that her boyfriend was having sexual relations with another woman.

"She was seeing this happening in a car in a parking lot where we were standing," Campbell recalls. "I kept on saying, 'There's nobody there.' Meth psychosis is a very strong psychosis. They very, very much think it's real and there's no talking them out of it. Only once they are off meth do they realize it's not real because the hallucinations stop. But uncertainty about whether it happened or not can be troubling."

Campbell says he got clean 10 years ago after he was arrested and jailed for six months. His mind cleared while he was in jail, and he also sought treatment from Addiction Recovery Center.

Campbell says meth destroys lives and changes people's personalities and morals.

"You become a different person. If you know a person before they start using and after, it's heartbreaking," he says. "You want to get the person back."

Reach staff reporter Vickie Aldous at 541-776-4486 or valdous@mailtribune.com. Follow her at www.twitter.com/VickieAldous.