Michael Swanson, the 18-year-old who murdered two Iowa gas station clerks last year, has been sent back to a prison mental health center after he swallowed 24 painkillers, his mother said this week.

The teen from St. Louis Park has had bipolar disorder with psychotic features diagnosed by a prison psychiatrist and is taking lithium, a mood stabilizer, she said.

That is the type of treatment his parents sought from doctors for months before Nov. 15, 2010 -- when Swanson left home in his parents' Jeep, stole guns from the family cabin and drove to Iowa, where he shot Vicky Bowman-Hall, 47, in Algona and Sheila Myers, 61, in Humboldt.

Whether earlier treatment would have prevented the slayings is far from clear, but Bob and Kathy Swanson will ponder that question for Michael's eternity in prison.

The thought has even dawned on Swanson, according to a letter he wrote his mother.

"I got some good news!" he wrote last month. "I talked to a psychiatrist and he diagnosed me with bipolar and he prescribed me lithium. It is about [expletive] time. The pills mellow me out but ... apparently if you need to get on meds for bipolar and you're under 18, you need to kill some people, cause a media sensation and get put into ... prison."

The paradox of the Swanson case is that he is wrong on that point. The rate of children medicated for bipolar disorder has skyrocketed over the past decade -- to the point where doctors now worry that many children have been mislabeled with the disorder. But something about Swanson, a child whose bizarre behaviors surfaced in his toddler years, prevented his diagnosis, even though bipolar runs in his family.

After receiving a life sentence on July 7, Swanson was transferred to the Iowa Medical Classification Center in Coralville, then moved Sept. 8 to a state prison in Fort Madison. The following week, he swallowed 24 Excedrin Migraine pills he bought from the prison commissary.

Kathy Swanson recalled the way her son explained his actions in a phone conversation this week: "I took those pills and I figured I'd either die or I'd go to the hospital. And I was OK with either one of those outcomes."

Swanson swallowed the pills shortly after learning that his parents had been denied the right to visit him based on the conclusion that they were victims of his crimes. (Swanson had stolen their Jeep.) The decision was overturned when Swanson's parents protested, but his mother believes it made him feel alone and scared.

Swanson was returned to the Coralville observation center after the overdose.

A state prison spokesman, Fred Scaletta, confirmed that Swanson was moved for "behavioral issues" but said privacy laws prevented him from discussing Swanson's health.

Divided experts

Swanson drew national scorn for his careless attitude following the killings, including the smirks he displayed in court and his "y'all are funny" comment to the news media.

Over time, details emerged about his childhood of drug abuse and criminal activity -- and the many plans for long-term mental health treatment on which the courts and doctors never followed through.

Records show a split among mental health experts -- those who believed he had a treatable disorder, and those who believed there was no illness underlying his pathological choices.

A PrairieCare psychiatric assessment in April 2010 suggested he suffered from bipolar disorder, but Swanson didn't receive treatment for it in the subsequent months when he was confined for previous crimes to the Hennepin County Home School.

Shortly before Swanson's release from that facility, the school's consulting psychiatrist, Dr. Jonathan Jensen, assessed the teen as bipolar. He wrote that Swanson was a risk for stealing guns and robbing people and "without any psychotic medication he may carry out these behaviors."

Jensen met with Swanson and his mother on Nov. 3, the day of his discharge, but opted against immediate treatment. He encouraged the Swansons to enroll their son in his colleague's research-based mood disorder clinic at the University of Minnesota, and to initiate treatment after a follow-up appointment in December.

"To me," his mother said, "this was all preventable."

'My Mike'

Kathy Swanson believes her son's behavior during his trials reflected nervousness -- a characteristic noted in his childhood psychological profiles -- and bipolar mania.

She recalled saying goodbye to him in the secured garage of the Carroll County Courthouse after his trial.

"He was just blank," she recalled. "You know, I'm crying and I'm looking at his face and he was just not there."

Kathy Swanson didn't see her son again until late September, when prison officials notified her that she not only would be allowed regular visits with her son, but was urged after his overdose to visit him immediately.

She worries about his safety, especially among inmates who watched the news and saw his antics during the trial. She worries he might hurt himself again.

The visit went well, though, and she is hopeful that the long-awaited treatment is helping.

"He was just happy to talk to somebody," she said. "Talking to him was talking to my Mike again. I don't think I've seen my Mike in almost two years."

Jeremy Olson • 612-673-7744