On the wall across from Tucker Johnson’s easy chair is a three-paneled drawing he believes was an early clue to his son’s mental illness, an exacting sketch of the Pillsbury Doughboy, first intact, then split in two, then unrecognizable.

Parks, as his family calls him, was a senior at Rancho Bernardo High School in San Diego when he drew it. When his father asked him what it meant, he said, “That’s how I feel.”

Tucker Parks Johnson Jr. was 24 when doctors diagnosed him with bipolar disorder, a condition marked by wild mood swings. By then, he had walked out on his parents’ deck and announced he was going to jump. He didn’t intend to kill himself -- he thought he could fly.

But the low point of his troubled life wasn’t the year he learned he had a mood disorder, inherited from his mother; doctors found the right combination of antipsychotic drugs to keep him sane. The low point came six years later, when the health insurance industry refused to cover him anymore because he was too sick.

Ever since, every day is a struggle to get along without doctors, to find his medications at the cheapest possible price. He hasn’t seen a psychiatrist in four years, or a dentist in seven. He has nightmares that his teeth are falling out.

Now, Parks Johnson’s best hope is in the hands of Congress. As the Senate prepares to vote on its version of a reform bill, ideas like the “public option” and Medicare expansion are dead.

But no one is talking about dropping the kinds of insurance reforms that will open a new chapter in the lives of sick people like him: those with mental illness, heart disease, cancer, diabetes -- chronic ailments that touch almost every family in America. Those patients are the ones most likely to lose coverage because their policies impose lifetime limits, or because they have, in industry parlance, a “preexisting condition.”

Their pain may continue, their premiums may be high, their diseases could remain incurable, but the legislation President Obama is expected to sign into law next year will almost certainly ensure they have access to health insurance.

“With my situation that’s the best news I could imagine. Health insurance would free me up to go to school, to work. Without it, it’s just too hard,” Johnson said.

Now 34, he is caught in a predicament that pervades the U.S. healthcare system and helped spur the clamor for reform: Those who need coverage the most have the hardest time getting it.

With no affordable care, Johnson’s health deteriorated and he couldn’t work. Because he couldn’t work, he couldn’t get health insurance.

The result: a state-sponsored mental health facility treats his mind for $15 a visit, but not the rest of him. His foot drops from nerve atrophy in his back and he falls down often, giving some the impression he’s drunk.

His last bipolar breakdown came two years ago. All things considered, “it wasn’t a bad one,” his father said. “He was only in jail for three days.”

Parks Johnson lives in the Mississippi Delta, cooking and caring for his grandfather for $200 a week. His bedroom is the one his mother had growing up. His greatest fear is getting sick. To control his weight, he walks daily with his grandfather’s chocolate lab, Dolly, lifting his right foot and setting it down in an awkward gait.

“It’s really scary. What if something happens with my back with no insurance? We’ve got all kinds of collection people sending bills for thousands of dollars now,” Johnson said, having just finished making his grandfather’s lunch.

Back in high school, Johnson’s future looked bright. His oil paintings and sketches were superb. He made the golf team and the honor society. When he won a scholarship to study architecture at Mississippi State, the local paper wrote it up.

But the fast pace of college proved too much. A year later, at 19, he was back home with his parents. Four years after that, he was out on the deck, convinced he could fly. His father recognized signs of the same disease that had afflicted his wife years before and knew his son was bipolar before the doctors announced it.

With the right medication and regular sessions with a psychiatrist, Barbara Johnson was living a full and happy life. After a period of adjustment, it looked as though her son could too. Soon he was back to work driving a warehouse forklift, covered by Kaiser health insurance.

When his godfather offered to teach him the scrap metal business in Atlanta, with Blue Cross coverage, Johnson leaped at the chance to live an independent life: At 28, he got his first apartment. It did not last long.

The treatment that kept his mind healthy made his body a wreck: The drugs caused weight gain -- at 5-foot-9, he ballooned to 290 pounds. He stopped taking the medicine, stopped showing up for work and got fired.

His Blue Cross insurance continued through COBRA, a federal program that temporarily extends coverage after a job loss. His parents paid the $280 monthly premium.

He eventually found a job with health insurance at a furniture warehouse. But before the benefits kicked in, his back gave out -- he jumped to catch a roll of duct tape and pins and needles shot through his legs. An MRI showed a severe narrowing of his spine, aggravated by the added weight. He quit before the first week was up, moved home with his parents and underwent surgery.

That’s when, at 30, Johnson was told, “Enough.” Blue Cross Blue Shield informed him he had hit his lifetime cap. His father’s premium check was returned. The bills stacked up.

When one person loses insurance, it usually becomes a family affair. Tucker and Barbara Johnson built their life around helping their son.

They rent a modest town home in Fairfax City, a Washington suburb, on an annual income of $100,000 -- he’s a surgical technician, she manages a Navy exchange not far from the Pentagon. To help pay their son’s bills, they sold their house to tap the $70,000 profit; they cleaned out a $52,000 retirement account and racked up $47,000 in credit card debt. To rescue him from a breakdown, they dropped everything and drove 16 hours to Greenwood, Miss.

“He’s our son,” Johnson’s father said. “What are we going to do, let him wander the streets and not take his medicine? We couldn’t let that happen.”

Recovered from surgery and desperate for health insurance, Johnson took a job working with an electrician in northern Virginia who promised to pay if he found a plan. He applied to Kaiser, which had insured him before, and was rejected for preexisting health conditions. Several other companies said the same.

Johnson had hit a wall that affects an estimated 46 million people in America who are without health insurance. In his case, no insurance company would take him because he was already sick, even though his father and his boss were willing to buy him a policy.

The law protects people with preexisting conditions if they are covered by group plans provided by their employers -- people like Johnson’s mother. But there are no such protections for those looking to buy individual coverage. More than a third are denied, according to data from the Centers for Disease Control and Prevention.

Kaiser explains its policy just as the overall insurance industry has: Coverage of the sickest patients -- the most expensive -- is only affordable if younger, healthier people are required to participate in the system to spread out the cost.

“The fact that it’s necessary to exclude anyone from coverage to keep it affordable for others is a key flaw of the current system,” said Kaiser spokesman Won S. Ha. “What we support is national health reform that requires insurers to cover everyone, so long as all Americans are required to have coverage.”

The legislation working its way through Congress would make it mandatory for most people to buy insurance, and would impose financial penalties if they do not. The bill also provides subsidies to people of modest means to help make insurance more affordable.

Uninsured, Johnson kept working for the electrical firm. He quit going to doctors and stopped taking his medications, but was so happy in his new jobit didn’t seem to matter. Then he got laid off. Out of options, in fragile health, he moved to Mississippi to take care of his ailing grandfather and got along all right until his grandfather took a fall. Their relationship was thrown into turmoil by the strain of one sick person caring for another. “I just lost it,” Johnson said.

Next thing he knew he was in his truck on the backcountry roads where his dad grew up. “I was not all there, but I was driving. It’s just a weird state of being,” he said.

He had thrown his shirt and right shoe out the window. His mother’s voice on the phone snapped him out of it. She raced to Mississippi and found him in a holding unit of the local hospital, talking to spaceships.

“I felt guilty. I gave this to him,” Barbara Johnson said, holding a piece of her son’s art, her favorite, a lioness etched in black wax, with fur so real it looks wet.

The Johnson family doesn’t like to think about what comes next.

“He can’t go on like this forever. His grandfather is 86. If he should die, then where is Parks going?” the elder Johnson said, holding on to hope that Obama will sign a new healthcare bill into law soon.

That seems more and more likely, but uncertainties remain. Once the bill is passed by the Senate as expected on Christmas Eve, House and Senate negotiators could spend weeks ironing out differences between their respective versions. Among the many issues to be decided is how quickly each of the insurance reforms would take effect -- some could be remedied immediately, others could take years.

For Parks Johnson, the clock ticks. He just hopes he doesn’t get sick before help arrives; he worries about burdening his parents.

“I’m ashamed that they had to go through all that. I’ve been a handful. I don’t want to lay around and do nothing,” he said, while his grandfather took a midday nap, the TV blaring in the background.

faye.fiore@latimes.com

janet.hook@latimes.com