Who doesn’t want to be a billionaire? A millionaire, even? Think of all the troubles that would simply melt away.

Of course, we know deep down that money won’t solve all of life’s problems. And billionaires, it seems, have problems, too. One difference is, no one is likely to feel sorry for them.

“When you have a billion dollars, of course you’re happy about that,” said Brad Klontz, a psychologist and certified financial planner who works with the uber-wealthy.

As a society, he said, we believe the wealthy have no right to complain about their lives. “We have little patience for that,” he said. “But the truth is, the ultrarich suffer from the same existential angst as anyone else.”

The difference between their angst and ours is that a billionaire can’t indulge in the fantasy that money would make everything better. “Billionaires can look behind the curtain and see the wizard doesn’t exist,” Mr. Klontz said. “More money is not going to make them happy.”

In an effort to gain a deeper understanding of the wealthy, Mr. Klontz was the lead investigator in a study of wealthy individuals (conducted with three others, including Paul Sullivan, a financial columnist for The New York Times), published in 2015. The study found the ultrarich to be deeply conflicted.

“Although they know money is not the key to happiness, they can’t stop counting it,” Mr. Klontz said. It’s especially challenging for those who are self-made, as opposed to those who inherit a fortune. For self-made billionaires, he said, “Their entire self-image and all their self-esteem is wrapped up in the pursuit of money.”

Billionaires often feel isolated, Mr. Klontz said, and find it difficult to trust people or have authentic relationships that are not about money. On top of that, they have a hard time finding a sympathetic ear. “There is a sense they can’t really tell anyone what they are dealing with, because no one wants to hear about their struggles,” he said. “As a society, we don’t have the head space to entertain the notion of a billionaire having a bad day.”

But like everyone else, billionaires do have bad days, and some turn to Mr. Klontz for help.

Mr. Klontz’s interest in helping billionaires and others in their income bracket comes from an unlikely place: his own low-income past. “I came from generations of poverty,” said Mr. Klontz, 46.

“I wanted to see how they and their families were able to pass down a way of thinking and behaving associated with financial success,” he said of the very rich. “My goal was to identify how their psychologies differ to help people achieve their financial goals.”

He generally works with clients of Your Mental Wealth, a registered investment advisory firm in which he is a partner and co-founder. Although he is a certified financial planner, Mr. Klontz does not do any investing for his clients, leaving that to his partners in the firm. Instead, he works with them as coach and consultant. (Mr. Klontz is based on the Hawaiian island of Kauai, so much of his work is done by video conference or phone.)

He and his father, Ted Klontz, also a psychologist, train financial advisers and therapists in their five-course online curriculum in financial psychology and behavioral finance at Heider College of Business at Creighton University in Omaha. And the pair are the founders of the Financial Psychology Institute, which certifies financial behavior therapists, and have written several books, including “Mind Over Money.”

The entire field of financial therapy is still in its infancy, said Megan Ford, a marriage and family therapist pursuing a doctorate in financial planning. She is also president of the Financial Therapy Association.

The association was created by financial and mental health professionals who recognized that each group could benefit from the other’s skill set. The association’s members are trying to figure out how to combine those skill sets — financial and mental health — while protecting consumers. “Like any other blossoming discipline, there is a lot of groundwork that needs to be done,” Ms. Ford said.

Becoming a counselor for the ultrarich was a long journey for Mr. Klontz, who grew up outside Detroit. His parents divorced when he was 2, and his mother, a part-time kindergarten teacher pregnant with his sister at the time, was granted full custody. Although she remarried a few years later to a high school teacher, their economic situation barely improved. Mr. Klontz said they went from being under “tremendous financial strain” to straddling the lower- to middle-class line during the rest of his childhood.

Despite earning a doctorate in psychology, he remained financially strapped, graduating with $100,000 in accumulated student loan debt and a lot of anxiety about it.

But it was 1999, and many of his friends were making lots of money trading stocks. “I thought: This is what rich people do, so I’ll do this, too,” he said. Mr. Klontz sold his truck for about $7,000, bought a $450 car and threw everything that was left into tech stocks. “In three months the bubble burst and I lost everything I invested.”

Rather than blame the market, Mr. Klontz decided to figure out what had caused his behavior. “I went home and interviewed several of my family members about their relationship with money,” he said. “I found stories that blew my mind. But the one that is most salient, is that my grandfather lost all the family’s money in the Great Depression and after that, never put a dollar in a bank again, not for the rest of his life. He died in his 90s, living in a trailer park.”

Mr. Klontz became interested in learning more about his family’s enormous anxiety around money. His mother, for example, had so much anxiety around it that she put every cent she saved into low-interest-bearing certificates of deposit, rather than the stock market. “I saw these patterns around money in families that I call dysfunctional pendulum swing: You either do exactly what your parents did or the exact opposite,” he said. “And that’s what I did: I did the riskiest thing you could do.”

After his stock market gamble, it took him three years of living extremely close to the bone to pull himself out of debt. The desire to understand the financial beliefs and behaviors of his own, lower-income family led him to dissect the behaviors and beliefs of high-net-worth individuals. And now he works with some of the wealthiest people in the world, many of whom came to him after reading his books or being referred by other clients.

Mr. Klontz and his father also repaired their relationship.

When Mr. Klontz was 19, his father bought Onsite Workshops, a treatment center in South Dakota, and Mr. Klontz lived with him while getting his master’s degree in counseling; he also worked in his father’s treatment program.

And now, after all these years, what, if anything, does Mr. Klontz think psychologically separates the super rich from everyone else — understanding, of course, that generalizations by nature don’t give a full picture.

“In many ways, I would say they are just like you and I, if we had a billion dollars,” he said. “Different problems, but not a lack of problems.

“They often have a distorted feedback loop. People are drawn to them for their status and perceived power, so they tend to be surrounded by people who endorse their worldview and don’t challenge their way of thinking. Very few people are honest with them.”