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Lack of Access to Mental Health Treatment Reduces Lifetime Income

In 1976, Denmark began providing lithium to people with bipolar disorder through its universal healthcare system. That change in policy allowed Prof. Barbara Biasi and her co-authors to investigate the effects of untreated mental illness on income, by comparing the earning trajectories of people who began their careers before and after treatment was made available. They found that those who couldn’t access treatment paid a price over the course of their careers—suggesting that lack of access to care can worsen economic inequality.

A bottle of lithium medication surrounded by capsules

One in five Americans lives with a mental illness, according to figures from the National Institute for Mental Health. But Prof. Barbara Biasi says these illnesses are too often treated as secondary to the types of physical conditions that can be straightforwardly assessed with a stethoscope or blood-pressure cuff—by policymakers as well as by doctors.

“Mental health conditions have also received less attention from policymakers,” Biasi says. “It’s still a little contentious as to whether access to mental health treatment should be part of people’s insurance plans, for example.”

As a result, the gap between who needs mental health treatment and who receives it remains wide. The World Health Organization estimates that in low- and middle-income countries, 76-85% of people with mental health disorders receive no treatment. In the U.S., fewer than half of those with mental illnesses get the treatment they need.

In a new paper, Prof. Barbara Biasi and her co-authors, Michael Dahl of Aalborg University and Petra Moser of New York University, seek to measure some of the damage caused by this lack of treatment.

“We thought it was really important to quantify systematically what the penalties are, even just in terms of people’s careers and productivity, to hopefully inform the debate about access to treatment,” Biasi says.

To do this, the researchers looked to a landmark medical moment in Denmark: when, in 1976, the Danish Medicines Agency approved lithium as a maintenance treatment for bipolar disorder, making it widely available through the country’s universal healthcare system.

“What the results are saying is that if mental health conditions go untreated, then the people who are going to suffer the most are the people who are already worse off now.”

Using information from Danish registries about citizens’ earnings, diagnoses, and prescriptions, the researchers sought to determine whether access to lithium affected earnings, and if so, to what extent. Biasi and her colleagues zeroed in on the age of 20 as a significant one: not only does the typical age of onset for bipolar disorder fall between 18 and 20 but labor research has also pegged this period as foundational in predicting future wages. The researchers sought to determine whether people who hit the critical age of 20 before lithium’s approval traced a different income trajectory than those who did have access to the drug at that age.

Their findings suggest that, indeed, the availability of treatment played a major part in shaping those trajectories. Access to lithium at the formative ago of 20 eliminated nearly a third of the earnings penalty associated with bipolar disorder. It also reduced the risk of falling into the lowest 10% of earners by 13% and shrunk the risk of zero earnings by 33%. The benefits were strongest for people with the most severe cases of the disorder and for those from families low on the socioeconomic spectrum.

Biasi says the findings suggest that access to mental health treatment can be a powerful tool for reducing economic inequality.

“The findings speak to the case of places like the U.S.”—those without universal healthcare—“because basically what the results are saying is that if mental health conditions go untreated, then the people who are going to suffer the most are the people who are already worse off now.”

The researchers started with a data sample that contained information about mental health diagnoses, earnings, and disability payments for the roughly 2.5 million people born in Denmark between 1946 and 1975. Of those 2.5 million individuals, 18,729 (0.7%) had been diagnosed with bipolar disorder. The data in these registries covered the decades between 1995 and 2015, starting two decades after lithium was approved as a treatment for bipolar disorder.

The researchers examined how the incomes of people who did or did not have access to lithium at age 20 diverged from 1995 onward.

“If I am 20 and I’m showing symptoms of BD and I don’t have access to medication—even if I eventually will have access when I’m 50—my career is likely going to be much different than if I’m 20 and my doctor gives me lithium to treat my BD,” Biasi says. “This is essentially the hypothesis we’re testing, and we find evidence in support of it, because what we see is that people who take lithium in our data but were born in different cohorts have much different earnings.” The impact of the approval of lithium remains significant even after controlling for cohort effects—that is, the various reasons why people in different age groups are likely to post different earnings.

The researchers investigated two possible mechanisms behind the results: Were the earnings of people with bipolar disorder dampened over time because of what labor researchers call the “scarring effects of unemployment”—the lasting effects of a period of unemployment even after returning to work? Or were their earnings lower because they were, more simply, often too sick to go to work? The researchers compared the earnings of people with a single diagnosis of bipolar disorder and some history of unemployment with the earnings of those with multiple diagnoses and no unemployment, and found that the earnings penalties sustained by the latter group were significantly larger. This suggests that the disorder dampened incomes by forcing people to stay home, perhaps for long periods, rather than through any long-lasting impacts of unemployment. This conclusion was strengthened by the separate finding that people with mental health disorders are much more likely to receive disability payments than the general population.

“Our results are an argument for providing people with care. The lack of provision of these types of services in the U.S. is likely to perpetuate and even exacerbate earnings inequality.”

Biasi says the takeway of the research is simple: “Our results are an argument for providing people with care,” she says, whether through an employer-sponsored insurance plan, through a government program like Medicaid, or by some other means. She expresses hopefulness about research finding that recent expansions in Medicaid eligibility to cover psychotropic prescription medications has increased those prescriptions by roughly 22%—but says that more work needs to be done.

“A large portion of the U.S. population is still uninsured,” she says, “and the lack of provision of these types of services in the U.S. is likely to perpetuate and even exacerbate earnings inequality.”

Department: Research