Cancer diagnosis and crime refers to the measurable increase in criminal behavior that follows a serious health shock like cancer. A large study of Danish patients found that being diagnosed with cancer increases the likelihood of committing a crime by about 14 percent relative to similar people who were not diagnosed. This “Breaking Bad effect” is driven by both financial pressure and a lower perceived cost of punishment when future life expectancy shrinks.
What makes the finding striking is that the effect is not limited to money motivated offenses. According to economists Steffen Andersen and colleagues, non‑economic crimes like violence and vandalism rise even more than theft and fraud after a cancer diagnosis, suggesting deeper psychological shifts beyond simple financial desperation.1
What is the link between cancer diagnosis and crime?
The “Breaking Bad effect” is the observed pattern that people are more likely to commit crimes after a serious health shock, particularly a cancer diagnosis. In the best studied case, researchers used nationwide Danish registry data to follow hundreds of thousands of individuals before and after they were diagnosed. They compared these patients to similar people who were not diagnosed in the same period, effectively isolating the impact of the health shock itself.2
They found that, on average, a cancer diagnosis raised the annual probability of committing a recorded crime by about 0.10 percentage points, from a baseline of 0.69 percent to roughly 0.79 percent. That sounds small, but it is a 14 percent relative increase in risk, and importantly, the change was persistent for at least a decade after diagnosis rather than a short lived spike.1
The increase showed up both among people with no prior record and among existing offenders, indicating that cancer can nudge some individuals into crime for the first time while also making reoffending more likely. Because the study tracked the same individuals over many years, it could distinguish this effect from general crime trends or aging.
Overall, a cancer diagnosis raised the chance of committing a crime by about 14 percent relative to similar people who were not diagnosed, and this higher risk persisted for years.
How did researchers measure the “Breaking Bad effect”?
The main evidence for the link between cancer and crime comes from Denmark, which maintains detailed nationwide registries on health, income, and criminal charges. Andersen and coauthors used these registries to build an “event study,” a type of analysis that tracks how an outcome changes in the years before and after a specific event, in this case the year of cancer diagnosis.1
They followed individuals from six years before diagnosis to ten years after. Before diagnosis, crime rates for future patients and their matched controls moved in parallel and stayed close to zero relative difference, which suggests the groups were comparable. In the year of diagnosis, criminal activity actually dipped slightly, likely because treatment and hospitalization reduce physical capacity to offend and can be partly covered by savings.
Starting around two years after diagnosis, however, the pattern flipped. Crime rates among patients rose above the pre‑diagnosis baseline and continued to climb through about year five before leveling off at a higher plateau that persisted through at least year ten. This long‑run shift is what produces the average 14 percent increase in the probability of offending.2
Importantly, the study focused on “plausibly exogenous” variation in the timing of diagnoses. That means the researchers treated the exact year someone is told they have cancer as largely random with respect to short‑term financial or criminal behavior, which strengthens the case that the health shock, rather than some hidden factor, drove the change.
In the Danish data, crime rates did not drift upward before diagnosis. The jump occurred only after the health shock, strongly pointing to causation rather than mere correlation.
What kinds of crimes increase after a cancer diagnosis?
If the story were only about paying bills, you would expect health shocks to push people mainly toward economic crimes such as theft, fraud, or drug dealing. The Danish study did find a significant rise in these offenses, but it also recorded an even larger proportional increase in non‑economic crimes.3
Using the data summarized by ZME Science and the authors’ own breakdowns, the researchers estimated roughly a 14 percent increase in economic crimes alongside about a 38 percent relative rise in non‑economic offenses, including violent crime, vandalism, and other acts not directly motivated by money. That pattern suggests that at least part of the mechanism involves changes in risk taking, impulse control, or the way people value the future, not just empty wallets.
The effect also appeared across a wide range of cancer types, but it was strongest for diagnoses associated with steep drops in survival probability. In other words, when cancer is more likely to shorten life dramatically, the behavioral response in terms of crime is larger.2
None of this implies that “most cancer patients turn to crime.” The baseline risk of offending in any given year was well under 1 percent, and the vast majority of patients never committed any crime at all. The finding is about relative risk at the population level, not a prediction about any particular person.
Why would cancer make some people more likely to commit crimes?
The researchers point to two main mechanisms behind the Breaking Bad effect: an economic channel and a survival probability channel. Together, these explain most of the observed increase in criminal behavior after diagnosis.
Economic pressure and income loss
Cancer often forces people to reduce their working hours or leave the labor force entirely, which cuts legal earnings. Even in countries with generous public health systems, lost wages and added costs can strain household finances. Andersen and colleagues found that diagnosed individuals experienced significant declines in income and employment relative to their peers.4
People with limited savings, home equity, or spousal income were especially likely to respond by seeking “illegal earnings” through theft, fraud, or other money‑making crimes. The crime effect was weaker among those with more financial buffers, which supports the idea that at least part of the behavior is a response to economic hardship.
Lower expected cost of punishment
The second mechanism is more psychological but grounded in standard economic theory. The criminal justice system relies on the threat of future punishment to deter crime. If someone expects to live for decades, the possibility of spending years in prison carries a large cost in their internal calculus. A terminal or severe cancer diagnosis, however, sharply reduces expected remaining life.
In technical terms, the diagnosis raises the “discount rate” applied to future outcomes, so future jail time matters less relative to current benefits. The authors summarize this as cancer patients facing a lower expected cost of punishment because there is less future life in which that punishment can be realized.2
This logic can explain why non‑economic and even impulsive crimes also increase. If someone feels they have little future to protect, the deterrent effect of law weakens, and anger, frustration, or a desire for intense experiences can more easily translate into risky or harmful actions.
When people no longer expect to have a long future, the threat of future punishment loses much of its power. That shift in perceived risk helps explain why some, but not most, patients “break bad.”
Does better social support reduce the crime impact of cancer?
One of the most policy relevant findings from the Breaking Bad study is that welfare programs can blunt the link between health shocks and crime. Denmark provides a useful test case because of a 2007 municipal reform that changed local social assistance and disability benefits in ways that varied across regions.
Andersen and colleagues compared patients diagnosed in municipalities where the reform reduced support to those in areas where benefits remained more generous. They found that cuts to social support amplified the crime increasing effect of cancer, while stronger safety nets moderated it.1
This suggests that part of the criminal response is avoidable. If income replacement and disability insurance cushion the financial blow of serious illness, fewer people feel compelled to seek illegal income. At the same time, stable support can ease some of the psychological strain that might otherwise make the future feel worthless.
Because the Danish context already includes universal healthcare and relatively strong welfare institutions, similar or larger effects might arise in countries where medical bills and income loss are more severe. While the study does not directly analyze other systems, many criminologists and public health researchers interpret these patterns as evidence that robust healthcare and social insurance can indirectly lower crime by reducing desperation.
What does the Breaking Bad effect mean for patients and policymakers?
For individual patients, the main takeaway is not that criminal behavior is inevitable after a diagnosis, but that financial and psychological support matter. Access to income replacement, debt counseling, mental health care, and palliative care can all help people cope without resorting to harmful actions. Friends, families, and clinicians should be aware that some patients may feel they have “nothing left to lose,” and should take that mindset seriously.
For policymakers, the evidence that cancer diagnosis and crime are linked adds a hidden layer to the social costs of serious disease. Health shocks do not just affect patients and families, they also create spillovers in the form of increased policing, victimization, and incarceration. According to the American Economic Association’s summary of the study, these externalities persist for many years after diagnosis and are sensitive to changes in social support.1
Designing welfare and healthcare systems that reduce economic desperation is one way to curb this negative feedback loop. Programs that maintain income and provide targeted assistance after life changing diagnoses are not only compassionate, they may also be cost effective crime prevention tools. The Breaking Bad effect, in that sense, is less about individuals “turning evil” and more about how institutions handle people at their most vulnerable.