Is bipolar disorder really increasing?

The most comprehensive and rigorous epidemiological database on the planet is the Global Burden of Disease (GBD) study. It is conducted by the Institute for Health Metrics and Evaluation (IHME), based in Seattle. The latest major data cycle covers 30 years, from 1990 to 2021. We rely on these numbers because they represent the most reliable source for comparisons over time and across regions.

What does the GBD 2021 say about bipolar disorder?

Take a moment to consider these numbers. The absolute number of people affected worldwide has increased by 78 percent in 30 years. However, the age-standardized prevalence has only increased by 0.05 percentage points. This is the smallest possible change. What happened?

Rigorous decomposition analyses of the GBD data, conducted by international research groups, reached a clear conclusion. More than 84 percent of the absolute increase in case numbers can be attributed solely to population growth and changes in age structure. Not to an increase in biological risk.

In other words, there are more people on the planet, the population is aging; the age cohorts in which bipolar disorder is most commonly diagnosed are larger than ever before. Therefore, there are more diagnoses. This is not the same as the disease becoming more aggressive or more common.

It is important to emphasize this, because the difference between “more cases” and “more disease” is fundamental to public health. If the biological prevalence remains stable, the public health response will be different than if the disease is actually increasing.

One of the most interesting findings of the GBD 2021 concerns the socio-demographic index (SDI), a composite measure that combines income, education, and fertility. Regions with a high SDI (Australasia, Western Europe, North America) consistently report the highest age-standardized rates of bipolar disorder. New Zealand, Australia, and the Nordic countries are at the top of the list.

Does this mean that wealth causes bipolar disorder? No. The reasons are structural:

In developed countries, the diagnostic infrastructure is better. They have more psychiatrists per capita, more therapeutic capacity, and better training for general practitioners in early detection.

In developed countries, the diagnostic criteria are more modern. The transition to DSM-5 is happening faster, which expands the “diagnostic net” and captures milder forms of the spectrum.

In developed countries, the stigma is lower. People are more likely to seek help. This refers to the registered rates in health databases, not the actual biological rates.

In countries with a low Socio-Development Index (SDI), many cases of bipolar disorder never come to the attention of a doctor or physician. The condition exists, but it is not included in the statistics. As the healthcare infrastructure develops, the numbers increase. This is not a new disease; it’s people who are finally receiving treatment, therapy, and thereby increasing the number of people actively being treated.

There is a concerning aspect. Although the absolute numbers remain low in countries with a low SDI, these countries are currently experiencing the fastest relative growth in the burden of bipolar disorder. Population growth, urbanization, the stress of globalization, and at the same time, fragile and understaffed healthcare systems, create a volatile combination.

Bayesian predictive models used in GBD analyses project that the global increase in incidence, prevalence, and disease burden will continue at least until 2035, and very likely until 2050. These are the countries that will be least prepared for this surge.

If the biological prevalence remains stable, why are clinicians in Vienna, Berlin, London, Zagreb, and Sarajevo all saying they are overwhelmed, that the number of patients has doubled, and that emergency rooms are overflowing?

Because biological prevalence is not the same as clinical visibility. There is a difference between the number of people who have a biological predisposition and the number of those who need help or hospitalization at a given time. Clinicians are overwhelmed because there are too few of them in the public healthcare system. Therefore, it is extremely important that there are more professionals in the public healthcare system, and this can only be achieved by investing public funds into the public healthcare system.

However, two phenomena are driving up clinical visibility:

1. Reduced tolerance for dysfunction

Society is less tolerant of unproductivity, irregularity, and emotional instability. The pressure to perform well in work, academic results, and “functionality” is greater than ever before. When someone starts to fall out of rhythm, they are referred to a doctor sooner than before.

2. External macro-stressors

The OECD reports in its recent reports on historically high levels of reported mental distress in the EU and OECD countries. The main causes are the COVID-19 pandemic, climate anxiety, wars on the fringes of Europe, the cost of living crisis, and growing socio-economic inequalities. These external stressors act as epigenetic (external) triggers, which can trigger symptoms in people with a biological predisposition.

In other words, the illness is not new in some people, but rather triggered by external factors. A person who might have had a more stable phase in a more stable society may experience an acute episode in a toxic environment and become a statistic.

Headlines such as “Mental disorders are exploding” conflate the biological reality with the clinical demand. Headlines can be technically correct because more people are seeking help in psychiatric practices. The suggested sensational narrative (“our generation is biologically more at risk than ever before”) is not supported by the data, or by its actual meaning.

What does this understanding mean for public healthcare? It means the following:

Investing in the expansion of public health infrastructure (more psychiatrists, shorter waiting lists) is more urgent than the biological research of new medications.

Destigmatization is literally a tool of public health. More people seeking help means fewer untreated cases, fewer suicides, less suffering, and lower societal costs.

Attention to macro-stressors is not a “soft topic.” Economic policy, climate policy, and peace policy have a measurable impact on the incidence of mental disorders, which is why individual civic awareness and responsibility are crucial, alongside responsible work by political structures.

In the next section, we will delve from the global level to the personal level. What bipolar disorder actually does in everyday life. How it destroys school, work, relationships, and finances. And, importantly, how it manifests in the digital environment that we have built over the past 15 years. Why the TikTok algorithm can trigger a manic episode, and why sleep has become one of the most underestimated, if not the most underestimated, “remedies” for mental health.

If the numbers in this article seem abstract to you, but you observe something in yourself or in your environment that looks like the better-described story from part 1 or 2, then that is not a coincidence. A conversation with a general practitioner or a psychiatrist is the first step. In Austria, you can contact Pro Mente Wien (https://promente-wien.at) or call the telephone crisis counseling service 142 (telephone helpline, 24/7, free of charge).

Is bipolar disorder actually increasing?

The absolute number of people affected is increasing worldwide, but the biological prevalence (measured by the age-standardized rate) is only increasing slightly. According to data from the IHME’s Global Burden of Disease Study in 2021, the age-standardized prevalence increased from approximately 0.44 percent in 1990 to approximately 0.49 percent in 2021. More than 84 percent of the increase in the absolute number of people affected can be attributed to the growth of the global population and changes in the age structure, not to a biological increase in the risk of developing the disorder.

The high rates in developed countries are the result of a better diagnostic infrastructure, more modern diagnostic criteria (the DSM-5 expands the spectrum), and less stigma, which encourages people to seek help. It’s not that the disorder is more common in wealthier countries, but rather that it is better recognized there. In poorer countries, many cases never enter the healthcare system.

What does “mental health epidemic” really mean in media headlines?

The term usually refers to an increased clinical visibility, the number of visits to psychiatrists, and hospitalizations, not to a biological increase in the disorder. The main reasons for the increased visibility are a lower societal tolerance for dysfunction, less stigma associated with seeking help, and the influence of macro-stressors such as the pandemic, economic uncertainty, and climate anxiety on people with a biological predisposition.

This is part 3 of the series “Call Me By My Name” on the iks.haus platform. Part 4: “Work, Love, and the Digital Whirlpool” will follow.

Institute for Health Metrics and Evaluation. Global Burden of Disease Study 2021. IHME, 2024. World Health Organisation. Mental Health Atlas 2021. WHO Press, 2022. OECD. Health at a Glance: Europe 2024. OECD Publishing, 2024. GBD 2019 Mental Disorders Collaborators. Global, regional, and national burden of 12 mental disorders in 204 countries and territories, 1990 to 2019. The Lancet Psychiatry, 2022.