A Global Map of Winter Depression: 2024 Index Reveals Top Risk Nations

According to the American Psychiatric Association, about 5% of adults in the U.S. experience seasonal affective disorder (SAD) or winter depression, and its symptoms generally start in late fall and last for around 4–5 months.

In the Diagnostic and Statistical Manual of Mental Disorders, this disorder is identified as a subtype of major depressive disorder or a qualifier of bipolar disorder. However, it has a recurrent and seasonal pattern since symptoms occur at a specific time of the year, usually during the fall and winter months. Notably, some people may experience SAD in the summer, known as summer-pattern SAD, but it is less common compared to winter-pattern SAD.

Winter-pattern SAD or winter depression is characterized by symptoms associated with depression, including persistently low mood, fatigue, feelings of hopelessness, and loss of interest in typically enjoyable activities. Additionally, winter-pattern SAD includes specific symptoms such as oversleeping, overeating, and social withdrawal.

Although the American Psychiatric Association states that the most challenging period for people with winter depression in the U.S. is January and February, according to Google Trends, the SAD search term has peaked in November for the last 10 years in the U.S. and globally.

The exact origins of SAD remain unclear; however, researchers suggest that reduced sunlight exposure plays a key role, potentially influencing hormonal shifts and mood regulation. SAD prevalence may also vary depending on genetic factors as well as individual susceptibility.

Winter depression impacts a notable portion of the global population by interfering with daily living and challenging a person’s well-being. To identify countries with the highest risk, the Healthnews team created a global winter-pattern SAD risk index.

A global winter depression risk index

In the report, we conducted a global winter-pattern SAD risk analysis covering data from 194 countries.

The Healthnews team researched the winter-pattern SAD risk factors by analyzing medical and scientific information from the most recent scientific publications and other reputable sources available, including the American Psychiatric Association, the National Institute of Mental Health, and the Centre for Addiction and Mental Health.

By compiling researched information, we selected five risk factors as winter depression risk index metrics: latitude, depressive disorders prevalence, bipolar disorder prevalence, female population size, and 18–30-year-old population size. Please note that risk factors generally have no prognostic potential for any specific person.

The table below summarizes all the metrics we selected.

Why these risk factors?

• Latitude. SAD is suspected to be more prevalent in people who live far from the Equator, where seasonal variations in day length are more significant.
• Depressive disorders and bipolar disorder prevalence. Research suggests SAD is more common in people with a family history of other forms of depression (including SAD) as well as bipolar disorder.
• Female population size. Based on current data, SAD may be more prevalent in women than in men.
• 18–30 years of age population size. SAD appears more common during young adulthood (18–30).

Based on our research and current knowledge of the topic, we also assigned certain weights to the metrics to better reflect their importance. The graph below shows a complete winter-pattern SAD index composition.

The composite index value for each country ranges from 0 to 100. A higher index score suggests that a country has a higher risk of winter depression than a lower index score.

The report's methodology section provides a detailed methodology of our report.

So, are you eager to learn which countries have the highest risk of winter-pattern SAD?

A world map of winter depression risk index

The world map below presents the global risk of winter depression, highlighting each country's rank, index score, and original data values across all analyzed metrics.

Top countries with the highest risk of winter depression

The top-ranked regions include 12 European countries, one from Oceania and two from North America, with Northern European nations leading the list. This pattern could emphasize the role of limited daylight in these areas, potentially placing them at the highest risk worldwide.

Fourteen of the top 15 countries have the highest latitude scores, which may highlight the link between geographic position and winter depression vulnerability.

Interestingly, one Southern Hemisphere country is also in the top 15. SAD prevalence in the south of the Equator is far less studied than in Northern Hemisphere regions. This finding could broaden our understanding of SAD's global risk and may suggest a need for further research on SAD risk in the Southern Hemisphere.

#1 Greenland

Greenland’s winter-pattern SAD risk index score of 79.7 is the highest globally, putting it at the top of our list. An autonomous territory of Denmark located in the Arctic, Greenland experiences some of the world’s longest periods of winter darkness. It also ranks first in the world for the highest latitude, meaning it is the farthest country from the Equator, and second for the prevalence of depressive disorders.

#2 Finland

Finland is a Northern European country that borders Sweden and Norway to the north and Russia to the east. Its SAD risk index score is 69.3 — significantly lower than Greenland's. Finland is quite far from the Equator since its latitude rank is 3rd in the world.

#3 Sweden

The third country on the list is Sweden, a Northern European country located on the Scandinavian Peninsula. Sweden's risk index score for winter depression is 67.1. Together with Norway, Sweden shares spots in the top 5 in the world for latitude. The country also has a quite high prevalence of bipolar disorder, placing it in the top 30 list globally.

#4 United Kingdom

The United Kingdom is a country in Northwestern Europe off the coast of Continental Europe. It scores 64.6 on the winter-pattern SAD index. Ranking 12th in latitude and 6th for bipolar disorder prevalence in the world, the UK secures a spot in the top 5 countries most affected by winter depression.

#5 Norway

Norway, another Northern European country, has a winter-pattern SAD index score of 63.1, placing it 5th on the list. Like other Nordic countries, Norway has a high global latitude rank placing it in the top 5 globally.

#6 Iceland

Iceland, a Northern European island nation between the North Atlantic and Arctic Oceans, received a winter-pattern SAD index score of 62.9. It ranks 6th globally for winter depression risk and 2nd for latitude. Interestingly, Iceland has a very low prevalence of depressive disorder globally, ranking between 150th and 163rd. This contrasts sharply with Greenland, which ranks 2nd in the world for depression prevalence. However, Iceland does fall within the top 50 globally for bipolar disorder prevalence.

#7 Canada

With a winter depression risk index score of 62.0, Canada, the world's second-largest country by total area, ranks 7th globally. Besides being far away from the Equator, which is in the range from 6th to 7th globally, Canada has quite high prevalence of bipolar disorder, which places the country 56th in the world.

#8 Lithuania

Lithuania is the largest Baltic nation in Northern Europe. Its winter-pattern SAD risk index score is 60.7. The country also ranks in the top 50 worldwide for the prevalence of depressive disorders, and it is 6th in the world for the female population size.

#9 Denmark

Denmark is yet another country on the list from Northern Europe. It received a winter-pattern SAD Index score of 60.5, close to Lithuania’s result. Besides its high latitude rank globally, Denmark also saves a spot in the top 50 for bipolar disorder prevalence in the world.

#10 Ireland

Ireland, an island in the British Isles located in the North Atlantic Ocean in Northern Europe, ranks 10th globally. Its risk index score for winter depression is 59.3. Ireland also ranks in the top 15 globally for the highest latitude.

#11 Latvia

Latvia is yet another Northern European country located near the Baltic Sea. Its winter-pattern SAD risk index score is 58.9, ranking it 11th in the world.

#12 Estonia

Estonia, like other Baltic countries, also makes our top list with a winter-pattern SAD index score of 58.7.

#13 New Zealand

New Zealand is an island in the southwestern part of the Pacific Ocean, located southeast of Australia’s east coast. With a winter-pattern SAD risk index score of 58.2, it ranks 13th worldwide and is the only country from the Southern Hemisphere in the top 15 list. The country’s latitude score is the lowest compared to other top 15 countries in this list. However, New Zealand ranks 1st in the world for the prevalence of bipolar disorder.

#14 Netherlands

The Netherlands is situated near the North Sea in Northwestern Europe. It received a winter depression index risk score of 57.9. Such results save the country a spot in the top 15 globally.

#15 Belarus

Belarus is the only Eastern European country that saved a spot on the top list. The country has a winter-pattern SAD risk score of 57.9, which ranks it 15th globally. Compared to all the countries in the top 15 list, Belarus has the largest female population, placing it 3rd globally.

A risk of winter-pattern SAD: global trends

A Healthews study of winter-pattern SAD risk could closely match what people are searching for online. According to Google Trends analysis, six out of the top 10 countries with the highest index score of winter depression also rank in the top 15 Google searches for the term ‘seasonal affective disorder’ over the past five years.

This overlap suggests that our study may effectively reflect real-world concerns, especially in regions where SAD may be the most prevalent. By reflecting on these trends, our study may identify high-risk areas and respond to the genuine interest of people experiencing winter depression firsthand.

However, there are notable exceptions. According to our research, Iceland ranks 6th globally for winter depression risk, yet it does not appear among the top countries for SAD term searches on Google. Additionally, Iceland has a very low prevalence of depressive disorders, and studies suggest limited seasonal variation in anxiety and depression among Icelanders, implying that other factors may also influence winter depression patterns.

Below is a summary of the complete data, offering insights into global winter-pattern SAD risk trends and regional patterns.

Methodology

The Healthnews team conducted the study using the steps below:

1. Conducted winter-pattern SAD risk factor research by analyzing the most recent medical and scientific information available
2. Selected metrics for the index based on the results of risk factor research
3. Collected the most recent data available for each metric for all countries from reputable sources
4. Analyzed the data quality and statistical parameters (data distribution measurements and outliers)
5. Examined the correlations between selected metrics
6. Conducted the metric data transformations (if needed) and checked the statistical parameters and correlations afterward
7. Standardized all the metric data to 0–100 ranges by Min-Max normalization method
8. Assigned weights to the metrics and calculated index scores for each country
9. Evaluated the reliability and stability of the index calculation method

Additionally, we conducted a worldwide Google Trends analysis of the five years from 11/11/2019 to 11/11/2024, using the search term ‘Seasonal Affective Disorder’ in all web search categories.