What is the risk of depression over a lifetime?

Depression is a common condition around the world. One in three women and one in five men will experience major depression before the age of 65. by Salon Dittany May 18, 2022 

Depression is a common condition worldwide. Between 2 and 6 percent of people have suffered from depression in the last year.


Researchers estimate that around one in three women and one in five men in the United States have an episode of major depression by the time they are 65. Studies in other high-income countries suggest even higher figures. In the Netherlands and Australia, it’s estimated that this affects 40% of women and 30% of men.

In this post, I will explain why measuring the lifetime risk of depression can be challenging, and how researchers are able to address the challenges and estimate the risk of major depression over a person’s lifetime.

Depression is one of the most common health conditions globally. It’s estimated that between two to six percent of people in the world have experienced depression in the past year.

But what are the chances that people have depression at any time in their lives? 

This question is difficult to answer because depression is not a constant condition – people tend to transition in and out of depressive episodes. The chances of ever having an episode of depression are therefore much higher than the figure of two to six percent. 

What are the odds that someone will experience depression in their lifetime? 

It is hard to answer this question because depression isn’t a permanent condition. People tend to go through depressive episodes. is therefore more likely to experience depression than the other two to six per cent.

In other high-income nations, the figures are even higher. It’s estimated in the Netherlands and Australia that 40% of women and 30% of men suffer from major depression. 

This post will explain how to estimate the risk of major depressive disorder over the course of a lifetime. 

Measurement of lifetime depression: challenges 

Asking elderly people if they’ve ever experienced depression can be a good way to estimate lifetime depression risk. It sounds simple, but this leads to a number of problems. 

It relies heavily on self-reporting. Major depression is diagnosed by the symptoms people report to professionals. We would underestimate the risk of depression if we only relied on these symptoms. 

It is especially important for older generations, who spent most of their lives in a time of lower acceptance and recognition of mental illness. This relates to the second problem, which is that people of different generations may be less likely to report symptoms. 

This is especially true for low-income countries. It is particularly true in low-income countries. The Global Burden of Disease Study found that only one quarter of countries had data directly on the prevalence of depression between 2005 and 2015

Our findings are based on a few high-income countries that have conducted these studies.

Even in countries with data, another challenge remains. Man.  People forget previous episodes of depression, especially if they happened many years ago. This phenomenon is known as “recall bias” and is another reason why it’s difficult to trust people when they self-report symptoms of depression. 

This is shown in the chart. This is a study that involved a large number of people being interviewed at different times over varying time periods about the symptoms of mental or physical illness. 

Some people have described episodes of depression that occurred between interviews. Some people failed to remember episodes they had described in previous interviews. The result was that a constant percentage of respondents described depression as a lifetime experience at every interview. 

As expected, people over 60 are more likely than younger people to forget past symptoms. Older people are seven times more likely than younger ones to forget previous symptoms. 

We need to be careful when using survey data – if we don’t adjust for the recall bias we will underestimate the lifetime depression risk.

Estimating lifetime depression risk 

Researchers can estimate depression risk over the lifetime of a person using models. 

Researchers can estimate lifetime risk by estimating how many people have forgotten about a previous episode of depression. This approach was used by Jamie Tam and his colleagues in a study that looked at more recent data. The researchers used self-reported depression rates in the last year and over their lifetimes, along with the rate of recall error. 

This is shown in the graph. Researchers estimated that by age 65, one third of women (33%) in the United States and one fifth of men (19%) will have major depression. The share of people who had a recent episode declines slightly with age. The share of people who forget earlier episodes, however, increases dramatically. 

Other high-income countries have also provided estimates. A 2005 study using data from Australia and the Netherlands estimated that 40 percent of women and 30 percent of men will experience major depression before the age of 65. 

All of these studies have found that the lifetime risk for depression is much higher than what is estimated by asking older people about depression in their past. 

Understanding, recognizing, and addressing depression is crucial because of the significant lifetime risk. Depression is common, and those who suffer from it are not alone. 

The risk does not change over time. Depression is neither inevitable nor irreversible. We can work to reduce its impact on the people who are affected.