Will a quarter of us suffer from a mental health problem in our lifetimes?

"One in four of us will have a mental illness at some point in our lifetime."

Ed Miliband, 29 October 2012

Labour Leader Ed Miliband used his first public speech since his Party's conference to speak about mental health, an issue which he said politicians had kept silent about for too long.

This, he claimed, was impossible to justify given the scale of a problem which supposedly affects a quarter of us in our lifetimes.

But are mental health issues as prevalent as this suggests?

Analysis

Helpfully, Mr Miliband names the source that he used to gauge the scale of the challenge: the World Health Organization (WHO).

Sure enough, the statistic is certainly one that the WHO has used before.

However tracking down exactly where this figure comes from and what it means isn't quite as straightforward.

One commonly quoted source is the Organization's 2001 World Health Report, which focussed on the issue of mental health.

This did find that "one in four families has at least one member currently suffering from a mental or behavioural disorder," however this isn't quite the same statistic as the one used by Mr Miliband.

Elsewhere, the WHO reports that "one in four patients visiting a health service has at least one mental, neurological or behavioural disorder." Again, while the figures match up with the Labour Leader's, the meaning isn't the same.

To clear up the confusion we got in touch, and a spokesperson for the Organization provided us with a paper on mental health prevalence which they suggested was the best source for the figure.

This study looked at 17 countries, and considered anxiety disorders, impulse control disorders, mood disorders and substance use disorders. It found that over the course of a lifetime, the prevalence of individuals suffering from any of these disorders ranged from 12% in Nigeria to 47.4% in the United States.

This obviously represents quite a wide range, although we can narrow it slightly by looking at the interquartile range - discarding the outlying data in the top quarter and bottom quarter - which puts the prevalence between 18.1% and 36.1%.

While this doesn't give as precise a figure as the quarter singled out by Mr Miliband, it does suggest that he is in the correct ballpark, and the figure may actually be higher.

However we need to be a little cautious in how we apply these findings. As the study states:

"The estimated lifetime prevalence of having one or more of the disorders considered here varies widely across the [surveyed countries], from 47.4% in the United States to 12.0% in Nigeria."

This, the WHO spokesperson made clear to us, means that it is difficult to take the average prevalence and apply it to any one country individually.

In fact, if Ed Miliband was looking to these findings to give an indication of the proportion of us likely to be affected by mental health issues in the UK, there is an even more fundamental problem: the UK wasn't even one of the 17 countries studied for this report.

The closest approximation we can arrive at is to look at the results for our neighbours in Europe, where the prevalence of mental health issues ranged from 19.4% (Spain) to 37.9% (France). Again, while this might suggest that the 'one in four' figure is in line with what we might expect for the UK, this study isn't enough to support a deeper analysis of the UK's position.

Is there any UK-centric data?

While UK-wide information is difficult to come by, similar attempts to measure the scale of mental health problems in England have been undertaken by the NHS Information Centre through its Adult Psychiatric Morbidity in England studies.

The most recent report, from 2007, found that:

"Just under a quarter of adults (23.0%) met the criteria or screened positive for at least one of the psychiatric conditions under study."

Again, while this is very similar to the figure used by Ed Miliband, its meaning is slightly different to his claim.

Firstly this doesn't measure the proportion of people who will suffer from a mental health problem throughout their lifetimes, but rather the proportion who had reported one or more of the conditions under the microscope to researchers via a survey.

Secondly, its worth noting that the NHS Information Centre's study considers a slightly more expansive understanding of mental health issues, encompassing conditions such as gambling addiction and eating disorders.

Conclusion

While research on the proportion of UK citizens likely to be afflicted by a mental health disordered is somewhat thin on the ground, Ed Miliband's claim that a quarter of 'us' will suffer from a condition does fall within the bounds suggested by the studies that have been done.

While the data offered by the World Health Organization - the source suggested by Mr Miliband - possibly indicates that the proportion could be higher than the one claimed by the Labour Leader, we do need to be careful when applying this specifically to the UK.