Monday September 5 2011
In Europe, 38% of people have a mental disorder
“Europeans are plagued by mental and neurological illnesses, with almost 165 million people or 38% of the population suffering each year from a brain disorder such as depression, anxiety, insomnia or dementia, according to a large new study,” reports The Daily Telegraph.
The news report is of a large study that reviewed the research to date and surveyed national experts to estimate the size and burden of mental health and neurological disorders in Europe. It found that 38% of the EU population suffers from mental disorders, and that these conditions account for about 26.6% of the total disease burden in Europe. The authors also found that women and men suffer from different mental disorders (depression being more common in women and alcohol misuse in men).
These figures are estimates only, but are the result of rigorous analysis by experts in the field and are likely to be accurate. The high numbers reflect the need for further basic, clinical and public health research into prevention and treatment. The study did not examine the reasons behind the high rates of mental disorders, such as the rate of depression in women. The authors suggest that these high rates may be due to the increased pressures of marriage, family and job, but this would need verification in further studies.
Where did the story come from?
The study was carried out by researchers from a variety of international research institutions and was commissioned by the European College of Neuropsychopharmacology. The study was also funded by H. Lundbeck A/S and the European Federation of Neurological Societies. The study was published in the peer-reviewed medical journal European Neuropsychopharmacology.
The results of the study were covered by several newspapers. Many of the reports comment on the finding that women are more likely to suffer from depression than men, and attribute this to women now having the burden of marriage, family and a job. It is important to point out that the link between the increasing rate of depression and changes in social patterns is only a theory given by one of the lead researchers, and this is not demonstrated in the research paper.
What kind of research was this?
This was a systematic review of literature combined with re-analyses of data sets, national surveys and expert consultations from all 27 member states of the European Union (EU) plus Switzerland, Iceland and Norway. It aimed to provide the 12-month prevalence (total number of cases in the population) of a broad range of mental and neurological disorders in the EU. This was an appropriate study design for this question.
What did the research involve?
The researchers had published a similar review in 2005, but decided to carry out a 2011 update as the earlier review was limited in that it only covered people between the ages of 18 and 65, missing out children and the elderly. It also had not considered a number of other mental health and neurological conditions (including those that are age-related, such as attention-deficit-hyperactivity disorder and dementia).
For the current review, a panel of 19 experts conducted a systematic review of the literature to identify studies (published 1980 to 2010) that had used a clear sampling strategy to look either at a sample of the general population or a community. To be eligible, studies had to have assessed the prevalence of mental health and neurological conditions that had been diagnosed using valid diagnostic criteria. The panel verified that no new study published before 2004 had been identified that had been missed by their earlier 2005 review. As some publications did not contain prevalence data in the manner that they needed, they also re-analysed some original study data from countries participating in the ESEMeD project (a large scale, cross-national study of common mental disorders in several European countries) and the Mental Health Supplement of the German National Health Interview and Examination Survey. They also surveyed national experts from all 27 member states of the EU plus Switzerland, Iceland and Norway, to validate their review findings, as well as guiding them towards additional data that they may have missed.
What were the basic results?
The researchers estimated that every year, 38.2% of the EU population suffers from a mental disorder. The most frequent mental disorders across all age groups were anxiety disorders, depression, insomnia, somatoform disorders (characterised by physical symptoms that suggest physical illness or injury that cannot be explained by a medical condition, and including conditions such as hypochondria), alcohol and drug dependence, dementias, mental retardation (also termed intellectual disability disorder and characterised by a deficit in cognitive functioning before the acquisition of skills through learning), and childhood or adolescent disorders (including attention-deficit-hyperactivity disorder and other hyperkinetic disorders).
Of the adult disorders investigated, with the exception of alcohol and substance use and psychotic disorders (for example schizophrenia), women were on average two to three times more frequently affected by mental disorders than men.
When both mental disorders and neurological disorders (including dementia, epilepsy and multiple sclerosis) were considered, the researchers estimated that they make up 26.6% of the total disease burden in the EU (30.1% of the disease burden in women and 23.4% in men). Overall, the most disabling single conditions were depression, dementias, alcohol use disorders and stroke, although the order differed with gender and age. The most disabling single condition in women was depression, causing 1 in 10 healthy years of life to be lost. Alcohol use disorders were the most disabling conditions in men.
The researchers explain that although the estimate of 38.2% of the EU population having a mental disorder is higher than that found in the 2005 review, this is because the previous estimate was only for individuals aged 18-65. The present study aimed to look at the whole population, and therefore 14 new disorders, covering childhood and adolescence as well as the elderly, were included. When the rates for just adults aged 18-65 years old were compared, there was no difference between the 2005 and 2011 rates, suggesting that there has been no increase or decrease in rates of mental disorders.
The researchers also discuss the findings, from other studies, that only half of patients with a mental disorder receive professional attention.
How did the researchers interpret the results?
The researchers conclude that “mental disorders as well as neurological conditions must be considered to be Europe’s foremost health challenge of the 21st century”.
This good quality systematic review estimated the size and burden of mental disorders and other disorders of the brain in Europe in 2010. It found that 38% of the population suffers from mental disorders, and that disorders of the brain account for about 26.6% of the total disease burden. It also found that women and men suffer from different mental disorders (depression being more common in women and alcohol misuse in men). When methodological differences in the conduct of the review are taken into account, the results of this study are similar to those of a 2005 study, demonstrating that there has been no increase or decrease in rates of mental disorders.
Although the true prevalence of mental health and neurological disorders may differ slightly from that presented here, due to the fact that this is based on only the sample populations looked at by individual studies and surveys, these findings may be considered to be reliable estimates. The fact that the people in the studies were required to meet valid diagnostic criteria for the conditions increases the faith that we can have in these estimates. However, based on these results no assumptions can be made about the causes of the mental health burden, and debates in the news that these could be due to various life stresses are speculations only.
This study demonstrates how great the prevalence and burden of mental and neurological disorders is today, highlighting the need for further basic, clinical and public health research into prevention and treatment.