more_vert
The Brisbane-based team quantifying mental disorders for the Global Burden of Disease Study (GBD) has identified that somatoform disorders — a group of mental disorders characterised by physical pain with psychological causes — are likely to be second only in mental health to depression burden of disease.
InSight+ spoke with the researchers, who would like somatoform disorders to be represented in the GBD.
Somatoform disorders — or somatic symptoms and related disorders (SSRD) — are often characterised by a patient’s feeling or showing physical symptoms that are influenced by psychological factors, rather than simply having a clear medical cause.
A/Prof Damian Santomauro leads the Epidemiology and Burden of Disease Research team at the Queensland Centre for Mental Health Research (QCMHR), which reports to the Institute for Health Metrics and Evaluation (IHME), University of Washington, for the GBD.
The team oversees the 12 mental disorders represented in the GBD, including major depressive disorder, dysthymia, anxiety disorders, bipolar disorder, schizophrenia, autism, conduct disorder, ADHD, bulimia and anorexia, and intellectual disability.
“The GBD is the largest study in the world to quantify disorders and diseases, including prevalence, age, sex, location, and year,” said A/Prof Santomauro.
The UQ team recently published a systematic review and meta-analysis in the Lancet Psychiatry showing that somatoform disorders are on par, both in prevalence and burden of disability, with common mental disorders such as depression and anxiety.
The researchers quantified the health burden of somatoform disorders in terms of years-lived-with-disability (YLDs), which equated to 662 YLDs for every 100 000 people.
They estimated about 1 in 21 adults globally (4.6%) are living with a somatoform disorder, with prevalence higher among females (7.7%) than males (2.8%).
“It’s on par with common mental disorders that are included in the big mental health surveys worldwide. But somatoform disorders are rarely included,” he said.
A world first
The researchers were the first to quantify somatoform disorders in this way.
“Our review was the first to use GBD inclusion criteria — meaning focusing on diagnosable cases among the entire population, not just primary care or children, and not derived from symptom scales,” said A/Prof Santomauro.
“We were also the first to use available information on its disability, and combine this with our prevalence estimate to calculate non-fatal burden, and compare it directly to other disorders,” he said.
“Our analysis pulls all the information together and calculates a reasonable prevalence estimate. And we estimate about 5% of the population.”
“There had been other efforts to estimate the prevalence of these disorders, but there were big limitations with those studies.”
“Some were focused on specific populations. Some were focused on specific settings, like primary care. Some included symptom scales rather than focusing on the actual diagnosable disorder. Our review was the first to use GBD inclusion criteria for this disorder.”
“I think this is really landmark because of the ranking of this disorder, to be able to say it’s potentially the second most burdensome [mental health disorder] in the world.”
“There are caveats to that. The way we’ve modelled prevalence is different to the way it’s modelled with GBD. GBD uses a much more complicated and sophisticated process and estimates by age and sex, and by country; it’s very granular. For the sake of this proof of concept, we’ve kept it as traditional meta-analysis or meta-regression. It’s a bit cruder, but at least gives a good gauge as to say, is this worth putting into GBD, and then modelling in a more sophisticated manner.”
Stigma and somatoform disorders
A/Prof Santomauro said that somatoform disorders come with stigma, and that may be one cause of their being taken less seriously by the general public.
“It’s been raised by experts a few times to us, who have theorised that somatoform disorders might be more prevalent in locations where mental disorders are not necessarily as accepted, where maybe there’s more taboo,” he said.
“Something I keep hearing is that sometimes when you go outside of the high-income regions, mental disorders can come out instead as chest pain, physical pain. But they end up being caused by mental problems or mental health issues.”
“And so at the moment in the GBD, we estimate higher prevalence of mental disorders in high-income locations. And my hope is that including somatoform disorders may offset some of that disparity, by quantifying some of the burden.”
“But we need more data. For example in sub-Saharan Africa, Latin America, the Caribbean and around the world. Most of that was from high-income countries. That was a big limitation.”
A/Prof Santomauro says that stigma — that somatoform symptoms are ‘all in the head’ — might be at play when it comes to challenges accepting SSRDs.
“You might have experienced firsthand going to a doctor, and having all these symptoms, and they do a whole bunch of investigating but can’t find the cause. But there’s rarely a discussion about a somatoform disorder.”
“It’s probably a very difficult conversation: telling someone that what they’re feeling is psychologically related, because it makes them feel like you’re telling them it’s not real. But what these people are feeling is 100% real.”
“It is a strong pain. It’s severe gastro symptoms. It’s massive migraines. And then there’s the distress that the patient is experiencing, especially if it’s something they can’t find the root cause for.”
“Somatoform disorders have not been a suggestion in the past. I would like it to become something that’s more acknowledged.”
Women have a higher prevalence
The researchers found that somatoform disorders were more than twice as prevalent for females than for males.
“We did estimate high prevalence for females: the estimates were 8% prevalence for females, and nearly 3% for males,” said A/Prof Santomauro.
“We do often see this pattern across almost every other mental disorder. For depressive disorders and anxiety disorders we see a similar pattern,” he said.
“I do think that somatoform disorders would definitely be dismissed more among women.”
“There are those kinds of biases that we have in our society, perceptions that physical or pain complaints from women can be dismissed a bit more than from men. The perception that if men are complaining, it must be ‘really bad.’ If women have these complaints they’re likely going to be dismissed at a greater rate than men.”
A/Prof Santomauro said that the next step is to have somatoform disorders considered for inclusion in the GBD Study so that it can be considered by policy makers and service planners.
“My hope is that once these disorders are included in the GBD Study, they will then be considered by policy makers, service planners, and resource allocators in the future.”
Becca Whitehead is a freelance journalist and health writer. She lives in Naarm and is a regular contributor to the MJA’s InSight+.
Subscribe to the free InSight+ weekly newsletter here. It is available to all readers, not just registered medical practitioners.