International Study Finds Back Pain and Mental Health Closely Tied
Commentary by Michael R. Clark, MD, MPH, MBA
Back pain appears to be a common ailment all over the world, and oftentimes, it co-occurs with mental health issues.
In a new study published in General Hospital Psychiatry,1 researchers found many countries with predominantly people in the low to middle income range suffer from back pain and chronic back pain much in the same way as people in more developed higher income nations.
These people also report suffering from various mental health issues, including anxiety, depression, stress sensitivity, sleep problems, and psychosis—mental health issues that seem to have an intrinsic relationship with back pain symptoms.
How Back Pain and Mental Health Interrelate
Many studies have explored the possible relationship between back pain and mental health problems. However, the scarcity of epidemiological data from less-developed nations has prevented doctors from better understanding how back pain and mental health could affect a much larger, multinational population of patients.
In this new study, a massive epidemiological undertaking called the World Health Survey (WHS) organized a cross-sectional, community-based initiative, culling together data on 190,593 adults from all corners of the world. Forty-three low-middle-income countries (LMIC) were included in the study group, some of which included:
Adults (≥18 years) were asked if they experienced back pain within the last 30 days. If they had experienced back pain for every 1 of the 30 days, they were reported as having chronic back pain. To determine the types of depressive symptoms found in patients, the WHS incorporated its own version of the Mental Health Composite International Diagnostic Interview (CIDI).2-3 Patients also were asked questions to determine if they had experienced various mental health issues, including:
- Sleep problems
- Psychosis (delusional and hallucinatory experiences)
- Stress sensitivity
Out of 190,593 adults (mean age 38.4; 50.7% female), back pain was a prevalent: 35.1% of patients reported any type of back pain, and 6.9% had chronic back pain. Researchers also found that a number of patient characteristics were related to back pain, including:
- Older age
- Female sex
- Low income
- Low education
- Urban setting
- Current smoker
- Alcohol consumption
But perhaps the most telling trend in the data was how often mental health issues were associated with pain. If patients had any type of depression or psychosis, anxiety, or sleeping problems, there was a much higher prevalence of some form of back pain or chronic back pain. In fact, all types of mental ailments were associated with >2 x higher odds for developing some type of back pain.
Stress appeared to be another major factor for patients. The higher the severity of stress sensitivity, the more linear an increase in the prevalence of both forms of back pain. Depression also showed a strong connection to back pain, particularly to chronic back pain.
For years, researchers have explored the notion that back pain can influence mental health, and vice versa. But according to the authors of the current study, this new evidence adds substantial epidemiological evidence to the discussion. By mapping patient characteristics concerning back pain and mental health within the context of a multinational, multiracial cohort, the study presented some novel findings.
For instance, depression and back pain have long been considered bidirectional, particularly in studies examining Western populations.4-5 However, this new study triaged patients with different points in the depression spectrum, including subsyndromal depression and brief depressive episodes. Doctors could see how, regardless of the level of depressive symptoms, depression and back pain showed a high comorbidity rate, something which could be indicative of an “underlying shared pathophysiology,” the authors wrote.
Researchers also found patients with psychotic disorder (including schizophrenia) had 2.05 and a 2.68 times higher odds of suffering from back pain and chronic back pain, respectively.
The quality of the epidemiological data perhaps benefits from its impressive sample size. However, this could also be to its detriment, according to Practical Pain Management editorial board member Michael R. Clark, MD, MPH, MBA, director of the pain treatment program at Johns Hopkins University in Baltimore, Maryland.
“At one level, this is a large epidemiological study across different countries, which is better than the small sample sizes that plague some of this research. At another level, the numbers are so large that they have the power to find statistical relationships between multiple variables, which are usually poorly defined,” Dr. Clark explained.
Indeed, the study authors noted that while CIDI definitions for depression diagnosis are widely accepted throughout the world, it is still somewhat uncertain the validity of diagnosis criteria is maintained in more low-median income countries, especially if those countries suffer from a lack health care provisions and training.
Furthermore, the study is cross-sectional in design, which precludes any conclusions being drawn about how back pain and mental health disorders relate to one another. Although, a “dose-response” pattern, where worse back pain was associated with mental health disorders, could have been significant, the authors noted.
“This study extends our understanding of what we already know about the relationships between pain syndromes such as BP/CBP and depression,” Dr. Clark told Practical Pain Management. “These relationships are important at many levels. From a public health standpoint, we need to design more aggressive early interventions for patients with pain to identify and treat these psychiatric disorders to prevent long-term disability and high utilization of healthcare resources.
“At the patient level, practitioners need to be alert for patients with high levels or long duration of pain as being at risk for psychiatric disorders that deserve treatment independent of therapies for pain but should be incorporated into all forms of interdisciplinary pain management,” said Dr. Clark.
Study lead author Brendan Stubbs, MD, received funding National Institute for Health Research Collaboration for Leadership in Applied Health Research & Care Funding scheme. The authors declared no conflicts of interest.