Chronic pain and major depressive disorder in the general population
Introduction
Major depressive disorder (MDD) is one of the most prevalent psychiatric disorders and as such represents a major public health problem in the United States and Western Europe. Community based surveys in the USA have reported a 30-day prevalence of 4.9% (Blazer et al., 1994) and a 12-month prevalence of 6.6% (Kessler et al., 2003). However, MDD rarely occurs alone. In a study of 18,980 subjects, representative of 320 millions of Europeans, we reported that 43.4% of individuals who met criteria for MDD also had a Chronic Painful Physical Condition in contrast to 16.1% of the remaining general population (Ohayon and Schatzberg, 2003). In that study, Chronic Painful Physical Condition (CPPC) was defined as pain present for the last 6 months and resulting in either consulting a physician or taking medication. MDD subjects with CPPC had more severe symptoms of insomnia, fatigue, impaired concentration and psychomotor retardation than did MDD subjects without pain (Ohayon, 2004). Therefore, it was not surprising that physical symptoms were often the main reason cited by subjects with depressive disorders for seeking medical help (Ohayon and Schatzberg, 2003). This has also been observed in primary care settings: up to 69% of patients identified with MDD consulted their physician primarily for physical symptoms (Simon et al., 1999). The association between pain sites and depressive symptomatology has rarely been described in epidemiological studies and often limited to specific types of pain (Magni et al., 1993, Magni et al., 1994, McWilliams et al., 2003). Our previous epidemiological study (Ohayon and Schatzberg, 2003) had a narrow definition of chronic pain that included only those who consulted for pain or who took a medication for pain. Therefore, the segment of individuals with chronic pain who did not consult for pain was absent. Pain often hides the depressive syndrome thus delaying its recognition and treatment.
The objectives of this study were (1) to assess whether chronic pain was associated with differences in depressive symptom patterns in a community sample representative of the California general population; (2) to investigate how the presence of chronic pain affected disability or impairment in depressive individuals; and (3) to examine how the presence of chronic pain influenced the likelihood of receiving treatment.
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Sample
The study was performed in 2003 and 2004. The target population were adults (18 years and older) living in the state of California (USA). This represented 24 million inhabitants. A total of 3243 subjects out of 3787 eligible individuals participated in the survey (participation rate 85.6%).
Procedures
In the first stage, telephone numbers were pulled out proportionally to the population size of each county in California. Telephone numbers were randomly selected within each county using a computerized
Results
The sample included 3243 subjects between 18 and 94 years of age. Women represented 51.2% of the sample.
Discussion
This study examines the association between Chronic Painful Physical Condition (CPPC) and major depressive disorder (MDD) in a community sample of 3243 subjects, representative of the general population of the state of California (24 million inhabitants aged 18 years and older). An overwhelming majority of subjects who meet criteria for MDD also reported CPPC (73.3%).
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In our earlier study (Ohayon and Schatzberg, 2003), we used a shorter questionnaire on pain, and the analyses were limited to
Contributors
M.M.O. had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. He is the principal investigator for this study. As such, he designed the protocol and supervised the data collection. He participated in the data analyses strategies, interpretation of data and writing of the manuscript.
Dr. Schatzberg participated in the data analyses strategies, interpretation of data and writing of the manuscript.
Role of funding sources
The sponsors had no role in the design and conduct of the study (collection, management, analysis) nor in the interpretation of the data. The sponsors have not seen the manuscript. M.M.O. had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Conflict of interest
Dr. Schatzberg has in the past been a paid consultant for Eli Lilly, Wyeth, Pfizer, and Forest Laboratories and has equity in Pfizer and Forest Laboratories.
Acknowledgements
This study was supported by the Arrillaga Foundation (M.M.O.) and an unrestricted educational grant from Eli Lilly (M.M.O.).
References (42)
- et al.
Prevalence, onset and risk of psychiatric disorders in men with chronic low back pain: a controlled study
Pain
(1991) - et al.
Psycho socio-biological correlates of moderate overweight in an industrial population
Journal of Psychosomatic Research
(1978) - et al.
Chronic musculoskeletal pain and depressive symptoms in the national health and nutrition examination. I. Epidemiologic follow-up study
Pain
(1993) - et al.
Prospective study on the relationship between depressive symptoms and chronic musculoskeletal pain
Pain
(1994) - et al.
Mood and anxiety disorders associated with chronic pain: an examination in a nationally representative sample
Pain
(2003) - et al.
Depression and anxiety associated with three pain conditions: results from a nationally representative sample
Pain
(2004) Improving decision-making processes with the fuzzy logic approach in the epidemiology of sleep disorders
Journal of Psychosomatic Research
(1999)- et al.
Depressive symptoms in overweight and obese older adults: a test of the jolly fat hypothesis
Journal of Psychosomatic Research
(1996) - et al.
Population-based survey of pain in the United States: differences among white, African American, and Hispanic subjects
The Journal of Pain
(2004) - et al.
Prevalence of chronic benign pain disorder among adults: a review of the literature
Pain
(1998)