Feeling bad in more ways than one : Comorbidity patterns of medically unexplained and psychiatric conditions

• Published in: Journal of general internal medicine : JGIM 2007-06, Vol.22 (6), p.818-821
• Main Authors: SCHUR, Ellen A, AFARI, Niloofar, FURBERG, Helena, OLARTE, Megan, GOLDBERG, Jack, SULLIVAN, Patrick F, BUCHWALD, Dedra
• Format: Article
• Language: English
• Subjects: Adult; Back pain; Biological and medical sciences; Chronic Disease - epidemiology; Chronic fatigue syndrome; Comorbidity; Cross-Sectional Studies; Depressive Disorder, Major - diagnosis; Depressive Disorder, Major - epidemiology; Diseases in Twins; Diseases of the osteoarticular system; Fatigue Syndrome, Chronic - diagnosis; Fatigue Syndrome, Chronic - epidemiology; Female; Fibromyalgia; Fibromyalgia - diagnosis; Fibromyalgia - epidemiology; General aspects; Humans; Internal medicine; Irritable Bowel Syndrome - diagnosis; Irritable Bowel Syndrome - epidemiology; Low Back Pain - diagnosis; Low Back Pain - epidemiology; Male; Medical sciences; Mental depression; Mental Disorders - diagnosis; Mental Disorders - epidemiology; Middle Aged; Miscellaneous; Miscellaneous. Osteoarticular involvement in other diseases; Original; Panic Disorder - diagnosis; Panic Disorder - epidemiology; Primary care; Public health. Hygiene; Public health. Hygiene-occupational medicine; Stress Disorders, Post-Traumatic - diagnosis; Stress Disorders, Post-Traumatic - epidemiology; Temporomandibular Joint Disorders - diagnosis; Temporomandibular Joint Disorders - epidemiology; Tension-Type Headache - diagnosis; Tension-Type Headache - epidemiology
• ISSN: 0884-8734; 1525-1497
• DOI: 10.1007/s11606-007-0140-5

Considerable overlap in symptoms and disease comorbidity has been noted among medically unexplained and psychiatric conditions seen in the primary care setting, such as chronic fatigue syndrome, low back pain, irritable bowel syndrome, chronic tension headache, fibromyalgia, temporomandibular joint disorder, major depression, panic attacks, and posttraumatic stress disorder. To examine interrelationships among these 9 conditions. Using data from a cross-sectional survey, we described associations and used latent class analysis to investigate complex interrelationships. 3,982 twins from the University of Washington Twin Registry. Twins self-reported a doctor's diagnosis of the conditions. Comorbidity among these 9 conditions far exceeded chance expectations; 31 of 36 associations were significant. Latent class analysis yielded a 4-class solution. Class I (2% prevalence) had high frequencies of each of the 9 conditions. Class II (8% prevalence) had high proportions of multiple psychiatric diagnoses. Class III (17% prevalence) participants reported high proportions of depression, low back pain, and headache. Participants in class IV (73% prevalence) were generally healthy. Class I participants had the poorest markers of health status. These results support theories suggesting that medically unexplained conditions share a common etiology. Understanding patterns of comorbidity can help clinicians care for challenging patients.