Physical and mental comorbidity of headache in a nationally representative sample of US adults.

Objective: To investigate the contribution of comorbidity to health utilization and negative health perception in a large-scale population-based study. Comorbidity of headache with physical and mental disorders has been reported frequently in clinical samples.

Methods: This concern was addressed using combined 6-year data from the 1999 to 2004 National Health Examination and Nutrition Survey (n = 31,126 adults), nationally representative datasets of the US population. Measures of physical disorders were based on standardized interviews of chronic conditions, and mental disorders were assessed by the Composite International Diagnostic Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition.

Results: The 3-month prevalence of severe headaches or migraine in the US general population was 22.73%, with females and young adults having greater rates than males and older adults. Adults with headache had increased odds for a variety of physical disorders (including asthma, rheumatoid arthritis, and stroke) and mental disorders (including depression, generalized anxiety disorder, and panic disorder). Adults with headache were more likely to rate their health as "fair or poor" (17.9% versus 6.1%), to seek health care four or more times in a year (43.3% versus 22.7%), and to endorse physical and mental limitations. Health utilization and negative health perception were more strongly influenced by comorbid mental disorders than physical disorders.

Conclusions: The results from this nationally representative sample provide new information on the interrelationships of headache with mental and physical disorders. The greater impact of comorbid mental compared with physical disorders on healthcare utilization and health perception has important implications for the clinical evaluation and treatment of headache in the population.