Anxiety disorders linked to thyroid disease, respiratory disease, arthritis and migraine headaches

Anxiety disorders appear to be independently associated with several physical conditions, including thyroid disease, respiratory disease, arthritis and migraine headaches, according to a report in the October 23 issue of Archives of Internal Medicine. This co-occurrence of disorders may significantly increase the risk of disability and negatively affect quality of life.

Although depression has long been linked to physical illness, evidence supporting an association between anxiety disorders and physical health problems is more recent, according to background information in the article. Anxiety disorders include panic disorder, agoraphobia (fear of being in a situation where panic or anxiety may occur and escape from the situation might be difficult), social phobia and obsessive-compulsive disorder. Studies have found that those with phobic (fearful) anxiety may be more likely to experience sudden cardiac death, and rates of anxiety disorders are higher than expected in patients with thyroid disease, cancer, hypertension and several other conditions.

Jitender Sareen, B.Sc., M.D., F.R.C.P.C., University of Manitoba, Winnipeg, Canada, and colleagues further explored the association between anxiety disorders and physical conditions in 4,181 adults who were part of the German Health Survey (GHS), conducted between 1997 and 1999. The survey assessed whether participants had any physical illnesses through a questionnaire asking about 44 particular conditions, a medical interview conducted by a primary care physician, blood pressure measurements and blood and urine samples. Psychiatric interviews were conducted by a psychologist or physician, who used criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) to detect anxiety disorders. A quality of life survey--which measured factors such as physical functioning, pain and general health--was also administered, and to determine disability levels participants reported how many days of the past 30 they were unable to perform their usual daily activities.

Among the 1,913 men and 2,268 women in the study, 429 (8.4 percent) had an anxiety disorder within the past month and 2,610 (60.8 percent) had a physical condition within the past month. Having an anxiety disorder was associated with having any type of physical condition, and specifically with respiratory diseases, gastrointestinal diseases, arthritis, allergies, thyroid diseases and migraine headaches. Most individuals with both an anxiety disorder and physical illness developed the anxiety disorder first, and tended to have a poorer quality of life than those with anxiety disorders or physical conditions alone. Those who had both types of disorders also were more likely to have one or more days of disability than those with physical illnesses alone.

"The mechanisms of association between anxiety disorders and physical conditions remain unknown, although several possibilities should be considered," the authors write. For example, the presence of an illness may cause worry and anxiety that eventually becomes serious enough to qualify as an anxiety disorder, the presence of an anxiety disorders could trigger biological processes that contribute to illness or a third condition, such as a substance abuse disorder, could be linked to both.

"These findings extend previous work in clinical and community samples that noted an association between anxiety disorders and physical illnesses but also demonstrate the unique association of this comorbidity with poor quality of life and disability," the authors write. "Although there have been increased efforts to recognize and treat depression in the medically ill, our findings underscore the need to create similar programs to recognize and treat anxiety disorders in the medically ill."