Generalized anxiety disorder, subthreshold anxiety and anxiety symptoms in primary headache.

AIMS: The aim of the present study was to evaluate the association between generalized anxiety disorder, subthreshold anxiety (SubAnx) and anxiety symptoms in the prevalence of primary headache. METHODS: This cross-sectional study evaluated 383 people from a Brazilian low-income community. One-year prevalence rates of migraine, chronic migraine and tension-type headache were calculated. Anxiety symptoms were then separated into the following groups (based on DSM-IV criteria): no anxiety criteria; one anxiety criterion; two anxiety criteria; and generalized anxiety disorder (GAD). The control group (no headaches) was compared with headache sufferers for each anxiety group using an adjusted model controlled for confounding factors. RESULTS: GAD was present in 37.0% of participants and SubAnx in 16.6%. Those with SubAnx had a 2.28-fold increased chance of having migraine; 3.83-fold increased chance of having chronic migraine, a 5.94-fold increased chance of having tension-type headache and a 3.27-fold increased chance of having overall headache. Some anxiety criteria (irritability, difficulty with sleep, concentration problems, muscle tension and fatigue) had similar prevalence to International Classification of Headache Disorders (ICHD-II) headache criteria such as unilateral pain and nausea for migraine and chronic migraine. CONCLUSION: Headache sufferers seem to have a high prevalence of anxiety symptoms and SubAnx. In addition, the presence of two or more anxiety criteria (not necessarily fulfilling all the criteria for GAD) was associated with having a headache disorder.