Patients with cluster headaches--severe headaches occurring in clusters of several months and then receding--have a higher rate of anxiety disorders during the time between clusters of headaches and show memory deficits during headache clusters, according to a recent University of Iowa Health Care study.

Ricardo Jorge, MD, associate research scientist in the UI Department of Psychiatry and lead author of the study, said the impetus for the study was a previously identified link between migraines and depression and anxiety. Cluster headaches, similar to migraines in many ways, were thought to have a similar link, increasing the likelihood of patients getting mood and anxiety disorders.

"If cluster headaches occur frequently with anxiety, the headaches may cause the anxiety or the other way around," Jorge said. "It is important to know the relationship between them so that doctors may treat patients better."

Cluster headaches' intense pain lasts 15 minutes to an hour. This pain usually occurs over periods that last a few months. After this time with multiple and severe attacks, the headaches disappear for a long length of time and then begin again without warning.

The causes of cluster headaches are unknown, but some evidence suggests changes in blood flow in the brain and dysfunction in certain brain areas. The incidence of cluster headaches is low, and cluster headaches affect more men than women, at a ratio of as many as seven to one. These figures may be somewhat misleading; doctors are increasingly diagnosing cluster headaches in women, Jorge noted.

The association of cluster headaches and anxiety disorders may also be related to brain dysfunction, especially certain areas known to be involved in the development of mood and anxiety disorders, according to the researchers.

There is no universal treatment for cluster headaches, Jorge said, although many treatments may be divided into managing the headache attack or decreasing the number of attacks during a cluster. Oxygen is often used to alleviate the pain as it happens, while other medications, including lithium, are used to reduce the length of an episode.

While there may be a link between cluster headaches and anxiety disorders, more work should be done before attempting to decide how best to treat patients with both or who are likely to contract both, Jorge noted.

"We need a bigger sample and then we will try to replicate our findings. Then maybe we can see if any specific type of treatment or approach is needed for those patients with cluster headaches and anxiety disorders. We also need to further research the significance of the memory disturbance involved with these headaches," Jorge said.