Psychiatric issues are prominent among patients with more difficult headache problems, particularly chronic daily headache. Patients with chronic daily headache often present with a sense of emptiness, sadness and pain that may be visible even in their facial expressions. These symptoms might be common to both migraine and psychiatric disorders (American Psychiatric Association, 1995; Blumenthal and Rapoport, 2001), as shown in the Table.
Since transformed migraine, the most common form of chronic daily headache, evolves from migraine, one would expect a similar profile of psychiatric comorbidity. Studies have shown that depression occurs in 80% of patients with transformed migraine (Juang et al., 2000). The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) was found to be abnormal in up to 61% of patients with primary chronic daily headache, compared with 12.2% of patients with episodic migraine (Cerbo et al., 2000; D'Amico et al., 2000; De Fidio et al., 2000). Comorbid depression often improved when the pain returned to episodic patterns.
A recent multicenter study was carried out in 10 Italian headache centers to investigate the prevalence of anxiety and depression in patients with chronic daily headache (De Fidio et al., 2000). The study investigated 219 patients. The results showed that anxiety and depression levels, in each group, were related to gender (females>males). Anxiety, but not depression, was related to the length of the chronification process. Anxiety and depression did not correlate with type of headache at onset. They concluded that chronification is a biological and psychological trait. The same group reported a triggering role of stress on the chronification process, suggesting that patients with transformed headache are characterized by a different way of reacting to stress.
Stewart et al. (2001) also suggested that stress, particularly environmental factors, may play a role on the pathophysiological mechanisms of chronic daily headache. They found that specific stressful life events, such as divorce, widowhood, separation and problems with children, were more likely to be associated with increased prevalence when compared to controls. The assessment of psychopathology in patients with chronic daily headache showed characteristic profiles of hypochondria, depression and hysteria scales of the revised version of the MMPI-2 (De Fidio et al., 2000).Figure 3> depicts possibilities for headache and psychiatric comorbidity, depending upon presence of disorders in Axis I to Axis III of the DSM-IV-PC. The left column shows headache accompanied by no Axis I or Axis II disorders. Treatment is very straightforward and only the headache with medication overuse, if present, must be treated. In the center column, headache is accompanied by major depression, but no Axis II disorder. Treatment is more complex but outcomes are fairly good with proper recognition and treatment of both conditions. In the right column, there are disorders on all three Axes, and the patient's treatment is most difficult with a less favorable prognosis. As one moves from left to right, patient's treatment becomes more complex and more challenging, showing the importance of recognizing the psychiatric comorbidity in such cases. Patients with disorders on all three axes with chronic daily headache and medication overuse (both over-the-counter and prescription analgesics, including mixed butalbital compounds, opiates/opioids and others) generally require intensive multidisciplinary treatment, including inpatient treatment. The latter treatment is generally best done on specialized headache units with pharmacologic and nonpharmacologic protocols.
A relationship to alcohol(Drug information on alcohol) overuse, illicit drug use and chronic daily headache was reported by Mathew et al. (1982). They also reported the high frequency of sleep disturbances among patients with chronic daily headache.
Poor sleep is the most common complaint of many chronic daily headache sufferers. Drake et al. (1990) recorded nocturnal sleep in 10 patients with common migraine, 10 individuals with tension-type headache and 10 patients with chronic daily headache. Chronic daily headache was associated with reduced sleep, increased awakening, diminished slow-wave sleep, and rapid eye movement sleep that was decreased in amount and reduced in latency.
We recently conducted two studies assessing psychiatric comorbidities in several headache subgroups. In the first study, our sample consisted of 638 patients with chronic daily headache, broken down to 558 with transformed migraine, 69 with new daily persistent headache (i.e., sudden onset of chronic headache in the absence of secondary causes), six with chronic tension-type headache and five with hemicrania continua. We also studied 65 patients with chronic posttraumatic headache. Our control group consisted of 100 patients with episodic migraine (Bigal et al., 2002). We found the following positive associations between habits, comorbidity and chronic daily headache.
Habits. Patients with chronic daily headache have statistically significant higher levels of alcohol consumption. The highest level was observed in the new daily persistent headache group (p<0.01 against the other chronic daily headaches). A higher number of patients with chronic daily headache had the habit of smoking (p<0.05).
Self-evaluation of depressive symptoms. Patients with chronic daily headache felt depressed more frequently than migraine patients.
Self-evaluation of anxiety symptoms. All chronic daily headache groups reported higher levels of anxiety when compared to migraine patients (p<0.01).
Sleep profile. Patients with chronic daily headache had several sleep problems, contrasted with those with episodic headache, as shown in Figure 4. Overall, patients with chronic daily headache did not feel that they sleep well nor did they feel rested in the morning. Interestingly, patients with new daily persistent headache have a sleep profile similar to migraine and different from the other chronic daily headaches.
In the second study, we assessed the psychological profile of a large sample of patients with chronic daily headache seen in tertiary care (Bigal et al., 2003). We used a case-control design to study a group of 791 patients who fell into the following categories:
These groups were compared to two control groups:
All patients had their personality and psychopathology assessed by the MMPI-2. The occurrence of t-scores ≥65 and œ40 were analyzed by the two-sided Fischer's exact test. Analgesic-rebound headache and chronic migraine patient groups had a higher number of subjects with t-scores ≥65, when compared to the migraine group and when analyzing the following scales: scale 1 (hypochondrias), scale 2 (depression), scale 8 (schizophrenia) and scale 0 (social introversion). No differences were observed when comparing the new daily persistent headache and migraine groups. We concluded that:
Comorbidity is certainly a common finding in patients with migraine and other chronic headache syndromes. As with many other lifelong illnesses, conditions that control migraine and chronic daily headache are multidimensional, involving cognitive/emotional factors as well as biologic processes. The correct understanding of this mechanism, including the well-done assessment of the comorbid conditions presented by such patients, is key to implementing more effective interdisciplinary treatment. Intensity of treatment varies in terms of the complexity of illness, ranging all the way from intermittent migraine with no comorbidity to chronic daily headache with multiple comorbidities and medication overuse.