RESUMEN
The objectives of the study were: [i] To assess the frequency of different chronic daily headaches in patients using ICHD-2 criteria [ii] To find out the frequency and type of medication overuse and psychiatric morbidity in chronic daily headache subjects. Cross sectional observational study. The study was conducted in the psychiatry outpatient department of a teaching medical institution during January to September 2005. Subjects suffering from chronic daily headache were recruited from a specialized headache clinic in a tertiary care hospital's Psychiatry department. The diagnoses were made according to ICHD-2. Medication overuse was defined according to ICHD-2 criteria and psychiatric illness was diagnosed following ICD-10 criteria in CDH patients. In subjects fulfilling the criteria for 'medication overuse', the culprit drug was stopped immediately and prophylactic therapy was started. Frequency of chronic daily headache was 37% in this sample. Females outnumbered males [1:1.52] and formed higher number of migraine cases [p=0.02]. Tension Type Headache [TTH] was most frequent headache [48.5%]. According to ICHD-2 criteria, probable medication overuse headache could be diagnosed in all patients, which precluded the diagnosis of chronic migraine and chronic TTH. Psychiatric morbidity was seen in 70.3% subjects and mild to moderate depression was the most common illness [53%]. TTH subjects showed predisposition for anxiety disorders [OR= 6.41; p= 0.004]. TTH is the most common subtype of CDH when ICHD-2 is followed. Medication overuse is common in this group of patients and these probably should be discontinued according to substance dependence de-addiction model for better compliance, and even more slowly in subjects with chronic migraine headache. Psychiatric morbidity is prevalent in CDH patients and requires special attention