To explore the relationship between chronic tension-type headache (CTTH) and psychological factors (personality traits and psychological distress) in a population-based sample and to determine the influence of headache frequency and medication days. An age- and sex-stratified random sample of 30,000 persons aged 30-44 years from the general population received a mailed questionnaire. Those with a self-reported chronic headache were interviewed by neurological residents. The questionnaire response rate was 71%, and the rate of participation in the interview was 74%. The International Classification of Headache Disorders was used. Personality traits were assessed by the Eysenck Personality Questionnaire (EPQ), neuroticism and lie scale, and level of psychological distress, by the Hopkins Symptom Checklist-25 (HSCL-25). For comparison, cross-sectional data from the Danish and the Norwegian general population using the same instruments were used. Persons with CTTH had a significantly higher neuroticism score and a significantly higher level of psychological distress than the general population. Headache- or medication days per month had no significant influence on the neuroticism- and lie scores or the HSCL-25 score. Persons with CTTH have a high level of neuroticism and psychological distress. This can be either a primary or a secondary effect related to the premorbid psyche or caused by the chronic pain and is a question that future studies should address. © 2011 John Wiley & Sons A/S.
