Abstract
The frequent association between primary headaches and psychiatric disorders is consistently reported in the literature. There is increasing evidence that a bi-directional relationship links these somatic conditions to psychopathological events. Prospective studies show that several psychiatric disorders are severe risk factors for both the onset and chronicisation of primary headache, and for a long time it has been suspected that headache triggers psychiatric disorders, mostly of affective nature, and affects both their course and outcome. Researchers are actively involved in investigating the biological basis of such a relationship while clinicians still need to strengthen their interest in psychiatric comorbidity of their primary headache patients to improve clinical outcome and to prevent chronic evolutions.