On the basis of the criteria of the International Headache Society (IHS) tension-type headache (TTH) is classed among the primary headaches. The independent headache diseases are characterized with the type of headache and with the concomitant symptoms. Among the independent headaches TTH has the highest prevalence (38.3%). The prevalence which is the highest between the age of 30 and 39, in women is higher (46,9%) than is men (42.3%). The diagnosis of TTH is not automatically mean the diagnosis of depression. Depression can occur as a comorbid disease. In episodic TTH the prevalence of depression is 32%, while in chronic TTH it is 40%. The prophylactic treatment of patients suffering from chronic TTH has not been solved yet. On the basis of a double-blind, placebo-controlled study mirtazapine is said to be a good opportunity in the treatment of patients with chronic TTH, as it improved the status of the patients with 34% (AUC: Area Under the headache Curve calculated from the product of the period and the intensity of headache), moreover mirtazapine decreased the frequency, intensity and duration of headache as well. The favourable effects of mirtazapine is explained beyond its serotonergic and noradrenergic dual mode of action with its antinociceptive effects which is presumably fulfilled via 3-opioid receptors.