Primary headache disorders are among the most prevalent conditions affecting various populations worldwide. Personality traits and psychiatric disorders are important comorbid and possibly causal conditions in migraine and mediators of stress impact on migraine or tension-type headache. These include neuroticism, anxiety, panic disorder, depression, and post-traumatic stress disorders. Post-traumatic stress disorder (PTSD) is a well-recognized risk for and modulator of headache. Peterlin and colleagues evaluate the relative frequency of PTSD in episodic migraine (EM), chronic daily headache (CDH), and the impact on headache-related disability. The goal of behavioral management for stress must be to improve headache frequency and severity and to improve quality of life by increasing patient self-knowledge, disease knowledge, and sense of control and self-efficacy. The role of stress as a modifier or trigger of headache should be actively evaluated in all patients with recurrent or chronic headache disorders.