Objective: That anxiety disorders are more prevalent among women than men , has been suggested through previous studies. Our purpose is to determine which factors cause this effect. Metacognitive factors that can explain the causes of more prevalent anxiety. Methods: This Study is conducted with the high school girls and boys who have been affected by Generalized Anxiety Disorder (GAD). GAD is a chronic condition centrally defined in DSM IV as excessive anxiety and subjectively uncontrollable worry in the presence of at least three somatic symptoms which have persisted for at least six months. The sample consists of 100 high school students (50 boys and 50 girls ) that have been selected by Generalized Anxiety Disorder Scale (GADS) and semi-structured interview. Instruments : Metacognitive Thought Control Questionnaire (TCQ) , GADS and Anxiety Thoughts Inventory (AnTI). Results : Significant differences between girls and boys in anxiety thought (health anxiety, social anxiety, and metaworry). Anxiety thoughts affect girls more than boys, as well as they have more metacognitive beliefs about uncontrollability of worry and believe that they must avoid worry. Also girls have positive beliefs about worry more than boys and also using punishment and metaworry as control strategies is higher in girls. Conclusions: Girls are more affected by anxiety, because of their metacognitive beliefs about uncontrollability , advantages and avoidance of worry.
