BT for problems such as OCD requires a level of cognitive flexibility (that is the ability to take a different perspective on ones problems). It could be argued that problems in set shifting (by neuropsychological tests) might underpin problems in this area. Two assessments were used (1: perception of cognitive flexibility was assessed by questionnaire 2: neuropsychological evaluation of set shifting). This study will recruit three groups: OCD patients, anxious and healthy controls. Cognitive flexibility is measured using modified version of the Cognitive Flexibility Scale (Martin & Rubin, 1995) and neuropsychological measures of cognitive flexibility (Wisconsin Cart Sorting Test, Trail Making Test A/B, The Brixton Test). IN addition to the group comparison, the relationship between perceived flexibility, set shifting and psychopathology will be investigated. The implications of the findings for treatment will be investigated.