 Participants will be requested to come to the Department of Psychiatry of the University of Oxford for an initial screening assessment including basic medical examination and structured psychiatric interview. On that occasion they will also be asked to complete a number of questionnaires such as Beck Depression Inventory, Dysfunctional Attitudes Scale, State-Trait Anxiety Inventory, Eysenck Personality Questionnaire, Parental Bonding Instruments and Life Events Rating Scale. 