This thesis is submitted in partial fulfilment of the requirement of the Degree for Doctor of Clinical Psychology at the School of Psychology, University of Birmingham. It comprises clinical work and research involved conducted throughout the duration of the course. Volume I of the thesis is presented in the form of three papers examining potential risk markers of early psychosis; impaired neuropsychological performance and dermatoglyphic anomalies. The first of the three papers is an empirical study that examines the neuropsychological performance in a group of participants, considered to be at ultra-high risk of psychosis, and compares it with that demonstrated by a control group. This paper is prepared for submission to the British Journal of Psychiatry. The second paper is a systematic literature review which examines the literature on dermatoglyphic anomalies associated with schizophrenia. This paper is prepared for submission to the British Journal of Psychiatry. The third paper is an executive summary that has been used to disseminate the main findings of this research to participants and health care professionals. The appendices contain correspondence regarding instructions for authors, ethical approval, assessment instructions, information sheets and consent forms. Volume II of the thesis contains five clinical practice reports that were submitted throughout the course. These reflect the training performed and the clinical work conducted. Clinical practice report one, models on adult placement: 'Formulating the case of a 55-year old woman with obsessive compulsive disorder: Psychodynamic and cognitive perspectives'. Clinical practice report two, small-scale service evaluation on child placement: 'Evaluating User Satisfaction of a Mental Health Drop In Service '. Clinical practice report three, case study on older adult placement: 'A cognitive-behaviouralformulation and intervention for a 67 year old woman with agoraphobia' and clinical practice report four, single-case experimental design on learning disabilities placement: 'A cognitive-behavioural intervention for a 49 year old gentleman with anger-related difficulties ', Clinical practice report five, the abstract for an oral presentation of a case study on specialist forensic placement: 'Cognitive formulation of a 20-year old Sikh male, charged with affray'. All names and identifying details in these reports have been changed to ensure confidentiality.