The challenges of diagnosis and continuing patient assessment

The adoption of operational diagnostic principles, embodied in the current ICD and DSM methodologies, which are firmly based on the objective assessment of symptoms, has improved the reliability of schizophrenic diagnosis to levels roughly comparable with those of many other medical conditions of unknown aetiology. However, the differences between schizophrenia and the major affective disorders in terms of aetiology, pathology, course and outcome, and treatment response now appear less obvious than perhaps previously considered, bringing the validity of the current dichotomous classification of 'non-organic' psychoses into question. While this is an important area of current debate, it is imperative that present theorizing should not pull psychiatry back into the chaos of conflicting diagnostic ideologies which characterized thinking and practice for much of the 20th century. Despite some differences, the major diagnostic systems, ICD and DSM, have in their principles little to chose between them and can share credit in bringing about advantages that have been hard won. These systems should be used routinely in establishing a diagnosis of schizophrenia in everyday clinical practice. As stated in the Principles of Practice, establishing diagnosis is a key function of the clinician, but it is only one step in the complex process of patient evaluation, and one whose prominence may decline with increasing time and certainty. While the emphasis may vary over time, effective and comprehensive care should incorporate regular multidimensional, 'needs-based' and risk assessments covering a wide range of parameters, ensuring that the effects of variation in the individual patient over time can be understood and put into context in treatment planning. This may be best achieved in the context of a positive, stable and lasting relationship between the psychiatrist and patient. Establishing such a trusting and therapeutic relationship responsive to changing needs that will extend over years, represents both one of the greatest challenges and one of the most rewarding aspects of clinical medicine.