Reliability and validity of the knowledge about Depression and Mania Inventory

Background: The knowledge that patients with affective disorders have about their illness is attributed increasing importance. For a number of psychiatric disorders, the imparting of information about the illness is now standard treatment. However, the relevance of knowledge about a patient's disorder has to date not been sufficiently studied. One reason for that is that only few psychometrically validated instruments for the assessment of illness knowledge exist. The aim of this study was the development and psychometric evaluation of a questionnaire to assess knowledge about affective disorders. Methods: The Knowledge about Depression and Mania Inventory ( KDMI) was evaluated with a sample of 337 patients with major depression, relatives of patients with depression and schizophrenia, and controls. Results: With the 44-item KDMI, the 3 dimensions knowledge of symptoms, knowledge of treatment and knowledge of coping strategies were differentiated. From these 44 items two 22-item parallel tests were developed for follow-up assessment. The scales showed good internal consistency. There were numerous indicators of the validity and sensitivity to change of the scales. It was shown that older patients and patients with lower levels of education are less knowledgeable about affective disorders. There were significant differences in the scales of the KDMI before and after a psychoeducative group for relatives. Conclusions: The study showed that knowledge about affective disorders can be reliably and validly measured by a questionnaire. Because of its brevity the KDMI is suitable for everyday use in clinical practice, and it forms the basis for further investigation of the significance of illness knowledge, as well as for evaluation of the effects of psychotherapy in this area.