Sources: Medical literature published in any language since 1966 on olanzapine, identified using AdisBase (a proprietary database of Adis International, Auckland, New Zealand) and Medline. Additional references were identified from the reference lists of published articles. Bibliographical information, including contributory unpublished data, was also requested from the company developing the drug. Search strategy: AdisBase search terms were 'olanzapine' or 'schizophrenia' and ('health-economics' or 'pharmacoepidemiology' or 'prescribing' or 'hospitalisation' or 'formularies' or 'drug-utilisation' or 'meta-analysis' or 'therapeutic-substitution' or 'epidemiology'), or 'olanzapine' and 'schizophrenia', Medline search terms were 'olanzapine' or 'schizophrenia' and ('economics' or 'health-policy' or 'quality-of-life' or 'models-statistical' or 'health-planning' or 'epidemiology' or 'guideline in pt' or 'practice-guidelines in pt'. Searches were last updated 26 April 1999, Selection: Economic and quality-of-life analyses in patients with schizophrenia or related psychotic disorders who received olanzapine. inclusion of studies was based mainly on the methods section of the trials. Relevant background data on epidemiology, cost of illness and therapeutic use of olanzapine are also included.