The World Health Organization (WHO) conducted a study to collect data on mental health resources of pilot areas within several European countries. This report presents data from the study and provides a detailed and reliable description of the development of mental health services within the WHO European Region. Part I of the report describes the study and the use of data in seven chapters: (1) "From Phases I and II to Phase III" (R. Giel and J.U. Hannibal); (2) "Mental health information systems" (A. Dupont); (3) "Use of social and demographic data in the planning and evaluation of mental health services" (G. Moschel); (4) "Mental health services models in Europe" (D. Walsh); (5) "Patterns of care and service utilization" (R. Giel, et al.); (6) "The relationship between social conditions, service models and patterns of care" (N. J. Lavik); and (7) "The pilot areas study and the context of mental health care" (H.L. Freeman and T. Fryers). Part II contains an introduction by J.U. Hannibal and G.H.M.M. ten Horn and area descriptions from Austria (Mistelbach); Belgium (Brussels, Leuven); Denmark (Randers); Finland (Tampere); France (Paris 7, Paris 13); West Germany (Mannheim); Greece (Athens); Ireland (Dublin); Italy (Trieste); Netherlands (Groningen); Norway (Oslo); Romania (Iasi); Spain (El Ferrol, Leganes); Switzerland (Geneva); United Kingdom (Aberdeen, Nottingham); and Yugoslavia (Belgrade, Zagreb). An annex contains instructions and data sheets for the cohort study. Tables and figures are included. (NB)