In Britain we have traditionally bemoaned the lack of accurate, comprehensive, mental health statistics. With the inherent problems of psychiatric diagnosis, the impossibility of defining abnormal in the absence of satisfactory standards of normality, and the diffuseness and variety of agencies that offer help, this lack is neither surprising nor reprehensible. It does, however, make planning difficult. In recent years much progress has been made; and some gaps have been filled, not least by the psychiatric case registers, which have now provided at least a series of base-line statistical descriptions of the use of mental health services and offered opportunities for more effective evaluation (Wing & Hailey, 1972). The statistical descriptions themselves are not enough, of course; but even with very simple figures, questions relatingto social phenomena may be clarified and raised into prominence as important and susceptible to the attentions of both administrators and clinicians. Such statistics are greatly multiplied in usefulness, and general lessons may be learned, if several registers can produce comparable figures. This has recently been done by the Camberwell and Salford registers (Wing & Fryers, 1976). Both these areas are entirely urban and within large conurbations, Camberwell in S. E. London and Salford in Greater Manchester. The Camberwell service focuses on the Maudsley Hospital and has relatively high provision in most respects, but the Salford service can reasonably be considered fairly representative of psychiatric provision in urban England. This paper presents statistical data from studies in Salford, with some comparative data from the Camberwell register, which