The definition of community psychiatry and related terms is attempted by reference to various authors in the field. The development of the concepts of community psychiatry in relationship to state psychiatric services is outlined.

The essentially practical approach of relating services to community need is derived from epidemiological studies and from socio-cultural studies of the communities to be served. The need for new techniques in treatment and the mobilisation of a variety of professional and social resources forces the clinical psychiatrist into a wider frame of reference.