This summary provides background information about the enablers, challenges and impact of integration, based on a thorough literature review of thirty-five sources. The review findings are presented under thematic headings that reflect the: (1) extent of integration: the "stage" or depth of the collaborative activity in integrated services; (2) integration of structures: the supporting organisation and frameworks required at different organisational levels; (3) integration of processes: the actions or operations required at different organisational levels; and (4) reach of integration: the extent to which partnerships in integrated services reach out to include diverse agencies.