This book provides a needs-based assessment specifically designed for use with pregnant women and mothers with severe mental illness (SMI). It is a practical manual providing an introduction to the topic of needs assessment, plus sections on the development of and guidance for usage of the CAN-M scales. It includes different versions of the ratings scale for research purposes, for clinical purposes, and a short version which can be used more quickly for either. It describes the fourth variant of Gaskell’s CAN: Camberwell Assessment of Need (Slade et al., 1999) which is the most widely used needs assessment instrument in the UK and Europe.