Whether you believe we need needs or not, needs assessment has become a driving principle of modern mental health service delivery and underpins care planning. Several operationalised assessment tools exist, but since its introduction in 1995 the Camberwell Assessment of Need (CAN) has rapidly become a research tool of choice and has spawned several specialist versions.

The CAN–M is the latest of these and succeeds in retaining the simple and accessible structure of the original, while managing that rarest of things, adding without over-burdening. This is important, because one of the great strengths of the CAN is its relative brevity. Of course this can be seen as over-simplification of a concept that is much more complicated than it appears on the surface, but it is clear that the authors of the CAN–M have a sophisticated view of this. They specifically caution that the instrument is designed to identify needs and not to describe them in any great detail.

The CAN–M comes in three formats, a clinical, research and short appraisal version. Service users' and professionals' ratings are recorded and scored separately. The instruments are complemented by authoritative summaries of needs assessment in general, the needs of women with mental health problems around childbirth and the needs of severely mentally ill mothers with children, together with an excellent review of the impact of maternal mental illness on the developing child.

The new domains in the CAN–M, developed following a survey of service users and professionals, are relatively predictable and have face validity (for example, there are domains on the emotional and practical demands of childcare). The results of the development survey and an evaluation survey are described.

The authors suggest that formal training in the use of the CAN–M is not necessary, but they provide a training guide together with overheads that can be photocopied onto transparencies. The training guide can be used to develop understanding of needs assessment or to develop interrater reliability among research staff.

For anyone working in the field of mental health, parenting and childcare, the CAN–M will be a useful assessment tool, not just in relation to needs for clinical care, but in relation to needs for social care and support with safeguarding. Risks are clearly related to unmet needs for support with parenting and in these times of high anxiety about safeguarding, the publication of the CAN–M is very timely.