These guidelines from NICE set out clear recommendations, based on the best available evidence, for health care professionals on how to work with and implement physical, psychological and service-level interventions for people with various mental health conditions. The book contains the full guidelines that cannot be obtained in print anywhere else. It brings together all of the evidence that led to the recommendations made, detailed explanations of the methodology behind their preparation, plus an overview of the condition covering detection, diagnosis and assessment, and the full range of treatment and care approaches.The accompanying free CD-ROM contains all the data used as evidence. Autism is a lifelong condition with particular issues for adults, which are addressed by this NICE guideline. While some people are diagnosed in childhood, a large proportion of adults with autism find obtaining a diagnosis in adulthood difficult or impossible. Under-recognition of autism in adults can lead to inadequate care, masking of coexisting mental and physical health problems, and to social and economic exclusion. This guideline aims to address these widespread problems and increase the uptake of interventions by adults with autism to enable them to live more independent lives.This guideline reviews the evidence for care of adults with autism across the care pathway, from identification, assessment and diagnosis, to organisation, delivery and settings for care, through to psychosocial interventions and biomedical interventions for autism, challenging behaviour and coexisting mental health problems. The guideline also contains a chapter on the experience of care for adults with autism, and their families and carers, which provides a context for the evidence reviews that follow.