This Second Edition updates and expands on the original editorial content and coverage, including new chapters on definitions and rationale, a general overview, research on mental health disorders, report writing, the role of treatment planning, and treatment associated with mental health disorders. The Second Edition builds on the knowledge base by providing the most current information on all aspects of each topic. This unique volume addresses basic questions in salient detail, from types and rates of challenging behaviors to populations that warrant functional assessment. In addition, it examines typical assessment techniques, including interview, scaling, experimental, and in vivo methods. The use of functional assessment in treatment planning - and in combination with other interventions - is covered in depth. Given the vulnerable populations and challenging behaviors (e.g., individuals with autism, intellectual disabilities, mental health issues), the book provides detailed coverage of informed consent as well as legal and ethical issues. Key areas of coverage include: The history of behavior analysis and functional assessment. The nature, prevalence, and characteristics of challenging behaviors. Interview and observation methods in functional assessment and analysis. Experimental functional analysis for challenging behaviors. Treatment methods commonly used with functional assessment. Using functional assessment in treatment planning. Functional Assessment for Challenging Behaviors, Second Edition, is an essential updated resource for researchers, clinicians and other practitioners, and graduate students in clinical child and school psychology, pediatric psychiatry and medicine, social work, rehabilitation, developmental psychology as well as other interrelated disciplines.