Response-Class Hierarchies in Self-Induced Vomiting: Functional Assessment and Treatment

Individuals with neurodevelopmental conditions sometimes engage in self-induced vomiting, a behavior associated with serious medical complications and increased risk of exposure to communicable diseases. Despite its clinical significance, the functional dimensions of self-induced vomiting remain understudied, particularly in cases where it occurs within a hierarchical response class of attention-maintained behavior. This study describes the functional assessment and treatment of self-induced vomiting in an adolescent male with multiple neurodevelopmental conditions. A response class hierarchy analysis was conducted to evaluate whether self-induced vomiting, self-gagging, pica, and other challenging behaviors were functionally related. Findings revealed systematic shifts in challenging behavior topographies with sequential exposure to extinction, supporting the presence of a hierarchically organized response class maintained by attention. Treatment involved functional communication training, extinction, and an individualized levels system involving token reinforcement and a probabilistic exchange schedule. This multicomponent intervention eliminated self-induced vomiting, self-gagging, pica, and other challenging behaviors within the attention-maintained response class. These findings underscore the need for function-based assessments in the treatment of self-induced vomiting and related behaviors.