The presence of an interaction pattern between siblings that severely impairs the functionality of the individual or the family, or the occurrence of symptoms in one or more of the siblings, or the fact that a sibling relationship problem affects the course, outcome, or treatment of a mental disorder or health problem in one of the siblings. This category should be used when there is focus. If the focus of attention is the sibling relationship, this category can be used for both children and adults. In this context, siblings can be full, half, step, reared and acquired siblings.
