Contextual explanation: Wrongdoing by an institution toward dependents. 
Institutional betrayal is best understood as a societal phenomenon—specifically, when an established organisation or system fails those who rely on it, either by neglecting to prevent harm, responding inadequately to reports of harm, or exacerbating trauma through its actions or inactions.

Themes: Trust and accountability. 
Institutional betrayal is closely tied to the theme of trust, as institutions are expected to protect and support their members. When this trust is broken, the concept highlights the importance of accountability and the consequences of institutional failure on individuals and communities.

Nuance: Failure to protect or respond supportively. 
What distinguishes institutional betrayal within its category is the focus on harm caused not by individuals, but by the systems and structures meant to safeguard people. The nuance lies in the institution's failure to act, inadequate response, or actions that worsen the situation for those dependent on its integrity.