Serial Infidelity and Psychological Abuse: Diagnostic Blind Spots in Recognising Betrayal Trauma

ObjectiveThis narrative review examines the intersection of serial infidelity, coercive control, and psychological abuse as an under-recognised form of betrayal trauma.MethodsGuided by PRISMA principles, a systematic search of four databases (PsycINFO, PubMed, Scopus, and Web of Science) identified 47 peer-reviewed studies published between 1990 and 2025 that met inclusion criteria. Studies were included if they examined repeated infidelity within intimate relationships, associated patterns of coercive control, gaslighting (defined here as psychologically manipulating a person into questioning their own perceptions, memory, or sanity), or the psychological sequelae of sustained relational betrayal. Data were analysed using a narrative synthesis approach to identify convergent theoretical, clinical, and diagnostic themes.ResultsFindings indicate that serial infidelity frequently co-occurs with coercive and gaslighting behaviours, producing psychological effects consistent with trauma responses observed in intimate partner violence. Despite these effects, relational betrayal involving sustained deception and control remains largely absent from psychiatric nosology, contributing to diagnostic blind spots and therapeutic misclassification.ConclusionThis review highlights the distinction between moral judgement of behaviour and the clinical recognition of trauma-based harm. An evidence-informed framework is proposed for identifying betrayal trauma within diagnostic and clinical settings, emphasising trauma-informed assessment and intervention rather than behavioural or personality-based explanations.