Cognitive models of mental contamination (i.e. feelings of internal dirtiness without contact with a contaminant) propose that these feelings arise when individuals misappraise a violation. However, an operational definition of ‘violation’ and identification of specific violation misappraisals is limited.

This study’s aim was to elaborate on cognitive models using qualitative data from those with lived experience to fill these gaps.

Twenty participants with a diagnosis of obsessive-compulsive disorder and/or a trauma history took part in a semi-structured interview about violation. Grounded theory was used to analyse interview transcripts.

Three categories emerged, each with several themes – qualities of violation, violation-related appraisals, and violation-related behaviours. Different violation-related appraisals were associated with different emotions and urges. Specific self-focused appraisal sub-themes (i.e. permanence of consequences; self-worth; responsibility, self-blame and regret) were most closely related to emotions tied to mental contamination. These findings support and expand upon existing cognitive models of mental contamination, identifying key violation-related appraisals and differentiating between mental contamination-related appraisals and those related to other emotional sequelae. Future quantitative and experimental research can evaluate the potential of these appraisals as intervention targets.

Little is known about the impact of interpersonal betrayal experiences on mental health. Research suggests a link between betrayal and mental contamination (MC) within some forms of obsessive compulsive disorder (OCD). This study represents an initial exploration of that link in clinical samples.

A measure for assessing perceptions of betrayal was developed and evaluated (Study 1) in order to assess the extent of specificity of any association between the impact of betrayal and MC, and to estimate the extent of the impact of betrayal across common psychological disorders (Study 2).

In Study 1, the Perception of Betrayal Scale (POBS) was completed by 217 community participants; an exploratory principal components analysis identified the dimensional structure of the POBS. Study 2 was based on a cross-sectional, between-groups design, with three clinical groups [OCD (n = 23), other anxiety disorders (n = 21) and depression (n = 18)] and a non-clinical control group (n = 21). Three clinical groups (OCD, other anxiety disorders, and depression) and a community group completed a selection of measures via questionnaire.

In Study 1, the POBS was found to have an internal consistency of α = .95, and four factors were identified: preoccupation with betrayal events, belief that betrayal had caused major life change, lack of trust due to betrayal and betrayal leading to traumatic responses. In Study 2, the OCD group scored more highly in terms of maladaptive perceptions of betrayal than the other groups. Regression analysis showed betrayal scores to be a moderate predictor of the experience of MC; the POBS subscales lack of trust due to betrayal and betrayal leading to traumatic responses were found to be significantly associated with MC. Although there was some overlap with bitterness, betrayal better predicted MC.

Findings support the hypothesis of a specific relationship between the construct of betrayal and MC.