Perfectionism is defined as exceedingly high standards of performance accompanied by critical evaluations of oneself and others and a fear of negative social evaluation if not perfect. Factorial analyses of the two main perfectionism scales have identified two overarching dimensions: Perfectionistic Strivings and Perfectionistic Concerns. The perfectionistic concerns dimension is generally associated with negative outcomes and psychopathology, while perfectionistic strivings have been found to yield both positive outcomes and negative outcomes.~Perfectionism is a central transdiagnostic phenomenon involved in the maintenance of multiple psychological disorders (e.g., anorexia nervosa, obsessive compulsive disorder, chronic fatigue, and depression). After decades of research focusing on scales development or relying exclusively on correlational studies, the experimental investigation of the processes underlying perfectionism is just emerging. On a theoretical basis, two processes related to emotional information processing seem particularly relevant: rumination and autobiographical memory. The objective of this study is to investigate with a randomized, concurrent, multiple-baseline single-case design the contribution of these processes to perfectionists' psychological vulnerability.~Rumination is defined as a mental process characterized by repetitive, prolonged, and recurrent thinking about one's concerns and one's experience. The control theory suggests that individuals engage in rumination when perceiving a discrepancy between their goals and their current condition, and stay in this mode of thinking until the goal is either attained or abandoned. Based on this theoretical background, recent research suggests that rumination could be one of the processes explaining the perfectionistic vulnerability to psychological distress, by perseveringly focusing on the discrepancy between high and demanding standards and the actual performance. However, only few study has experimentally manipulated this process, thus precluding from any causal inference.~Autobiographical memories are memories about personal experiences that go beyond the mere factual description of the event to include personal beliefs, emotions, and thoughts. One feature of those memories is the specificity level defined as the extent to which retrieved autobiographical memories are specific or not (i.e., memory of a particular event that happened at a particular time and place that lasted no more than one day). Difficulty with retrieving such specific memories is called overgeneral autobiographical memory.~The perfectionism cognition theory aims to clarify how autobiographical memory and working memory might be affected by perfectionist tendencies. It especially postulates retroactive loops between (a) repetitive thinking, (b) an overdeveloped memory for mistakes, failures, and stressful experiences, and (c) a hypervigilance and cognitive bias toward related cues that signal the possibility of failure, mistakes, and negative social evaluation. These authors suggested that perfectionists are characterized by deficits in attentional capacity and working memory during times of stress. This promising cognitive approach has partially been supported. For example, a recent meta-analysis states that perseverative cognitions (i.e., worry and rumination) mediate the relationship between perfectionism and distress in non-clinical samples. However, empirical evidence of an experimental nature is still needed, in particular for the postulated autobiographical memory and working memory biases.~To overcome those limitations, the present study will manipulate rumination with a clinical intervention, to block its mediational role on the relationship between perfectionism and psychological distress (here operationalized by mood state and anxio-depressive symptoms). Moreover, this study aims to go further than identifying a true mediator: its aims to explain the mechanism through which change come about, namely through a concreteness training to overcome overgeneral mode of processing. Indeed, even if the main focus of the study is to identify mediators that may statistically account for the relationship between perfectionism and psychological distress, a ideal purpose is to propose a therapeutic intervention that may target mechanisms of change underlying hypothesized mediator.
This study aims to investigate the mediating role of rumination in the relationship between perfectionism and psychological distress, by proposing a cognitive-behavioral intervention targeting rumination. This intervention aims at decreasing - or even neutralizing - the effect of the mediator and then examining how this decrease impacts the relationship between perfectionism and psychological distress.~A randomized, concurrent, multiple-baseline single-case design will be applied.