Psychological traits predict impaired awareness of deficits independently of neuropsychological factors in chronic traumatic brain injury

Objectives: To dissociate injury-related factors from psychological contributions to impaired awareness of deficits following traumatic brain injury (TBI); impaired awareness is theorized to partly reflect psychological factors (e.g., denial), but empirical evidence for this theory is scarce. Design: We examined how different factors predict awareness in patients undergoing rehabilitation (N = 43). Factors included (1) neurological (injury severity), (2) neuropsychological loss, (3) psychological (denial, projection, identification), and (4) personality (narcissism). Methods/Main measures: The Patient Competency Rating Scale, comparing patient with clinician reports on different functional domains; the Thematic Apperception Test, an injury-independent measure of the propensity to mobilize specific defence mechanisms; and the Narcissism Personality Inventory. Results: Impaired awareness was not predicted by injury-related and neuropsychological scores but was significantly predicted by use of primitive defence mechanisms (denial and projection). Patients who underestimate their abilities also demonstrated high denial levels, but contrary to underestimators, this was positively related to depression and negatively to awareness. Conclusions: Primitive defence mechanism use significantly contributes to impaired awareness independent of injury-related factors, particularly in domains associated with self-identity. Well-validated tests of defence mechanism mobilization are needed to support clinical interpretation of and intervention with impaired awareness. More research is needed to understand the psychology of hypersensitivity to deficits. Practitioner points: This study provides an empirical demonstration of dissociable contributions of neurological and psychological factors to awareness of deficits in TBI. Trait proclivity to mobilize defence mechanisms in response to anxiety-provoking situations can be measured, and strongly predicts impaired awareness. Importantly, measures of psychological reactions were independent of responses to the neurological deficits themselves, discriminating between psychological and neurological contributions to impaired awareness. The importance of identifying psychological reactions to impaired awareness and hindering rehabilitation success is highlighted, and vital for clinicians to consider during the rehabilitation process. Psychological reactions to TBI can be identified using well-validated, quantitative measures of the use of psychological defences (e.g., Cramer's Thematic Apperception Test scoring system), and the authors suggest this is a critical step to properly characterize and manage awareness in patients during treatment. Although only TBI patients were examined, the results may inform impaired awareness that occur as a result of other disorders and illnesses. The patients in this study were in the chronic stages of the injury, and therefore, the results may not generalize to patients in more acute stages.