[Updates on anosognosia in Alzheimer's disease]

Impaired awareness increases dependency of patients suffering from Alzheimer's Disease (AD) and caregivers' burden but remains insufficiently evaluated in clinical practice. The numerous conceptualisations of this symptomatology (anosognosia, denial, insight…) have only a slight impact on the three main assessment methodologies which are: the patient-caregiver discrepancy; the clinician rating of patients' awareness of illness; and the prediction of performance discrepancy methods. Nevertheless, most of evaluating tools are not validated yet, in particular regarding the clinician rating, leading to contrasted results. Most of recent studies reported positive correlations with apathy and AD severity, and negative relationships with depressive symptoms. Therefore, impaired awareness seems to be mainly influenced by patient's depression and apathy. We discuss these correlates and shared aspects of apathy and impaired awareness from neuroanatomical, clinical and conceptual viewpoints. We also highlight the relevance and limits of quantitative and qualitative assessment methods, in particular phenomenological.