Functional mechanisms of episodic memory impairment in schizophrenia

Objective: To achieve a better understanding of the functional mechanisms underlying episodic memory dysfunction in schizophrenia, which is a prerequisite for unravelling schizophrenia's neural correlates in neuroimaging studies and, more generally, for developing an integrated approach to the pathophysiology of schizophrenia. It is also crucial for developing cognitive remediation. Method: This paper reviews empirical evidence of episodic memory dysfunction in schizophrenia obtained with reference to various theoretical models of episodic memory. Results: All the studies converge to show a significant impairment of the critical feature of episodic memory: conscious recollection. Schizophrenia is also associated with a defect of autobiographical memory. The episodic memory dysfunction results from a predominant failure of strategic processing at encoding, although an impairment of strategic processing at retrieval cannot be ruled out. The possibility that it is not the execution of the encoding strategies that is defective but, rather, their self-initiation by the patients is plausible. Conclusions: These findings may explain some behavioural abnormalities associated with schizophrenia, notably, inadequate functional outcomes in everyday life. They may also have implications for cognitive remediation and better social and work functioning of patients with schizophrenia.