[Learning potential and cognitive remediation in schizophrenia]

Abstract

Background: Many studies have stressed the importance of neurocognitive deficits in schizophrenia that represent a core feature of the pathology. Cognitive dysfunctions are present in 80% of schizophrenic patients, including deficits in attention, memory, speed processing and executive functioning, with well-known functional consequences on daily life, social functioning and rehabilitation outcome. Recent studies have stressed that cognitive deficits, rather than the positive or negative symptoms of schizophrenia, predict poor performance in basic activities of daily living. If it is possible to reduce psychotic symptoms and to prevent relapses with antipsychotic medication, it is not yet possible to have the same convincing impact on cognitive or functional impairments. Cognitive remediation is a new psychological treatment which has proved its efficacy in reducing cognitive deficits. A growing literature on cognitive rehabilitation suggests possibilities that in schizophrenia, specific techniques are able to enhance an individual's cognitive functioning.

Literature findings: Presently, two distinct and complementary cognitive remediation methods have been developed: the compensatory and the restorative approaches: (A) restorative approaches attempt to improve function by recruiting relatively intact cognitive processes to fill the role of those impaired, or by using prosthetic aids to compensate for the loss of function; (B) in contrast, in the restorative approach cognitive deficits are targeted directly through repeated practice training. However, results concerning cognitive remediation remain inconsistent. It is clear that not all individuals with schizophrenia display cognitive impairment, and even among those who do, the specific pattern of cognitive functioning varies. Moreover, traditional neurocognitive assessment, with a single or static administration of cognitive measures, provides moderately good prediction of skills acquisition in schizophrenia. Among other factors such as motivation, awareness of having a disease and acuteness of symptomatology, some studies have exposed that a cognitive variable, learning potential could mediate in part the effectiveness of cognitive remediation.

Discussion: The concept of learning potential is used to explain some of the observed variability in cognitive functioning. Learning potential is the ability to attain and utilize cognitive skills after cognitive training: it is assessed by individual variation in performance across three consecutive administrations of the Wisconsin Card Sorting Test (WCST): a pretest with standard instruction procedures, a training phase with expanded instruction and a post test with only standard instruction. Three learner subtypes can be identified: "learners" who perform poorly at the pretest but improve performance during the post-test, "non-retainers" who perform poorly at pre-test and do not improve at post-testing and "high achievers" who perform well in the initial pretest and maintain their good performance across the other two administrations. The assessment of learning potential could predict, with other psychological measures such as insight and motivation, the most effective neurocognitive rehabilitation program for an individual patient, and could help the clinician to optimize patient outcome through appropriate individual management.

Conclusion: Indeed, learning potential could represent a good cognitive predictor and indicator for rehabilitation in schizophrenia for clinicians and should be used in cognitive assessment practice. However, the individuals most likely to benefit from cognitive remediation, and whether changes in cognitive function translate into functional improvements, are as yet unclear.