[First-episode psychosis, cognitive difficulties and remediation]

Abstract

Cognitive difficulties are a core feature of schizophrenia. They are frequent, severe, and clearly associated with functional disabilities. They have been explored during different phases of the disease, but what we know essentially concerns the chronic period in middle-age patients. In this article we will specifically focus on cognition at the time of first episode. First episode is a key life period, occurring while social demands are increasing and more complex on the one hand, and while there are important changes in structural and functional cerebral anatomy on the other hand. Exploring cognitive difficulties at the time of first episode offers the opportunity to better know their time course, to avoid interpretative difficulties due to the chronicity of the disease and its treatments, and to develop early therapeutics in order to improve outcome. Cognitive difficulties are clearly present at the time of first episode; their nature and severity appear similar to those observed in more chronic patients. Therefore, they cannot be entirely explained by treatments, hospitalizations or chronicity, and appear more as an intrinsic feature of the disease. The course of their trajectory through the progression of the disease remains uncertain; while they are already present during childhood or adolescence in some subjects who will later declare schizophrenia, they seem to worsen during the period of early prodroms, that is years before psychotic symptoms emerge. Whether they aggravate again during the first episode process is still a matter of debate. While longer DUP is associated with a poor outcome, this does not seem to hold true for cognitive impairments. Cannabis or tobacco use are neither associated with worse cognitive abilities in first-episode patients; a reverse relationship even sometimes exists. Cognitive impairment appears as largely independent from other clinical dimensions, acknowledging its own physiopathology and requiring specific evaluation and treatment. Several cognitive batteries can be used in clinical practice to explore cognitive abilities in first-episode patients; this is a necessary step before treating. While current pharmacological treatments display little or no efficacy for treating cognitive impairments, new medications offer some hope for the future. Still, efforts especially concern cognitive remediation for the moment. Several programs can be used in patients following their first episode, and some studies suggest that deficits in cognition are more amenable to remediation during earlier phases of the illness especially when cognitive remediation is associated with psychosocial rehabilitation, including school or work support. In the future, exploring and treating cognitive difficulties in first episode patients appear as a matter of collaborative work between psychiatrists and cognitive psychologists and between health and social services.

Keywords: Cognition; Cognitive remediation; First episode; Premier épisode; Psychose; Psychosis; Remédiation cognitive; Schizophrenia; Schizophrénie.