Longitudinal studies of cognition in schizophrenia: meta-analysis.
BACKGROUND
A wide range of cognitive deficits have been demonstrated in schizophrenia, but their longitudinal course remains unclear.


OBJECTIVE
To bring together all the available information from longitudinal studies of cognitive performance in people with schizophrenia.


METHODS
We carried out a meta-analysis of 53 studies. Unlike previous reviewers, we included all studies (regardless of the type of medication), analysed each variable separately and compared results with data from controls.


RESULTS
Participants with schizophrenia showed a significant improvement in most cognitive tasks. The available data for controls showed, with one exception (the Stroop test), a similar or greater improvement. Performance in semantic verbal fluency remained stable in both individuals with schizophrenia and controls.


CONCLUSIONS
Participants with schizophrenia displayed improvement in most cognitive tasks, but practice was more likely than cognitive remediation to account for most of the improvements observed. Semantic verbal fluency may be the best candidate cognitive endophenotype.
Szöke
Andrei
A
Service de Psychiatrie Adulte, Hôpital Albert Chenevier, Créteil, France. andrei.szoke@ach.aphp.fr
Trandafir
Anca
A
Dupont
Marie-Estelle
ME
Méary
Alexandre
A
Schürhoff
Franck
F
Leboyer
Marion
M
D003072:Cognition Disorders / Q000175:diagnosis*; D006801:Humans; D008137:Longitudinal Studies; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000175:diagnosis* / Q000628:therapy; D012565:Schizophrenic Psychology; D013064:Speech Disorders / Q000175:diagnosis*