A systematic review of cognitive remediation for schizo-affective and affective disorders.

BACKGROUND Cognitive remediation is accepted as an important therapeutic intervention in schizophrenia, but few studies provide data on whether the benefits extend to affective disorders. OBJECTIVES To review quantitatively studies of cognitive remediation with samples that included cases of schizoaffective disorder, affective psychosis, unipolar and/or bipolar disorders. METHODS Twenty one studies met preliminary inclusion criteria, comprising a total of 940 participants of which 35% had an affective or schizoaffective disorder. Effect sizes (ES) for pre- to post-intervention change in cognitive performance were estimated. RESULTS A meta-analysis of 16 studies gave a pooled ES for change in cognitive function of 0.32 (95% Confidence Intervals 0.20 to 0.43) and produced statistical homogeneity. Overall, ES were significantly positively correlated with higher proportion of schizo-affective and affective cases (r=0.61; p=0.007), even when age, gender and duration of therapy were included as covariates in the analysis (r=.59, p=0.017). LIMITATIONS The quality of and small number of affective disorder only studies mean the findings must be treated with caution. CONCLUSIONS The estimated ES reflect those reported in the literature on cognitive remediation for schizophrenia. As such a conservative interpretation is that cognitive remediation has at least equivalent benefits in affective and schizo-affective disorder as demonstrated in schizophrenia. Further studies are urgently required to examine the durability of any gains with cognitive remediation in affective populations and to determine if any changes in cognitive deficits lead to improvements in symptoms or functioning and/or whether post-intervention cognitive changes differ in character or magnitude from those reported in schizophrenia.