Research That Matters (January 17 - 20, 2008)

Purpose: Ample literature finds a strong relationship between neurocognition and subsequent functional change in schizophrenia. There is, however, no literature on whether neurocognitive improvement occurs during psychosocial rehabilitation, and whether neurocognitive improvement is related to functional change. The purpose of this study was to examine functional and neurocognitive improvement during community-based psychosocial rehabilitation for individuals with schizophrenia, and to examine how these factors are linked. The interaction of neurocognitive change, functional change, and treatment intensity was also examined.

Method: The sample consisted of 130 individuals diagnosed with schizophrenia who were recruited upon admission to three similar community-based psychosocial rehabilitation interventions. The subjects were assessed at baseline and then prospectively at 6 and 12 months on the Role Functioning Scale which measures work, social, and independent living functioning. Neurocognition was measured at baseline and 12 months later. Neurocognition was constructed with five tests reflecting verbal fluency, working memory, episodic memory, sustained attention, and mental flexibility. Treatment intensity was measured as the number of days treatment was received during the one-year study period. Data were analyzed using latent growth and longitudinal structural equation modeling.

Results: There was statistically and clinically significant functional improvement over 12 months (large effect size). Neurocognition (NC) improved significantly over time (medium effect size). 76 (58%) of the sample showed neurocognitive improvement over 12 months while 54 (42%) did not. There was a significant rate of functional enhancement in the NC improver group (large effect size). There was a non-significant rate of functional change in the NC non-improver group. NC improvers showed a rate of functional improvement that was 350% greater than NC non-improvers. Treatment intensity did not vary between NC improvers and non-improvers, but there was a strong interaction between NC improvement, treatment intensity, and rate of functional improvement over 12 months. This interaction suggested that treatment intensity had a large and positive effect on functional outcome for the NC improvers, but not for the NC non-improvers. Medication usage and symptomatology did not confound these findings.

Conclusions and Implications: Neurocognitive improvement appears to be a critical factor in functional change and treatment responsiveness during community-based psychosocial rehabilitation for individuals with schizophrenia. There is a strong person-environment interaction such that treatment intensity is strongly related to functional improvement for NC improvers but not for NC non-improvers. These findings can form a basis for understanding the conditions and mechanisms of functional change during psychosocial rehabilitation. Given the importance of NC change, future research should focus on understanding for whom and how neurocognitive change occurs so that treatments can be individualized, and new interventions can be developed. Social work interventions for schizophrenia must attend to NC and NC improvement as critical factors in treatment effectiveness and intervention design.