Predictor variables in the models were group (coded CBSST = 0.5; TAU = -0.5), baseline BIS, BIS change score, group by baseline BIS and group by BIS change score interactions, and baseline ILSS score as a covariate.
CBSST participants with high insight had better functioning relative to TAU participants, but this finding was because participants in TAU with high insight had poorer functioning than those with low insight.
Given the established relationship between high insight and depression in people with schizophrenia [1,3], we conducted post hoc Chi-square and correlation analyses to explore the hypothesis that CBSST might have reduced the negative impact of insight-linked hopelessness on functioning compared with TAU, thus contributing to the moderation effect just described.
With these secondary analyses of data from our randomized controlled trial of CBSST for middle-aged and older people with schizophrenia or schizoaffective disorder, we sought to determine whether insight moderated treatment outcome.
A non-significant trend was also found showing lower rates of people with hopelessness at 12-month follow-up in CBSST than in TAU, with half as many people with hopelessness in CBSST than in TAU.
The absence of a treatment effect on insight indicates that change in insight did not mediate outcome in CBSST .
Insight, especially insight into need for treatment, moderated the relationship between treatment group and functioning, such that CBSST offset the negative effect of insight on functioning with TAU.