Confirmatory Efficacy of Cognitive Enhancement Therapy for Early Course Schizophrenia: Results from a Multi-Site Randomized Trial

Background and Purpose: Schizophrenia is a chronic and disabling mental health condition. The early application of cognitive remediation interventions has provided some of the greatest hope for reducing long-term disability and improving community functioning in the condition. Cognitive Enhancement Therapy (CET) is an effective social work intervention that integrates both computer-based neurocognitive training and structured social-cognitive groups to improve cognition and functioning in the early course of schizophrenia. The current study seeks to confirm the previously observed effects of CET in the early course of the condition in a larger multi-site clinical trial (Eack et al., 2009).

Methods: A total of 106 (Pittsburgh: n = 54; Boston: n = 52) early course schizophrenia outpatients were randomized to either 18 months of CET (n = 61) or an Enriched Supportive Therapy (EST; n = 45) comparison treatment. Participants completed a comprehensive battery of cognitive, functional, and clinical assessments at baseline, 9 (mid-treatment), and 18 months (end of treatment). Composite indexes were calculated for neurocognition, social cognition, functional outcome, and symptomatology. Intent-to-treat linear mixed-effects models were used to investigate differential change trajectories in outcomes between CET and EST. The group (CET vs. EST) x time (baseline, 9, and 18 months) interaction was the primary effect of interest.

Results: No significant group x time interactions were observed for either neurocognition (F^2,109 = .11, p = .901) or clinical symptoms (F^2,110 = .22, p = .800). CET demonstrated a particularly favorable effect on social cognition, such that over the 18 months of treatment, relative to the individuals in the EST treatment group, those in CET had significantly greater gains in social cognitive abilities (F^2,113 = 3.31, p = .040, d^{between-group} = .52). Greater improvements in social cognition were observed in the CET group at both the 9 (t¹¹³ = 2.45, p = .016) and 18 month (t¹¹³ = 1.91, p = .059) time points compared to EST. Individuals in the CET group also demonstrated greater improvements in functional outcome overtime relative to the EST treatment group (F^2,110 = 3.55, p = .032, d^{between-group} = .32).

Conclusions and Implications: These results continue to support CET as an effective social work intervention for improving social cognitive and functional outcomes among individuals in the early course of schizophrenia, largely confirming the findings from the initial trial (Eack et al., 2009). Such evidence underscores the impact of CET on reducing disability and improving community functioning when applied as an early course intervention for individuals living with the condition.

References

Eack, S.M., Greenwald, D.P., Hogarty, S.S., Cooley, S.J., DiBarry, A.L., Montrose, D.M., & Keshavan, M.S. (2009). Cognitive Enhancement Therapy for early schizophrenia: Effects of a two-year randomized controlled trial. Psychiatric Services, 60(11), 1468-1476. doi: 10.1176/appi.ps.60.11.1468.