CLINICAL HANDBOOK OF SCHIZOPHRENIA

25. Cognitive Rehabilitation 253FIGURE 25.2. Average effect sizes for cognitive outcomes following CRT from meta-analyses. FromKrabbendam and Aleman (2003). Copyright 2003 by Springer-Verlag. Reprinted by permission.of cognitive-behavioral treatments. All but one meta-analysis has shown a positive effectso there does seem reason to exploit this therapy (Krabbendam & Aleman, 2003; Kurtz,Moberg, Gur, & Gur, 2004; Twamley, Jeste, & Bellack, 2003). But improving cognitionis not under dispute. The real question is, do these cognitive improvements have an effecton real-life functioning? There is evidence of modest effects on positive and negativesymptoms (effect size for overall symptom severity = 0.26), and more robust effects forsocial functioning (0.51). There are also some emerging data that cognitive remediationaffects the number of hours worked. Most importantly many of these effects are durable.For instance 58% people who receive cognitive remediation and work rehabilitation werestill in paid employment 12 months after the end of treatment, whereas only 21% ofthose who received work rehabilitation alone were still at work at this time (Wexler &Bell, 2005).So there is evidence of positive effects on functioning outcomes. This assumes thatremediation acts on cognition, and that this improvement leads to changes in real-lifefunctioning. But the empirical data now point to a different model, one in which improvementsin cognition have to be moderated by cognitive rehabilitation, because evenwhen cognition improves in the control group, there is little evidence of improvement onfunctioning; in addition, nonresponders to cognitive remediation have less chance of improvingtheir functioning. The effect on outcome seems to depend solely on the cognitiveimprovements produced by cognitive rehabilitation.TYPES OF COGNITIVE REHABILITATIONWhat is cognitive rehabilitation? This question has come rather late, because it is themost difficult to answer. Cognitive rehabilitation has been led by pragmatic studies thatattempt to demonstrate individuals’ cognitive improvement. The training programsadopted have face validity, but there have been many different approaches: