This randomized controlled multisite study has demonstrated that the NEAR technique is associated with broad cognitive improvement after 15 weeks of cognitive remediation. This cognitive improvement was accompanied by a significant improvement in psychosocial functioning.
Practice effect factors were minimized by the use of alternate forms of cognitive tests. The observed improvements were greater than practice effects usually seen on repeat testing as indicated by reliable change analyses. This is further supported by data showing that changes seen in those treated were greater than those made by a subgroup of individuals who received no NEAR treatment between 2 separate testing occasions.
This provides the first evidence to our knowledge of the effectiveness of NEAR in individuals with schizophrenia. This is also the first examination to date of the NEAR approach using an extensive battery of cognitive and psychosocial outcome measures with a longer posttreatment follow-up. The present study found improvements in visual and verbal memory, sustained attention, and set shifting that are core cognitive deficits in schizophrenia.5
The cognitive performances (particularly for sustained attention and visual memory) at posttreatment normalized to within 1 SD of the usual reference age group (20–29 years old). These effects were maintained for up to 4 months after treatment ceased. The average effect sizes were low to moderate and somewhat compatible with those obtained in previous CRT trials in schizophrenia.27
Trends toward improvement were also seen in most other cognitive domains. Further, the effects of NEAR generalized to yield an improvement in social and occupational functioning, which previously had only been measured in a small group of studies in CRT. The group of individuals in this study improved on SOFAS scores from 54 at baseline to 60–61 at posttreatment, which reflect movement from being rated as having “moderate difficulty” to “some difficulty … but generally functioning well,” which is a clinically meaningful change. Because the participants had been on a stable dose of medication for at least 2 months prior to entering the study and there were no significant changes in medication dose over the period of the study including the 4-month follow-up, this is unlikely to be due to changes in medication. Further, there were trends toward improvement in LSP and self-esteem. The latter is consistent with feedback given by participants about enhanced sense of self-worth while attending the CRT program.
The findings are in line with those found by Medalia et al28
and also other CRT work by Ueland and Rund29
that has shown that targeted repeated programs can partially remediate attention functions in schizophrenia. The results are also similar to work of Medalia et al30
in relation to observed improvements in verbal memory following NEAR. The group's performance on posttreatment moved from the impaired range to the low average range. The present results also extend Medalia's work to show NEAR's additional benefit to visual memory.
A number of limitations may potentially limit conclusions of the study. First, the sample size was small. The small size of each of the groups (wait-list, N
18, and immediate treatment group, N
22) meant that the repeated-measures (between groups) analyses yielded nonsignificant improvements in most cognitive domains, probably reflecting reduced power. On a positive note, effect sizes of some of the changes were relatively large (up to 0.90) suggesting that larger numbers within each group would have yielded more significant findings. Another limitation is that the raters were not blind to the treatment group, and therefore, the resulting increase in psychosocial ratings from pre- to posttreatment could be due to bias. Analysis of correlations between changes in subjective SOFAS ratings and objective measures of cognitive functioning yielded a significant correlation in only one domain. In addition, the functional assessment was brief. A more detailed assessment of function and how these improvements transferred to successful completion of actual daily activities would be important. Fourth, the design of the study only allowed for a short-term follow-up. Follow-up of function over 12 months would determine whether effects are sustainable and generalize to real-world functions. It may be that the full gains to be obtained from this treatment will require further treatment using more traditional psychosocial rehabilitation techniques. Further work needs to examine whether the gains found with cognitive remediation therapy are synergistic, complement, or replace these forms of treatment.
Alternative study designs are necessary to further support the utility of cognitive remediation in schizophrenia. This may include randomized controlled trials focusing on (a) demonstration of cognitive gains that extend to actual performance of activities of daily living; (b) blinding raters to treatment group membership; (c) its longer term durability (>4 months); (d) adequacy of the social control condition that matches for the therapist's time, contact, and enthusiasm; and (e) examination of the dose of treatment is required. Replication of findings in early psychosis with larger sample sizes is warranted. The applicability of NEAR to other clinical populations with similar cognitive deficits should also be explored. Recent research has shown promising results for cognitive remediation in anorexia nervosa31
It has been hypothesized that in part CRT works by training basic processes “via proliferation and refining of basic neural connections.”33
Indeed, a functional imaging study by Wykes et al33
has demonstrated enhanced neural activation postcognitive remediation. Future efficacy studies that incorporate functional neuroimaging methodology may help address such questions regarding the underpinnings of cognitive remediation.
In sum, these preliminary observations (1) support the NEAR framework (a readily available, motivating, time-effective group intervention) to guide cognitive interventions in individuals with schizophrenia, (2) provide information about which specific cognitive functions could be targeted by this cognitive intervention, (3) demonstrate that the remediation of basic cognitive deficits does appear to persist and that these effects appear to generalize to social and occupational functions.