Seventeen RCTs with a total of 695 participants were included in the review.
Fourteen of the 17 included studies reported statistically significant positive results with CT, compared with the control group, for at least one outcome measure. The remaining 3 studies reported no significant differences between groups.
The weighted mean effect size across studies was 0.32 for improvements in neuropsychological performance, 0.26 for reductions in symptom severity, and 0.51 for improvement in everyday functioning; these represented small-to-medium effects.
Automated task practice.
Two of the 3 studies assessing this type of technique reported positive findings, whilst one study of occupational therapy reported negative results. The weighted mean effect size was 0.42.
Strategy-oriented task practice.
All 4 studies assessing this type of technique reported positive findings in at least one outcome. The weighted mean effect size was 0.23.
Computer-assisted automated task practice.
Six of the 8 studies assessing this type of technique reported positive findings and two reported negative findings. The weighted mean effect size was 0.49.
Computer-assisted strategy-oriented task practice.
One study assessed this type of technique. The results were positive for problem-solving, but there was no difference between groups for memory training. The mean effect size relating to memory training was -0.38.
Environmental intervention.
One study assessed an environmental intervention using cognitive adaptation training and found positive results for a number of outcomes. The mean effect size was 1.22.