Study limitations
This study had some methodological limitations that warrant consideration. First, we assigned participants to the intervention or control group according to their order of arrival rather than strict group randomization, which might limit generalization of our findings. In addition, there was no group matching for age. Thus, future studies are needed to cross-validate our findings in the same population. Second, we used a single-referral source (a professional support center), which might bias the sample regarding the PANSS severity in some way. The possibility of low heterogeneity in repeated studies should be addressed. The PANSS does not reflect the new generation scale like CAINS which specifically focuses on distinguishing the expressive component of negative symptoms. In addition, the WCPA focuses on evaluating only EF, but the cognition and metacognition concepts are broader than just EF.