JTC is a phenomenon common in many people in first-episode services. In this large cohort sample, no clear associations with symptoms or other psychological processes were evident. Hence, the reason people JTC is still unclear.

This work supports the notion that there is a critical time in the first few years of psychosis during which symptoms and reasoning can change. However, where reasoning style does not change, this may be associated with greater difficulties associated with delusional beliefs.

This study casts doubt on reduced global WM as an explanation of JTC. Rather it may be that the differences in reasoning are related to the manipulation of visual material and do not extend to other areas of neuropsychological functioning. However, as our sample is small it may be underpowered to detect important differences. Future work is therefore needed to replicate these findings.