The severity of clinical symptoms was assessed using the Positive and Negative Syndrome Scale (PANSS). Neurocognitive function was tested by experienced psychologists using the Brief Assessment of Cognition in Schizophrenia (BACS) Japanese version (Kaneda et al., 2007), which is widely used in Japan (Ikebuchi et al., 2017; Itakura et al., 2017; Satogami, Takahashi, Yamada, Ukai, & Shinosaki, 2017; Sawada et al., 2017; Takahashi et al., 2013). This battery includes six subtests: list learning test (verbal memory), digit sequencing test (working memory), token motor test, verbal fluency test, symbol coding test (attention), and the Tower of London test (executive function). In the BACS, z‐scores were calculated for each subcomponent score using means and standard deviations based on the dataset of healthy Japanese populations (Kaneda et al., 2013). The composite score was calculated by averaging all z‐scores of six subcomponents.
