Effect of blonanserin on cognitive function in antipsychotic-naïve first-episode schizophrenia Tomomi Tenjin 1 *, Seiya Miyamoto 1 , Nobumi Miyake 1 , Shin Ogino 1 , Rei Kitajima 1 , Kazuaki Ojima 1 , Jun Arai 1 , Haruki Teramoto 1 , Sachiko Tsukahara 1 , Yukie Ito 1 , Masanori Tadokoro 1 , Kiriko Anai 1 , Yasuyuki Funamoto 2 , Yasuhiro Kaneda 3 , Tomiki Sumiyoshi 4 and Noboru Yamaguchi 1 1 Department of Neuropsychiatry, St. Marianna University School of Medicine, Kawasaki, Kanagawa Japan 2 Department of Psychiatry, Ofuji Hospital, Fuji, Shizuoka Japan 3 Department of Psychiatry, Iwaki Clinic, Anan, Tokushima Japan 4 Department of Neuropsychiatry, University of Toyama, Toyama, Japan Objective The purpose of this study was to evaluate the effects of blonanserin, a novel antipsychotic, on cognitive function in first-episode schizophrenia. Methods Twenty-four antipsychotic-naïve patients with first-episode schizophrenia participated in the study. Blonanserin was given in an open-label design for 8 weeks. The Brief Assessment of Cognition in Schizophrenia—Japanese language version (BACS-J) was administered as the primary outcome measure at baseline and 8 weeks. Clinical evaluation included the Positive and Negative Syndrome Scale (PANSS), the Schizophrenia Quality of Life Scale—Japanese language version (SQLS-J), and the Clinical Global Impression—Severity of Illness Scale (CGI-S). To exclude the possibility of retest effects on the BACS-J, 10 age-matched patients with chronic schizophrenia treated with blonanserin were tested at baseline and after an 8-week interval. Results Twenty first-episode patients completed the study. Repeated measures analysis of covariance revealed a significant group-by-time interac- tion effect on the letter fluency task due to better performance in the first-episode group, but not in the control group. Main effect of time or group- by-time interaction effect on the Tower of London task was not significant; however, the first-episode group, but not the control group, showed substantial improvement with a moderate effect size. All items on the PANSS, SQLS-J, and CGI-S significantly improved after 8 weeks of treatment. Conclusions These results suggest that blonanserin improves some types of cognitive function associated with prefrontal cortical function. Copyright © 2012 John Wiley & Sons, Ltd. key words—blonanserin; cognition; quality of life; schizophrenia; letter fluency INTRODUCTION Cognitive impairment is a core feature of schizophrenia (Gold and Harvey, 1993; Green et al., 2000) and is present early in the course of the illness (Mesholam- Gately et al., 2009; Bozikas and Andreou, 2011). A number of studies have reported a 1–2 standard deviation (SD) decline in the performance on tests of multiple cognitive domains, including attention, executive function, memory, and processing speed, compared with healthy volunteers (Saykin et al., 1994; Bilder et al., 2000; Wolwer et al., 2008; Mesholam- Gately et al., 2009). These cognitive deficits have been shown to largely determine social and occupational functioning (Green, 1996; Meltzer et al., 1996), as well as quality of life (QOL) in patients with schizophrenia (Matsui et al., 2008; Tomida et al., 2010; Woon et al., 2010). Given that cognitive deficits are among the stron- gest predictors of functional outcome in schizophrenia (Green et al., 2000), treatments for these symptoms are most urgently needed (Sumiyoshi et al., 2008; Miyamoto et al., in press). A renewed interest in the amelioration of cognitive impairment associated with schizophrenia arose with the introduction of new antipsychotic drugs. Earlier reviews suggested that the second-generation antipsy- chotics (SGAs) may have more beneficial effects on cognition than the first-generation antipsychotics (FGAs) (Keefe et al., 1999; Harvey and Keefe, 2001; Mishara and Goldberg, 2004). However, several con- founding factors, such as incomparable antipsychotic doses, heterogeneous patient samples, effects of prior medication, lack of control for retest effects on cognitive measures, and adjunctive anticholinergic medication, *Correspondence to: T. Tenjin, MD, Department of Neuropsychiatry, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511, Japan. Tel: +81 44 977 8111; Fax: +81 44 976 3341. E-mail: t2tenjin@marianna-u.ac.jp Received 14 September 2011 Revised 23 November 2011 Accepted 21 December 2011 Copyright © 2012 John Wiley & Sons, Ltd. human psychopharmacology Hum. Psychopharmacol Clin Exp 2012; 27: 90–100. Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/hup.1276