An MRI study of the superior temporal subregions in first-episode patients with various psychotic disorders Tsutomu Takahashi a,b,c, ⁎, Stephen J. Wood a , Bridget Soulsby a , Yasuhiro Kawasaki b,c , Patrick D. McGorry d , Michio Suzuki b,c , Dennis Velakoulis a , Christos Pantelis a a Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne and Melbourne Health, Victoria, Australia b Department of Neuropsychiatry, University of Toyama, Toyama, Japan c Core Research for Evolutional Science and Technology, Japan Science and Technology Corporation, Tokyo, Japan d ORYGEN Research Centre, Department of Psychiatry, University of Melbourne, Victoria, Australia article info abstract Article history: Received 11 April 2009 Received in revised form 15 June 2009 Accepted 22 June 2009 Available online 16 July 2009 Morphologic abnormalities of the superior temporal gyrus (STG) have been reported in schizophrenia, but have not been extensively studied in other psychotic disorders such as affective psychosis. In the present study, magnetic resonance imaging was used to examine the volumes of the STG and its subregions [planum polare (PP), Heschl gyrus (HG), planum temporale (PT), rostral STG, and caudal STG] in 162 first-episode patients with various psychotic disorders [46 schizophrenia (31 schizophrenia and 15 schizoaffective disorder), 57 schizophreniform disorder, 34 affective psychosis, and 25 other psychoses] and 62 age- and sex-matched healthy controls. The first-episode schizophrenia patients had significantly less gray matter in HG, PT, and caudal STG bilaterally compared with all other groups, but there was no difference between the controls and affective psychosis, schizophreniform disorder, or other psychoses for any STG subregion. The STG white matter volume did not differ between groups. Our findings indicate that morphologic abnormalities of the STG gray matter are specific to schizophrenia among various psychotic disorders, implicating its role in the underlying pathophysiology of schizophrenia. © 2009 Elsevier B.V. All rights reserved. Keywords: Superior temporal gyrus Magnetic resonance imaging Schizophrenia Affective psychosis Schizophreniform disorder 1. Introduction Morphologic abnormalities of the superior temporal gyri (STG), which play a crucial role in auditory processing and language- and sociality-related functions (Gallagher and Frith, 2003; Pearlson, 1997), have been repeatedly described in previous magnetic resonance imaging (MRI) studies of schizophrenia (reviewed by Shenton et al., 2001). Gray matter reductions of the STG (Hirayasu et al., 1998; Kasai et al., 2003b; Keshavan et al., 1998; Kim et al., 2003) and its functionally relevant subregions [e.g., primary auditory cortex (Heschl gyrus, HG) or a neocortical language region (planum temporale, PT)] (Hirayasu et al., 2000; Kasai et al., 2003a) appear to be already present at first-episode of schizophrenia accompanied by further progressive changes during the early stages of illness (Kasai et al., 2003a,b; Takahashi et al., 2007), and these morphologic changes have been implicated in various psychotic symptoms such as auditory hallucinations or thought disorder (Barta et al., 1990; Rajarethinam et al., 2000; Shenton et al., 1992; Sumich et al., 2005; Takahashi et al., 2006). On the other hand, white matter findings of the STG in schizophrenia have been controversial; some MRI studies reported smaller STG white matter volume (O'Daly et al., 2007; Spalletta et al., 2003), whereas others found no changes (Antonova et al., 2005; Matsumoto et al., 2001; Sanfilipo et al., 2002; Suzuki et al., 2002) or even enlargement (Taylor et al., 2005). In addition, given the recent findings of smaller STG in schizotypal personality disorder (Goldstein et al., 2009; Takahashi et al., 2006), it remains unclear Schizophrenia Research 113 (2009) 158–166 ⁎ Corresponding author. Melbourne Neuropsychiatry Centre, c/o National Neuroscience Facility, 161 Barry St, Carlton South, Victoria 3053, Australia. Tel.: +61 3 8344 1800; fax: +61 3 9348 0469. E-mail address: tsutomu@med.u-toyama.ac.jp (T. Takahashi). 0920-9964/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.schres.2009.06.016 Contents lists available at ScienceDirect Schizophrenia Research journal homepage: www.elsevier.com/locate/schres