Abstracts of the 3rd Biennial Schizophrenia International Research Conference / Schizophrenia Research 136, Supplement 1 (2012) S1–S375 S297 ders often occurs and is associated with poor outcome. Little is known about the causal relationship and treatment options of this comorbidity. Dopamine plays a crucial role in both disorders and both disorders are known to be associated with changes in brain structure of dopamine re- lated brain areas. In this study we evaluated whether comorbidity with cannabis use disorders affects brain volumes of patients with a psychotic disorder. Reductions in brain volumes were expected in brain regions with high density of dopamine receptors including the hippocampus, striatum, amygdala, ACC en OFC. Methods: For this study, a large sample (n=200) of patients with a recent onset psychotic disorder were offered a structural MRI scan. A comparison of brain volumes between patients with a comorbid cannabis use disorder and patients without comorbid cannabis use was made. The results will also be compared to a sample of healthy controls. Results: So far the results show that patients with comorbid cannabis use have reductions in bilateral hippocampal en amygdala volumes. More analyses including comparisons to healthy controls will be performed in the near future. Discussion: Our preliminary results suggest that cannabis use disorders have an additional effect on the brain volume alterations of patients with an early psychotic disorder and that these brain alterations are present in dopamine related brain areas. Poster #46 ALTERED WHITE MATTER CONNECTIONS IN NEVER-MEDICATED PATIENTS WITH SCHIZOPHRENIA René C.W. Mandl *, Monica Rais*, G. Caroline van Baal, Neeltje van Haren, Wiepke Cahn, René S. Kahn, Hilleke E. Hulshoff Pol Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, UMC Utrecht, Utrecht, Netherlands; *These authors contributed equally Background: Numerous diffusion tensor imaging studies have implicated white matter brain tissue abnormalities in schizophrenia. However, the vast majority of these studies included patient populations that use anti- psychotic medication. Previous research showed that medication intake can affect brain morphology and the question therefore arises to what extent the reported white matter aberrations can be attributed to the disease rather than to the use of medication. Methods: In this study we included 16 medication-naïve patients with schizophrenia and compared them to 23 healthy controls to exclude anti-psychotic medication use as a confounding factor. For each subject dif- fusion tensor imaging scans and magnetization transfer imaging scans were acquired. We introduce a new tract-based analysis that combines fractional anisoptropy (FA), mean diffusivity (MD) and magnetization transfer ratio (MTR) measurements to examine group differences in the uncinate fasciculi, arcuate fasciculi, inferior longitudinal fasciculi, inferior fronto-occipital fas- ciculi, cingulum bundles and the genu and splenium of the corpus callosum. Results: Significant group differences in combined FA, MD and MTR values were found for the right uncinate fasciculus and the left arcuate fasciculus. Additional analysis revealed that the largest part of both tracts showed an increase in MTR in combination with an increase in MD for patients with schizophrenia. Discussion: Our findings show that white matter microstructure in the brain, specifically in the left arcuate fasciculus and the right uncinate fasciculus is altered early in the disease process in schizophrenia. These alterations possibly represent disease-related axonal or glial aberrations and cannot be explained by the use of anti-psychotic medication. Poster #47 WHITE MATTER ALTERATIONS IN SCHIZOPHRENIA: A DIFFUSION TRACTOGRAPHY STUDY OF CINGULUM BUNDLE Alessia Mirigliani 1 , Mariana Gallo 1 , Antonino Buzzanca 2 , Fabio Di Fabio 1 , Marianna Frascarelli 1 , Fabrizio Parente 1 , Francesca Caramia 1 , Massimo Biondi 1 1 Department of Neurology and Psychiatry, 2 Department of Psychology, Sapienza University of Rome, Rome, Lazio, Italy Background: Structural brain changes are well documented in the neu- roimaging literature, but data have just recently been supplemented by Diffusion Tensor Imaging (DTI), which mainly assesses alterations in white matter. The dysconnectivity model suggests that abnormal integration of neural communication is central in schizophrenia. Despite white matter mi- crostructural disruptions have been observed in schizophrenia,there arestill few studies that correlate white matter pathwayswith clinical features and with cognitive impairments in schizophrenic patients. The main aim of the study is to investigate white matter alterations of the cingulate measuring fractional anisotropy (FA) of the tract between patients and healthy control groups. Other purposes are to discover any correlation between FA with symptoms assessed by PANSS (Positive and Negative Symptoms Scale) and to identify any correlation between cingulate integrity and cognitive performance assessed by Wisconsin Card Sorting Task (WCST). Methods: The sample consisted of 27 partecipants: 15 individuals with schizophrenia, 9 females and 6 males, aged from 18 to 65 years, in stable pharmacological treatment for at least 8 week, and 12 non-psychiatric controls for comparison, 7 females and 5 males, aged from 18 to 65 years. MRI was performed with a 3 Tesla Siemens scanner. Data were processed using FDT (diffusion and connectivity white matter analysis), FSL-FMRIB’s Diffusion Toolbox. For tract reconstruction we have defined two Regions Of Interest (ROI) one as seed point and the other one as waypoint mask. An exclusion mask as a portion of the brain to be excluded in shaping the section of interest was defined. FA was extracted for each subject. Both patients and controls were assessed with SCID I and II and PANSS. All participants performed WCST. Results: Factorial ANOVA for Mixed Designs demonstrated a significant difference between patients and control groups[F(1,26)= 5,068 p<0.05]. More specifically, patients had lower mean FA then control subjects both in the left and in the right cingulate. Both control and schizophrenic subjects showed a left >right asymmetry within the cingulate FA [side ef- fect; F(1,26)=12,783 p<0.01], there was no significant interaction between the two factors. The bivariate correlation analysis (patients and healthy controls) indicates a significant negative correlation between left cingulate bundle and PANSS general psychopathology (r=0.51; p<0.01 two-tailed test). The bivariate correlation analysis between WSCT scores and cingulate FA showed significant positive correlation between FA and the number of “completed categories” in all the sample (r=0.48; p<0.02 two-tailed test) and between the number of “corrected answer” and FA (r=0.49; p<0.05). There was a significant negative correlation between FA and the “errors number” of the WSCT performance (r=-0.40; p<0.05; two-tailed test), a sig- nificant negative correlation between FA and “perseverative errors number” (r=-0.40; p<0.05 two-tailed test), a significant negative correlation between FA and “perseverative answers number” (r=-0.51; p<0.01 two-tailed test), this result was also confirmed in the patients group (r=-0.54; p<0.05 two-tailed test). Discussion: Our preliminary findings show the utility of applying DTI and tractography to study white matter fiber tracts alterations in schizophre- nia. Our results confirm the presence of alterations in the cingulate in schizophrenic patients. The other results suggest that white matter alter- ations can be linked to symptoms like anxiety, somatization, depression symptoms and that lowest FA values in cingulate are correlated with poorer cognitive performance during WSCT. Poster #48 A MUTLIMODAL STUDY OF EMOTION PROCESSING IN PRODROMAL AND FIRST-EPISODE PSYCHOSIS Heline Mirzakhanian , Khalima Bolden, Kristin Cadenhead, Lisa Eyler, Pedro Roman, Gregory Brown University of California at San Diego, San Diego, CA, USA Background: Efforts to lessen the functional impact of schizophrenia can be informed by a better understanding of brain structure and function and their association at the earliest stages of the disorder. Even at early stages of illness there is a growing body of evidence suggesting white matter abnormalities subserving anatomical regions that in turn lead to disruptions in neuronal communication and eventually to abnormal brain functioning (Peters, Blaas & de Haan, 2010). In this study, we investigated both white matter integrity and brain functioning and examined the associ- ation between white matter integrity and brain functioning during emotion recognition in subjects at risk for psychosis or early in the course of their