Study Report

Reference	Chakirova, G.,2011 PMID: 21376542
Citation	Chakirova, G., H. C. Whalley, et al. (2011). "The effects of DISC1 risk variants on brain activation in controls, patients with bipolar disorder and patients with schizophrenia." Psychiatry Res 192(1): 20-28.
Disease Type	Bipolar I Disorder & Schizophrenia
Study Design	case-control
Study Type	Candidate-gene association study
Sample Size	healthy volunteers (n=33), patients with schizophrenia (n=20) and patients with bipolar disorder (n=36)
SNP/Region/Marker Size	3 SNPs
Predominant Ethnicity	Caucasian
Population	British
Gender	55.6% male in BD patients ,65.0% male in SZ patients and 54.6% male in controls
Age Group	Adults : Mean age(SD)(year):39.3(10.8) in BD patients ,37.0(10.1) in SZ patients and 37.3(12.1) in controls

Sample Diagnosis	DSM
Sample Status	Detailed information about the recruitment of these individuals has been provided previously (McIntosh et al., 2008).
Technique	genotyping and Magnetic resonance imaging (MRI) scans
Statistical Method	At the individual subject level, the data were modeled with five conditions (the four difficulty levels and the rest condition), each modeled by a boxcar convolved with a synthetic hemodynamic response function (McIntosh et al., 2008).All second level statistical analyses were conducted in SPM8 due to the improved factorial modeling available in this version of the software.
Result Summary	In the healthy controls the risk associated allele carriers of SNPs rs1538979 and rs821633 demonstrated decreased activation of the cuneus. Moreover, there was an effect of SNP rs1538979 in the pre/postcentral gyrus with decreased activation in healthy controls and increased activation in patients with schizophrenia. In the bipolar group there was decreased activation in the risk carriers of SNP rs821633 in the inferior parietal lobule and left cingulate cortex. Clusters in the precentral gyrus, left middle temporal gyrus and left cerebellum were found to be significant on examining the group x genotype interactions. These findings may provide a better understanding of the neural effects of DISC1 variants and on the pathophysiology of schizophrenia and bipolar disorder.