Voxel-based morphometry (VBM) is a neuroimaging analysis technique that allows investigation of focal differences in brain anatomy, using univariate and multivariate statistical approaches by means of statistical parametric mapping (SPM). VBM represents an unbiased, objective and comprehensive method for testing differences in local composition of brain tissue after discounting global shape differences. Under the assumption of dynamic changes in brain structure due to genetic, developmental or environmental influences the main focus of our group is the quantification of such macroscopic brain changes in patients with schizophrenia, affective disorders as well as with obsessive-compulsive disorder. Using the multimodal approach our further research focus is to relate functional brain abnormalities to local structural abnormalities in gray and white matter composition.