Using NMR approaches to drive the search for new CNS therapeutics

The use of MRI-based imaging in drug development has received increased interest recently because of the difficulties associated with the development of CNS pharmacotherapies. While not yet routine, there have been significant advances in imaging that allow this technology to be used for evaluating disease state and drug effects. For disease states, both single and longitudinal studies of non-invasive measures may be obtained to provide a read-out of disease processes and, potentially, to predict the disease state and its evolution. In addition, imaging has enabled the development of improved preclinical disease models based on changes in brain circuitry. Pharmacological MRI, the imaging-based evaluation of drug effects, includes measures of direct effects on the brain, as well as the effects of chronic dosing on brain changes and neurochemical changes associated with these brain effects using magnetic resonance spectroscopy. Thus, imaging may become an integrated process in drug development, during both the preclinical and clinical stages. However, validation, the implementation of good clinical practices and regulatory acceptance are hurdles that remain to be overcome.