The International Society for CNS Clinical Trials and Methodology (ISCTM) held its 4th Annual Autumn Conference in Toronto, Ontario, October 6-7, 2008. The purpose of the present report is to provide an overview of one of the sessions at the conference which focused on the designs and methodologies to be applied in clinical trials of new treatments for Alzheimer's disease (AD) with purported “disease-modifying” effects. The session began with a discussion of how neuroimaging has been applied in multiple sclerosis clinical trials (another condition for which disease modification claims have been achieved). The next two lectures provided a pharmaceutical industry perspective on some of the specific challenges and possible solutions for designing trials to measure disease progression and/or modification. The final lecture provided an academic viewpoint and the closing discussion included additional academic and regulatory perspectives on trial designs, methodologies, and statistical issues relevant to the disease modification concept.