CNS drug discovery: challenges and solutions.

The worldwide market for therapies for central nervous system (CNS) disorders was valued at around US dollars 50 billion in 2001, and is set to grow sharply in the years ahead. This is because of a marked increase in the number of people aged over 65 (the "baby boomer" effect), which will lead to increased demand for more safe and effective medicines for CNS disorders. This one-day Society for Medicines Research symposium, held September 23, 2004, in London, United Kingdom, was organized by Dr. Alan M. Palmer (Pharmidex, London, U.K.) and Prof. F. Anne Stephenson (School of Pharmacy, University of London, U.K.). More than 100 delegates heard a scholarly and comprehensive review of the challenges currently facing CNS research and development, which was accompanied by consideration of a variety of innovative solution strategies. The meeting considered: 1) how to identify and validate targets for potential CNS drugs; 2) how to assess brain penetration (both in vitro and in vivo); 3) how to develop in silico methodologies to predict blood-brain barrier penetration; 4) how to assess therapeutic efficacy (both in vitro and in vivo); 5) how to establish reliable biomarkers to guide decision making; and 6) how to effectively apply magnetic resonance imaging to CNS drug discovery.