Henry J. Riordan and Neal R. Cutler at Worldwide Clinical Trials
discuss how the biomarkers can aid in the development of novel
therapeutic agents by supporting patient selection or enriching
trials with patients more likely to have a psychiatric illness
(diagnostic and prognostic biomarkers); by enriching and stratifying
inclusion criteria (predictive biomarkers); and by serving as an
indicator of drug activity or as a surrogate for clinical outcome
or safety (pharmacodynamic biomarkers). The expanding use of
biomarkers has raised many challenges in both the design and
conduct of clinical trials and has underscored the need to establish
a standard methodology that helps ensure valid data in support of
these biomarkers.