Challenges in medication clinical trials.

The keystone of pharmacological therapy is the medication clinical trial. Beyond the straightforward administration of an adequate amount of medication for a sufficient duration of time, attention to a variety of methodologic issues is necessary to ensure a successful study. These include diagnostic and severity criteria for entry into the trial and a host of potentially confounding biological and psychosocial factors. Adequacy of treatment must be insured, aided by continued refinement of plasma drug concentration monitoring and understanding of the role of active metabolites. Outcome measures must be valid and reliable. These principles are being applied to the still-new field of child and adolescent psychopharmacology. Results thus far have indicated the importance of placebo control in young populations. The equivocal efficacy demonstrated to date for pharmacotherapy in controlled antidepressant trials in children and adolescents has limited understanding of dose (or plasma level)/response relationships which could serve to optimize further studies.