Assessing the efficacy of treatments for ADHD : overview of methodological issues.

Attention-deficit hyperactivity disorder (ADHD) is a common and impairing psychiatric condition that affects significant numbers of children, adolescents and adults. Clinicians in a variety of practice settings (hospital, outpatient, residential, research) strive to diagnose, treat and monitor ADHD in an efficient and evidence-based manner. Tools that facilitate the gathering and interpretation of information from a variety of sources can effectively augment a diagnostic assessment, and can also be useful for longitudinal monitoring. Multiple assessment tools are available, with varying degrees of psychometric validity, clinical utility and overall feasibility (time and cost). This review provides an overview of several available ADHD rating scales and continuous performance tests, and offers a discussion of potential strengths and weaknesses of the instruments. While these tools do not in and of themselves make a diagnosis of ADHD, they can certainly assist in the diagnostic assessment, be crucial in assessing the efficacy of medications in clinical trials, and be a useful adjunct in the clinical management of ADHD.