Multimodal treatments for childhood attention-deficit/hyperactivity disorder: interpreting outcomes in the context of study designs.

The goal of this article was to outline issues critical to evaluating the literature on incremental benefit of multiple effective treatments used together, vs. a single effective treatment, for childhood ADHD. These issues include: (1) sequencing and dosage of treatments being combined and compared; (2) difficulty drawing valid conclusions about individual components of treatment when treatment packages are employed; (3) differing results emerging from measurement tools that purportedly measure the same domain; and (4) the resultant difficulty in reaching a summary conclusion when multiple outcome measures yielding conflicting results are used. The implications of these issues for the design and conduct of future studies are discussed, and recommendations are made for future research.