A Four-Step Approach for Developing Diagnostic Tests in Psychiatry: EEG in ADHD as a Test Case

A four-step approach for developing diagnostic tests in psychiatry is proposed. The approach was applied to a promising finding (increased electroencephalogram [EEG] Theta in attention deficit hyperactivity disorder [ADHD]). A meta-analysis for the effect sizes was performed. Seventeen studies were included (12 met criteria for inclusion in the meta-analysis). The majority of papers met criteria for Step 1. A number of papers qualified for Step 2 or Step 3. The effect size of the total sample for absolute theta was 0.58 and for relative theta 0.92. The proposed schema was able to classify a representative biological finding into a specific phase of development as a diagnostic tool. Based on the meta-analysis, the authors conclude that increased EEG theta activity in ADHD is promising and should be further developed as a diagnostic test.