Additionally the difference needs to be a std deviation or two away from the normal population. ADHD in particular has effects on specific sub-tests in IQ exams

Additionally the difference needs to be a std deviation or two away from the normal population. ADHD in particular has effects on specific sub-tests in IQ exams. It’s quite a clear pattern which emerges as the ares of IQ dealing with multiple conflicting inputs tend to be standard deviation below the rest of the sub-tests norms for a person. Unfortunately I don’t know the appropriate literature to cite. Another test which is used is response times to an onscreen test.