I find it hard to answer the third question in relation to this request. The investigators seem to want the clinical assessment data from this trial, especially ADHDRS-IV, to help to validate a new assessment system (IRT). I am not sure that this is feasible. But on balance I think it would be legitimate to allow them access to the data, and let the academic and clinical community decide on validity when they publish their results.
Recommendation for this data request: Approve